4-1/ My COVID update for epidemiological weeks 3-4 of 2025.
For the 1st time since 1952, the CDC stopped publishing its Morbidity and Mortality Weekly Report (MMRW)—the last update was on 16 Jan. Is the Trump administration emulating Chinese secrecy practices?
4-2/ Other CDC data pages seem to be up and running, though. Their wastewater numbers seem to indicate the current XEC COVID wave has peaked. Biobot hasn't published an update recently, so I don't have a reality check for CDC's data.
4-3/ Biofire's proprietary Syndromic Trends also shows COVID dropping off as a percentage of detected respiratory viruses. RSV may also be on downward curve, but influenza is rising fast.
C4-4/ As of last week, COVID was 6.2% of positive tests, while RSV was 8.8%, and Influenza at 25% (!). Likewise, Flu is at 5.2% of ED visits, while COVID is 0.9% and RSV is 0.6%.
4-5/ COVID hospitalizations are lower than previous years—and about half of what last winter's were (4/100,000 vs 7.7/100,000). Despite the XEC wave, weekly deaths remain low. Not sure if we'll continue to see these numbers now that the MMWR reports have stopped.
4-6/ It's very likely that we are past the peak of the current COVID wave. XEC seems to have lost steam. Cov-Spectrum shows it topping out at 41% of sequences. The CDC Nowcast shows it at ~47%, but their Nowcast isn't very sensitive to changes in growth rates.
4-7/ What's next? LP.8.1 is the only major var that's showing any legs. But except in countries with low sampling rates, it hasn't gotten much above 20%. Maybe it will create a secondary wavelet on the tail end of our dinky winter wave, but I doubt it.
4-8/ While COVID and RSV may have peaked, this winter's Influenza wave is still growing.
4-9/ Over on bsky, Marc Johnson (@SolidEvidence on X and bsky) calculates that between 0.25-0.5% of ww samples are from persistent infections. I'd be curious what percentage of these peeps are suffering from Long COVID or are asymptomatic.
4-10/ In HPAI news, 3 days before Trump's inauguration, Biden awarded Moderna $590 million to develop mRNA-based pandemic vaccines. It's not clear if the Trump administration will try to cancel this grant.
4-11/ Finally, there are rumors that human-to-human transmission of HPAI has been happening in Shanxi and Hebei provinces (northern China) w/ deaths in the hundreds. Rumors only. Other rumors say this is an HMPV outbreak. I'm sure Bhatty and Brainworm are on it. #snarkasm
4-12/ That's it for now. See you in two epi weeks.
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38-1/ My pathogen update for epidemiological weeks 35-38. All COVID this update.
Biobot's wastewater numbers and the CDC's NWSS seem to both indicate that the current wave has peaked. Of course, I thought that was the case 4 weeks ago, but the numbers spiked up again.
38-2/ Notice that the CDC's NWSS data shows the current wave is nearly as high as our 2024-25 winter wave. I suspect that's because they're normalizing their data against the previous year's numbers. OTOH, ED visits are higher for this wave than the previous one...
38-3/ If Biobot's CpmL/PMMOV numbers are a better indicator of transmission than NWSS data, I'd have to conclude that XFG.x variant is more virulent than XEC.x in that there is a higher rate of ED visits this current wave. But this is not reflected in hospitalizations or deaths.
20-1/ My pathogen update for epi weeks 17-20 of 2025.
X seems to be shadow-banning my posts ever since I suggested Musk's erratic behavior was due to his ketamine abuse. Oh well. I'll continue to post here. Let me know if you're seeing them. On to the update...
20-2/ US SARS2 wastewater concentrations have dropped to the lowest interwave levels since June 2021. They haven't dropped to June '21 levels yet, but they're continuing to fall everywhere except the West—but the West is at lower levels than the previous two interwave gaps.
20-3/ As of the beginning of May COVID hospitalization rates were the lowest they've been since the start of the pandemic. But SARS-CoV-2 is still circulating. Patients are still testing positive for COVID, while the positivity rates for influenza and RSV have fallen.
16-1/ My pathogen update for epi weeks 15-16 of 2025.
Per Biobot, national SARS2 wastewater concentrations as of 12 April were almost down to the levels of post-Omicron interwave gaps. I suspect they're there now.
16-2/ If patterns hold, SARS2 should maintain this low level of circulation for a few weeks before climbing again in an upward curve. Though previous summer peaks have been late Aug/early Sept, I wouldn't be surprised to see the next wave peak in July or early Aug. We'll see.
16-3/If the trends hold, COVID-19 weekly mortality rates and ED visits will drop below levels of previous interwave gaps in the next few weeks. COVID-19 is still holding on to 14th place as most common cause of death, but I wonder if it won't drop off the top 15 by the end of 25.
14-1/ My pathogen update for epi weeks 13-14 of 2025.
As of 28 March, we're not down to previous interwave SARS2 circulation levels yet—except for the Western region of the US. But the rest of the US should be there by the 3rd week of April.
14-2/ COVID hospitalizations, ED visits, and deaths all tracking downward as of two weeks ago.
14-3/ Flu season is receding as well. As with most previous seasons, we've got a long tail of influenza B cases, but they're nowhere near the numbers of influenza A cases.
12-1/ My pathogen update for epi weeks 11-12 of 2025. The XEC COVID wave hasn't fully receded yet. Biobot shows that as of March 15, SARS2 wastewater levels haven't fallen to previous interwave gaps except for the Western region of the US.
12-2/ The CDC's ww numbers indicate a long tail for this wave, but it shows the West and NE back to interwave levels. These numbers are all normalized to the previous year's numbers, so I don't know if this long tail may be an artifact of the way they normalize. I trust Biobot.
12-3/ If there is a long tail, it's due to the LP.8.1x brood that continues to gain traction against XEC.x. I expected the LP.8.1x's to top out at about 30%, but CoV-Spectrum shows they've reached 50%. O/c, there were only 3 LP.8.1x descendants a month ago. Now there are 19.
10-1/ My pathogen update for epi weeks 9-10 of 2025. I'm renaming this a "pathogen update" because SARS-CoV-2 is fading into endemicity. That doesn't mean that COVID-19 won't remain a public health problem, but we've got a bunch of other pathogens that we need to keep our eye on.
10-2/ But speaking of COVID-19, the current wave is receding. Both the CDