COVID-19 Data Dispatch

Category: Testing

  • Answering reader questions: Incubation period, vaccines coming this fall, nasal sprays

    I received a couple of reader questions in recent weeks that I’d like to answer here, in the hopes that my responses will be more broadly helpful. As a reminder, if you ever have a COVID-19 question that you’d like to ask, you can email me at betsy@coviddatadispatch.com, or send it anonymously through this Google form.

    COVID-19’s incubation period

    One reader asked:

    I’d love to learn more about COVID’s incubation period. I have read that it’s 2 to 14 days … but the median time seems to be on the low end (and could be as low as 24 hours?) How likely is it that it’s more like 14 days? I’d love to better understand this so that I know how to better handle exposures… Should I avoid someone who has had an exposure for two full weeks?

    This is a tricky question for two reasons. First, the incubation period—or the time between exposure to COVID-19 and starting to show symptoms of infection—does indeed vary a lot. One review of studies on this topic, posted as a preprint in May, found a range from two to seven days, though it can be even longer. The CDC recommends precautions for up to ten days after exposure.

    Second, the incubation period has changed as the coronavirus has mutated. The virus is constantly evolving to keep infecting us even as people build up immunity; shortening the incubation period is one of its strategies. Omicron has a notably shorter period than past variants; Katherine Wu at The Atlantic wrote an article about this in December 2021 that I think is still informative.

    The preprint I cited above found that Omicron had an average incubation period of 3.6 days, shorter than other variants. I think it’s reasonable to assume that this period has continued to get shorter as Omicron has evolved into the many lineages we’re dealing with now. But the pace of research on this topic has slowed somewhat (with less contact-tracing data available for scientists to work with), so it’s hard to say for certain.

    So, with these complexities in mind, how should one handle exposures? My personal strategy for this (noting that I’m not a doctor or qualified to give medical advice, just sharing my own experience) is to rely on a combination of timing, testing, and symptom monitoring. For the first couple of days after exposure, you wouldn’t be likely to have a positive test result even if you are infected, as it takes time for enough virus to build up in the body for tests to catch it. So, for those days, I’d just avoid people as much as possible.

    After three to four days, PCR tests would start to be effective, and after five to six days, rapid tests would be. So at that point, I’d start testing: using a mix of PCR and rapid tests over the course of several days, up to two weeks after exposure. Studies have shown that the more tests you do, the more likely you are to catch an infection (and this applies to both PCRs and rapids). Daily is the best strategy, but less frequent regimens can still be useful if your access to tests is limited. At the same time, I’d keep track of any new symptoms, as that can be a sign of infection even if all tests are negative.

    I’d personally be comfortable hanging out with someone who has had an exposure but consistent negative test results and no symptoms. But others who are less risk-tolerant than I am might avoid any contact for two weeks. The type of contact matters, too: a short, outdoor meeting or one with masks on is safer than a prolonged indoor, no-mask meeting.

    Vaccine effectiveness

    Another reader asked:

    Is there any information on the effectiveness of the latest vaccines, including vaccines that combine Covid and RSV, and are there similarities between these viruses (related?)

    As we head into respiratory virus season in the U.S., there will be, for the first time, vaccines available for all three major diseases: COVID-19, the flu, and RSV. I’ll talk about effectiveness for each one separately, because they are all separate vaccines for separate viruses. There’s no combined COVID-RSV vaccine on the market.

    COVID-19: We know the fall boosters will target XBB.1.5, a variant that has dominated COVID-19 spread in the U.S. recently. There isn’t much data available on these vaccines yet, because the companies developing them (Pfizer, Moderna, Novavax) have yet to present about their boosters to the FDA and CDC, as is the typical process. The CDC’s vaccine advisory committee is meeting this coming Tuesday to talk fall vaccines, though, so it’s likely we will see some data from that meeting.

    Also worth noting: some early laboratory studies suggest that vaccines based on XBB.1.5 will provide good protection against BA.2.86, despite concerns about differences between these variants. (More on this later in today’s issue.)

    Flu: Every year, scientists and health officials work together to update flu vaccines based on the influenza strains that are circulating around the world. Effectiveness can vary from year to year, depending on how well the shots match circulating strains.

    This week, we got a promising update about the 2023 flu vaccines: CDC scientists and colleagues studied how well these shots worked in the Southern Hemisphere, which has its flu season before the Northern Hemisphere. The vaccine reduced patients’ risk of flu-related hospitalization by 52%, based on data from several South American countries that participate in flu surveillance. This is pretty good by flu vaccine standards; see more context about the study in this article from TIME.

    RSV: There are two new RSV vaccines that will be available this fall, both authorized by the FDA and CDC in recent months. These vaccines—one produced by Pfizer, one by GSK—both did well in clinical trials, reducing participants’ risks of severe RSV symptoms by about 90% (for the first year after infection, with effectiveness declining over time).

    Both vaccines were authorized specifically for older adults, and Pfizer’s was also authorized for pregnant people as a protective measure for their newborns. We’ll get more data about these vaccines as the respiratory virus season progresses, but for now, experts are recommending that eligible adults do get the shots. This article from Yale Medicine goes into more details.

    Nasal sprays as COVID-19 protection

    Another reader asked:

    I’m thinking of researching what foods and supplement are anti-viral anti-COVID. I’m wondering if anyone has done any research on that?

    I haven’t seen too much research on about foods and supplements, since dietary options are usually not considered medical products for study. Generally, having a healthy diet can be considered helpful for reducing risk from many health conditions, but it’s not something to rely on as a precaution in the same way as you might rely on masking or cleaning air.

    Another thing you might try, though, would be nasal sprays to boost the immune system. I have yet to try these myself, but have seen them recommended on COVID-19 Safety Twitter and by cautious friends. The basic idea of these nasal sprays is to kill viruses in one’s upper respiratory tract, essentially blocking any coronavirus that might be present from spreading further. People take these sprays as a preventative measure before potential exposures.

    A couple of references on nasal sprays:

    https://twitter.com/Clean_Air_Club_/status/1685790242681331713

  • National numbers, September 10

    National numbers, September 10

    COVID-19 test positivity and viral levels in wastewater may be turning around, but hospitalizations are still going up. Chart from the CDC, data as of September 7.

    During the most recent week of data available (August 20-26), the U.S. reported about 17,400 new COVID-19 patients admitted to hospitals, according to the CDC. This amounts to:

    • An average of 2,500 new admissions each day
    • 5.3 total admissions for every 100,000 Americans
    • 16% more new admissions than the prior week (August 13-19)

    Additionally, the U.S. reported:

    • 13.5% of tests in the CDC’s surveillance network came back positive
    • A 0.3% higher concentration of SARS-CoV-2 in wastewater than last week (as of September 6, per Biobot’s dashboard)
    • 23% of new cases are caused by Omicron XBB.1.6; 22% by EG.5; 15% by FL.1.5.1 (as of September 2)

    After two months of consistent increases in major COVID-19 metrics, we have once again reached, “Has the surge peaked?” territory. Preliminary data from wastewater and testing are suggesting potential plateaus, while more people are still getting hospitalized with COVID-19.

    National trends from Biobot Analytics’ wastewater surveillance network show very similar coronavirus levels in sewage this week and last week: 641 virus copies per milliliter of sewage on September 6, compared to 639 on August 30. These data are preliminary, though, and could change as more sewersheds report.

    Biobot’s regional data suggest different trends in different parts of the country: the South and West coast might be turning around, the Northeast is still reporting an increase (but the speed of increase there is slowing), and the Midwest is reporting a sharp increase following a recent decrease.

    Data from the CDC network and WastewaterSCAN similarly show mixed results depending on your location. Among CDC sites with recent data, about half reported increased coronavirus in their wastewater in the last two weeks, while the other half reported decreases. WastewaterSCAN’s network reports continued increases in Midwestern states, including sewersheds in Michigan, Ohio, and Kansas.

    Test positivity data from the CDC’s respiratory surveillance network also indicate that the summer surge might have peaked, or at least might be slowing. For the first time in several weeks, test positivity decreased slightly in the most recent CDC update, from 14.1% in the week ending August 26 to 13.5% in the week ending September 2.

    Walgreens’ COVID-19 positivity tracker (which shares data from tests conducted by the pharmacy network) reported a slight decrease as well, from 43.6% in the week ending August 26 to 40.6% in the week ending September 2. Like the wastewater surveillance data, this information is preliminary but could be a good sign.

    Meanwhile, COVID-19 hospitalizations—a more delayed metric—are still increasing. About 2,500 people were newly hospitalized with COVID-19 each day in the week ending August 26. Hospitalizations have particularly gone up for older adults, according to data from insurance company Humana shared with STAT News.

    Many students went back to school last week, as the fall semester gets underway. This could be another driver of COVID-19 spread, as travel and gatherings were in the summer. Better air quality, masks, and other measures could make schools safer for students, teachers, staff, and their families.

    more national numbers

  • Sources and updates, August 6

    • Novavax vaccine safety: This week, the CDC published new data in its Morbidity and Mortality Weekly Report (MMWR) affirming the safety of Novavax’s COVID-19 vaccine. Unlike the Pfizer and Moderna vaccines (which use the virus’ genetic information), the Novavax vaccine works by inserting direct copies of the coronavirus spike protein into the body. It was authorized in summer 2022 as a primary series or booster for people who may be unable or unwilling to receive an mRNA vaccine. The CDC found that, among 70,000 Novavax vaccine doses administered between July 2022 and March 2023, no new safety concerns emerged.
    • Insurance coverage for COVID-19 tests: Insurance companies have covered COVID-19 tests very unevenly since the federal health emergency ended this spring. But that could change, if an advisory panel called the U.S. Preventive Services Task Force recommends that the federal government require insurers to cover COVID-19 testing. The panel is exploring this option, reports Sarah Owermohle at STAT News, though it could face legal challenges.
    • Breath test for COVID-19: A couple of weeks ago, I shared a new tool for detecting SARS-CoV-2 particles in the air, developed by researchers at Washington University in St. Louis. The same team has just published another paper, in ACS Sensors, about a similar tool that can diagnose a coronavirus infection using a patient’s breath. This breath test can detect the virus with as few as two breaths and in under 60 seconds, and is close in accuracy to a PCR test. The research team is working to continue testing this device and potentially manufacture it more broadly, according to a press release.
    • COVID-19 spread among white-tailed deer: A recent paper in Nature Communications describes how SARS-CoV-2 has circulated widely among white-tailed deer across the U.S. The research team (which includes scienitsts at the CDC, U.S. Department of Agriculture, and the University of Missouri) collected about 9,000 respiratory samples from deer in 26 states and Washington D.C. between fall 2021 and spring 2022. Hundreds of the samples were positive for SARS-CoV-2, leading the team to study genetic sequences and study how the virus had evolved in this population. The team’s full data are available online. (H/t Data Is Plural.)

  • COVID source shout-out: Free PCR tests from Walgreens

    In May 2023, the Department of Health and Human Services (HHS), Walgreens, and Labcorp started offering free PCR tests at select pharmacy locations. The program appears to still be available following the end of the federal public health emergency.

    Through the program, Americans can pick up a free kit to take a PCR test at home, then ship their sample to Labcorp for analysis. No insurance information is required. Results should be available within two days of the lab receiving the patient’s sample, according to Walgreens. About 1,000 Walgreens locations across the country are stocking these free tests, but they need to be picked up in person.

    I learned about this Walgreens program from the People’s CDC, which included it in their Weather Report newsletter on July 10. The newsletter suggests this program is recent, though I haven’t been able to find any other news about it besides a press release from May 2022. So, either tests are still available from the original iteration of the program or Walgreens revamped it recently.

    Either way, this Walgreens program is a helpful option for anyone looking to get a free PCR test—though it’s obviously far below the extensive, accessible PCR testing network that the U.S. continues to need. If any readers try this out, I would be curious to learn about your experience!

    more source spotlights

  • Sources and updates, July 16

    • Real-time detection of coronavirus in the air: A new study, published this week in Nature Communications, describes a tool to detect airborne SARS-CoV-2 particles. Researchers at Washington University in St. Louis developed this tool; it works by collecting aerosols in a container and screening them for chemical properties matching the coronavirus spike protein. In the researcher’s proof-of-concept study, the detector tool was able to detect coronavirus particles with 77% to 83% accuracy, and could detect the virus when it was present at relatively small volumes. If the tool holds up to further tests, it could be valuable for monitoring healthcare settings and other public places.
    • Routine respiratory virus testing at K-12 schools: Another study about testing, published in the CDC’s Morbidity and Mortality Weekly Report: researchers in Kansas City, Missouri regularly tested students and staff members at the public school district for SARS-CoV-2, the flu, RSV, and several other common respiratory viruses. About 900 participants opted into monthly testing for the 2022-23 school year, for a total of 3,200 tests conducted. Overall, about one in four tests were positive for at least one respiratory virus. Pre-K students had the highest positivity rate (40%), while rhinovirus/enterovirus was most commonly detected. The study shows how many viruses are going around in school settings, as well as the potential value of testing for reducing spread.
    • Predicting COVID-19 activity with Google searches: COVID-19 data commentators have long suspected that online trends indicating people were losing their sense of smell or taste in large numbers could predict an upcoming surge. (Remember the Yankee Candle Index?) Well, a new study in the CDC’s Emerging Infectious Diseases journal provides some evidence for this pattern. Researchers at Yale and Columbia Universities compared Google search trends for “loss of smell” and “loss of taste” to COVID-19 hospitalization and death numbers in five countries. They found a strong correlation between these searches and COVID-19 increases for major COVID-19 waves. So, even as official data become less available, online trends may still be a good indicator.
    • Estimating infection rates from mortality data: COVID-19 mortality data can be used to work backward and estimate true infection rates, according to a new paper in Science by researchers at the University of California Davis and the University of the Basque Country (in Spain). The scientists used a machine learning model to analyze death reports from several European countries, essentially predicting infection rates in reverse. Their analysis found that lockdowns and mask requirements, among other COVID-19 safety measures, had a major impact on transmission, one of the authors said in a press release. Mortality data continues to present a useful tool for tracking COVID-19’s full impact.
    • Long COVID cohort study suggests full recovery may be rare: One more notable new study, shared by The Lancet as a preprint: researchers at a hospital in Barcelona shared the results of a study following Long COVID patients for two years. The study followed 548 people, including 341 with Long COVID and 207 who did not have long-term symptoms after acute COVID-19. Only 26 (7.6%) of the Long COVID patients recovered during the two-year follow-up period, according to symptom surveys and diagnostic testing. Hannah Davis, a patient-researcher at the Patient-Led Research Collaborative, shared additional highlights and takeaways from the study in a Twitter thread.
    • New bill to strengthen wastewater surveillance: Finally, a bit of hopeful news: three U.S. senators just introduced a bipartisan bill that would strengthen the CDC’s National Wastewater Surveillance System (NWSS). The bill would specifically expand NWSS to include surveillance for other public health threats, and would enable it to provide more funding to state and local health agencies. Cory Booker from New Jersey, Angus King from Maine, and Mitt Romney from Utah are the three sponsors. I’m not a political reporter, so I won’t pretend to know how likely this bill’s chances are of passing, but I hope it’s a step toward making the U.S.’s wastewater surveillance infrastructure permanent.

    Editor’s note, July 23, 2023: An earlier version of this post misstated the virus most commonly detected in the Kansas City schools study. (It was rhinovirus/enterovirus, not RSV.)

  • National numbers, June 18

    National numbers, June 18

    COVID-19 hospital admissions and test positivity (from a select number of labs) are both trending slightly down. Chart from the CDC.

    In the past week (June 4 through 10), the U.S. reported about 6,600 new COVID-19 patients admitted to hospitals, according to the CDC. This amounts to:

    • An average of 950 new admissions each day
    • 2.0 total admissions for every 100,000 Americans
    • 8% fewer new admissions than last week (May 28-June 3)

    Additionally, the U.S. reported:

    • 4.0% of tests in the CDC’s surveillance network came back positive (a 5% decrease from last week)
    • A 5% lower concentration of SARS-CoV-2 in wastewater than last week (as of June 14, per Biobot’s dashboard)
    • 40% of new cases are caused by Omicron XBB.1.5; 26% by XBB.1.16; 21% by XBB.1.9 (as of June 10)

    Overall, the national COVID-19 picture remains fairly similar to what we’ve seen for the last few weeks. The U.S. is at a plateau of COVID-19 spread; we could see an increase this summer, but limited data make it hard to say for sure.

    New hospitalizations for COVID-19 continue to trend slightly down, with just under 1,000 patients admitted each day nationwide. This is the first time that the U.S. has passed this low benchmark since early in the pandemic, and suggests the protective value of vaccinations and prior infections for preventing severe symptoms.

    Biobot Analytics resolved the data issue I mentioned last week and provided updated wastewater numbers, also showing a continued (though slight) downward trend. Current national coronavirus levels are far below this time last year, when Omicron BA.2 variants were spreading widely, though they’re still above prior low points in 2020 and 2021.

    Biobot’s regional data also show mostly plateaus, though coronavirus levels may be increasing very slightly in the Northeast. The CDC’s wastewater data also suggest some places in the Northeast may be seeing increased viral spread, but it’s difficult to identify a clear regional trend.

    Trends from the CDC’s lab testing network similarly show a potential increase in COVID-19 spread in the Northeast over the last couple of weeks, though this testing trend has yet to translate to higher hospitalizations. In New York City, some of the sewersheds that reported recent coronavirus upticks now appear to be trending back down.

    Is a summer surge coming for the Northeast, and then the rest of the country? Right now, it’s quite hard to say; signals from wastewater and testing data are mixed, sometimes delayed, and tough to interpret in the short term. I’ll be watching closely to see how this changes in the coming weeks.

    Meanwhile, it’s important to remember that data are especially limited when it comes to Long COVID, one of the most severe (and most likely) impacts of coronavirus infection. As testing becomes less and less accessible, fewer people will recognize their infections—and, as a result, they may be less likely to recognize later symptoms as Long COVID. But those symptoms can still occur, and cause lasting damage.

    more national numbers
  • National numbers, June 4

    National numbers, June 4

    Both hospital admissions and test positivity for COVID-19 have ticked down in recent weeks. Chart via the CDC.

    In the past week (May 21 through 27), the U.S. reported about 7,600 new COVID-19 patients admitted to hospitals, according to the CDC. This amounts to:

    • An average of 1,100 new admissions each day
    • 2.3 total admissions for every 100,000 Americans
    • 8% fewer new admissions than last week (May 14-20)

    Additionally, the U.S. reported:

    • 4.4% of tests in the CDC’s surveillance network came back positive (a 0% change from last week)
    • A 17% lower concentration of SARS-CoV-2 in wastewater than last week (as of May 31, per Biobot’s dashboard)
    • 54% of new cases are caused by Omicron XBB.1.5; 19% by XBB.1.16; 18% by XBB.1.9 (as of May 27)

    The COVID-19 plateau of the last few weeks continues at the national level, though experts are concerned that a summer surge could occur in parts of the country. Wastewater surveillance and testing data are indicating potential increases in the New York City region.

    Hospital admissions for COVID-19 remain at the levels we’ve seen throughout the spring, with about 1,100 people admitted nationwide each day last week. These numbers are similar to the hospitalizations reported at previous low points for COVID-19, in spring 2022 and 2021.

    Testing data from the CDC’s National Respiratory and Enteric Virus Surveillance System (NREVSS) also suggest a plateau: national test positivity didn’t change from last week to this week. While this CDC system includes a small fraction of the PCR labs that reported COVID-19 tests before the federal emergency ended, it’s still a helpful indicator for testing trends.

    Wastewater surveillance data from Biobot shows a similar picture, with coronavirus levels in sewage remaining consistent at the national level for the last two months. All four major regions of the country are trending down, according to Biobot’s analysis.

    But national data can hide more concerning trends at the local level. Wastewater data from New York City’s fourteen water treatment plants suggest potential increases in COVID-19 spread in the city and outlying suburbs over the last couple of weeks. The city’s wastewater data are reported with a delay (as of today, the most recent update was May 21), so I find it worrying that an increase may have predated the Memorial Day holiday. Test positivity data for the New York/New Jersey region suggest an uptick as well.

    NYC has been a bellwether for the rest of the U.S. at many points during the pandemic, and it’s possible that the city could see a surge before other regions again this summer. Health experts are also closely watching the South, where people gather indoors more in the summer.

    About 96% of Americans over age 16 have some COVID-19 protection from vaccination, past infections, or both, according to a recent CDC study. This protection will help many people avoid severe COVID-19 symptoms this summer even if they get infected. But Long COVID continues to be a risk—potentially even escalating with more infections.

    more national numbers

  • Answering reader questions about wastewater data, rapid tests, Paxlovid

    I wanted to highlight a couple of questions (and comments) that I’ve received recently from readers, hoping that they will be useful for others.

    Interpreting wastewater surveillance data

    One reader asked about how to interpret wastewater surveillance data, specifically looking at a California county on the WastewaterSCAN dashboard. She noticed that the dashboard includes both line charts (showing coronavirus trends over time) and heat maps (showing coronavirus levels), and asked: “I’m wondering what the difference is, and which is most relevant to following actual infection rates and trends?”

    My response: Wastewater data can be messy because environmental factors can interfere with the results, and what may appear to be a trend may quickly change or reverse course (this FiveThirtyEight article I wrote last spring on the topic continues to be relevant). So a lot of dashboards use some kind of “risk level” metric in addition to showing linear trends in order to give users something a bit easier to interpret. See the “virus levels” categories on the CDC dashboard, for instance.

    Personally, I like to look at trends over time to see if there might be an uptick in a particular location that I should worry about, but I find the risk level metrics to be more useful for actually following infection rates. Of course, every dashboard has its own process for calculating these levels—and we don’t yet have a good understanding of how wastewater data actually correlate to true community infections—so it’s helpful to also check out other metrics, like hospitalizations in your county.

    Rapid test accuracy

    Another reader asked: “Is there any data on the effectiveness of rapid tests for current variants like Arcturus? I’m hearing more and more that they are working less and less well as COVID evolves.”

    My response: Unfortunately, I’m not aware of any specific data on rapid test effectiveness for recent variants. Early in the Omicron period, there were a few studies that showed the rapid tests still worked for that variant. The virus has obviously evolved a lot since then, but there is less interest in and fewer resources for evaluating these questions at this point in the pandemic, so it’s hard to say whether the continued mutations have had a significant impact on test effectiveness.

    I think it’s important to flag, though, that rapid tests have never been highly accurate. People have tested negative on rapids—only to get a positive PCR the next day—since these tests were first introduced in spring 2021. The tests can be helpful for identifying if someone is contagious, with a high viral load, but are less accurate for people without symptoms. So, my recommendation with these tests is always to test multiple times, and to get a PCR if you have access to that. (Acknowledging there is less and less PCR access these days.) Also, if you were recently exposed to COVID-19, wait a few days to start rapid testing; see more details in this post from last year.

    Double dose of Paxlovid

    Another reader wrote in to share their experience with accessing Paxlovid during a recent COVID-19 case. The reader received a Paxlovid prescription, which led to a serious alleviation of symptoms. But when she experienced a rebound of symptoms after finishing the Paxlovid course, she had a hard time getting a second prescription.

    “Fauci, Biden, head of Pfizer and CDC director got a second course of Paxlovid prescribed to them,” the reader wrote. “When I attempted to get this, my doctors pretended I was crazy and said this was never done.” She added that she’d like to publicize the two-course Paxlovid option.

    My response: I appreciate this reader sharing her experience, and I hope others can consider getting multiple Paxlovid prescriptions for a COVID-19 case. The FDA just provided full approval to Pfizer for the drug, which should alleviate some bureaucratic hurdles to access. I also know that current clinical trials testing Paxlovid as a potential Long COVID treatment are using a longer course; 15 days rather than five days. The results of those trials may provide some evidence to support a longer course overall.

    If you have a COVID-19 question, please send me an email and I’ll respond in a future issue!

  • The federal public health emergency ends next week: What you should know

    The federal public health emergency ends next week: What you should know

    A chart from the CDC’s recent report on surveillance changes tied to the end of the federal public health emergency.

    We’re now less than one week out from May 11, when the federal public health emergency (or PHE) for COVID-19 will end. While this change doesn’t actually signify that COVID-19 is no longer worth worrying about, it marks a major shift in how U.S. governments will respond to the ongoing pandemic, including how the disease is tracked and what public services are available.

    I’ve been writing about this a lot in the last couple of months, cataloging different aspects of the federal emergency’s end. But I thought it might be helpful for readers if I compiled all the key information in one place. This post also includes a few new insights about how COVID-19 surveillance will change after May 11, citing the latest CDC reports.

    What will change overall when the PHE ends?

    The ending of the PHE will lead to COVID-19 tests, treatments, vaccines, and data becoming less widely available across the U.S. It may also have broader implications for healthcare, with telehealth policies shifting, people getting kicked off of Medicaid, and other changes.

    Last week, I attended a webinar about these changes hosted by the New York City Pandemic Response Institute. The webinar’s moderator, City University of New York professor Bruce Y. Lee, kicked it off with a succinct list of direct and indirect impacts of the PHE’s end. These were his main points:

    • Free COVID-19 vaccines, tests, and treatments will run out after the federal government’s supplies are exhausted. (Health experts project that this will likely happen sometime in fall 2023.) At that point, these services will get more expensive and harder to access as they transition to private healthcare markets.
    • We will have fewer COVID-19 metrics (and less complete data) to rely on as the CDC and other public health agencies change their surveillance practices. More on this below.
    • Many vaccination requirements are being lifted. This applies to federal government mandates as well as many from state/local governments and individual businesses.
    • The FDA will phase out its Emergency Use Authorizations (EUAs) for COVID-19 products, encouraging manufacturers to apply for full approval. (This doesn’t mean we’ll suddenly stop being able to buy at-home tests—there’s going to be a long transition process.)
    • Healthcare worker shortages may get worse. During the pandemic emergency, some shifts to work requirements allowed facilities to hire more people, more easily; as these policies are phased out, some places may lose those workers.
    • Millions of people will lose access to Medicaid. A federal rule tied to the PHE forbade states from kicking people off this public insurance program during the pandemic, leading to record coverage. Now, states are reevaluating who is eligible. (This process actually started in April, before the official PHE end.)
    • Telehealth options may become less available. As with healthcare hiring, policies during the PHE made it easier for doctors to provide virtual care options, like video-call appointments and remote prescriptions. Some of these COVID-era rules will be rolled back, while others may become permanent.
    • People with Long COVID will be further left behind, as the PHE’s end leads many people to distance themselves even more from the pandemic—even though long-haulers desperately need support. This will also affect people who are at high risk for COVID-19 and continue to take safety precautions.
    • Pandemic research and response efforts may be neglected. Lee referenced the “panic and neglect” cycle for public health funding: a pattern in which governments provide resources when a crisis happens, but then fail to follow through during less dire periods. The PHE’s end will likely lead us (further) into the “neglect” part of this cycle.

    How will COVID-19 data reporting change?

    The CDC published two reports this week that summarize how national COVID-19 data reporting will change after May 11. One goes over the surveillance systems that the CDC will use after the PHE ends, while the other discusses how different COVID-19 metrics correlate with each other.

    A lot of the information isn’t new, such as the phasing out of Community Level metrics for counties (which I covered last week). But it’s helpful to have all the details in one place. Here are a few things that stuck out to me:

    • Hospital admissions will be the CDC’s primary metric for tracking trends in COVID-19 spread rather than cases. While more reliable than case counts, hospitalizations are a lagging metric—it takes typically days (or weeks) after infections go up for the increase to show up at hospitals, since people don’t seek medical care immediately. The CDC will recieve reports from hospitals at a weekly cadence, rather than daily, after May 11, likely increasing this lag and making it harder for health officials to spot new surges.
    • National case counts will no longer be available as PCR labs will no longer be required to report their data to the CDC. PCR test totals and test positivity rates will also disappear for the same reason, as will the Community Levels that were determined partially by cases. The CDC will also stop reporting real(ish)-time counts of COVID-associated deaths, relying instead on death certificates.
    • Deaths will be the primary metric for tracking how hard COVID-19 is hitting the U.S. The CDC will get this information from death certificates via the National Vital Statistics System. While deaths are reported with a significant lag (at least two weeks), the agency has made a lot of progress on modernizing this reporting system during the pandemic. (See this December 2021 post for more details.)
    • The CDC will utilize sentinel networks and electronic health records to gain more information about COVID-19 spread. This includes the National Respiratory and Enteric Virus Surveillance System, a network of about 450 laboratories that submit testing data to the CDC (previously established for other endemic diseases like RSV and norovirus). It also includes the National Syndromic Surveillance Program, a network of 6,300 hospitals that submit patient data to the agency.
    • Variant surveillance will continue, using a combination of PCR samples and wastewater data. The CDC’s access to PCR swab samples will be seriously diminished after May 11, so it will have to work with public health labs to develop national estimates from the available samples. Wastewater will help fill in these gaps; a few wastewater testing sites already send the CDC variant data. And the CDC will continue offering tests to international travelers entering the country, for a window into global variant patterns.
    • The CDC will continue tracking vaccinations, vaccine effectiveness, and vaccine safety. Vaccinations are generally tracked at the state level (every state health agency, and several large cities, have their own immunization data systems), but state agencies have established data sharing agreements with the CDC that are set to continue past May 11. The CDC will keep using its established systems for evaluating how well the vaccines work and tracking potential safety issues as well.
    • Long COVID notably is not mentioned in the CDC’s reports. The agency hasn’t put much focus on tracking long-term symptoms during the first three years of the pandemic, and it appears this will continue—even though Long COVID is a severe outcome of COVID-19, just like hospitalization or death. A lack of focus on tracking Long COVID will make it easier for the CDC and other institutions to keep minimizing this condition.

    On May 11, the CDC plans to relaunch its COVID-19 tracker to incorporate all of these changes. The MMWR on surveillance changes includes a list of major pages that will shift or be discontinued at this time.

    Overall, the CDC will start tracking COVID-19 similar to the way it tracks other endemic diseases. Rather than attempting to count every case, it will focus on certain severe outcomes (i.e., hospitalizations and deaths) and extrapolate national patterns from a subset of healthcare facilities with easier-to-manage data practices. The main exception, I think, will be a focus on tracking potential new variants, since the coronavirus is mutating faster and more aggressively than other viruses like the flu.

    What should I do to prepare for May 11?

    If you’ve read this far, you’re probably concerned about how all these shifts will impact your ability to stay safe from COVID-19. Unfortunately, the CDC, like many other public agencies, is basically leaving Americans to fend for themselves with relatively little information or guidance.

    But a lot of information sources (like this publication) are going to continue. Here are a few things I recommend doing this week as the PHE ends:

    • Look at your state and local public health agencies to see how they’re responding to the federal shift. Some COVID-19 dashboards are getting discontinued, but many are sticking around; your local agency will likely have information that’s more tailored to you than what the CDC can offer.
    • Find your nearest wastewater data source. With case counts basically going away, wastewater surveillance will be our best source for early warnings about surges. You can check the COVID-19 Data Dispatch list of wastewater dashboards and/or the COVIDPoops dashboard for sources near you.
    • Stock up on at-home tests and masks. This is your last week to order free at-home/rapid tests from your insurance company if you have private insurance. It’s also a good time to buy tests and masks; many distributors are having sales right now.
    • Figure out where you might get a PCR test and/or Paxlovid if needed. These services will be harder to access after May 11; if you do some logistical legwork now, you may be more prepared for when you or someone close to you gets sick. The People’s CDC has some information and links about this.
    • Contact your insurance company to find out how their COVID-19 coverage policies are changing, if you have private insurance. Folks on Medicare and Medicaid: this Kaiser Family Foundation article has more details about changes for you.
    • Ask people in your community how you can help. This is a confusing and isolating time for many Americans, especially people at higher risk for COVID-19. Reaching out to others and offering some info or resources (maybe even sharing this post!) could potentially go a long way.

    That was a lot of information packed into one post. If you have questions about the ending PHE (or if I missed any important details), please email me or leave a comment below—and I’ll try to answer in next week’s issue.

    More about federal data

  • National numbers, April 30

    National numbers, April 30

    The number of COVID-19 tests reported to the CDC has declined precipitously since peak COVID-19 surges, even though COVID-19 spread has not. Chart from the CDC.

    In the past week (April 20 through 26), the U.S. officially reported about 88,000 new COVID-19 cases, according to the CDC. This amounts to:

    • An average of 13,000 new cases each day
    • 10% fewer new cases than last week (April 13-19)

    In the past week, the U.S. also reported about 11,000 new COVID-19 patients admitted to hospitals. This amounts to:

    • An average of 1,500 new admissions each day
    • 3.2 total admissions for every 100,000 Americans
    • 16% fewer new admissions than last week

    Additionally, the U.S. reported:

    • 1,100 new COVID-19 deaths (150 per day)
    • 69% of new cases are caused by Omicron XBB.1.5; 13% by XBB.1.9; 12% by XBB.1.16 (as of April 29)
    • An average of 40,000 vaccinations per day

    Major COVID-19 metrics continue to suggest an ongoing (though slight) decline in the virus’ spread nationally, despite the rise of newer and more contagious variants. The moderate plateau persists.

    Officially-reported cases and new hospital admissions declined by 10% and 16% respectively last week, compared to the week prior. According to the CDC’s data notes, three states (Florida, Iowa, and Pennsylvania) did not report cases last week, while two states (Louisiana and Indiana) reported extra cases from their historical backlogs.

    In addition to the ongoing reporting issues from state health departments, it’s important to remember that PCR testing continues to decline across the country. About one million PCR and similar lab test results were reported to the CDC last week, compared to peaks over 10 million per week during major surges.

    Still, the hospitalization numbers and wastewater surveillance data lead me to suggest that we really are in a transmission plateau. Wastewater data from Biobot show a slight decline in national coronavirus concentrations over the last month.

    All four regions of the country are also experiencing COVID-19 plateaus, according to Biobot’s data. The West Coast and Midwest have slightly higher coronavirus levels than the Northeast and South, but there aren’t huge differences between the regions.

    The West and Midwest are also hotspots for XBB.1.16 and XBB.1.9, the two Omicron subvariants that have started competing with XBB.1.5 over the last few weeks. This competition is happening slowly; XBB.1.5 declined from an estimated 84% of new cases during the last week of March to 69% of new cases this past week, according to the CDC’s estimates.

    At this point, it’s hard to tell how much of an impact the latest variants will have on overall COVID-19 spread. And these connections likely will only get more difficult to parse out, as PCR testing continues to decline and reporting gets less reliable. The CDC itself is currently evaluating how to adjust its data-sharing practices when the federal public health emergency ends on May 11.

    more national numbers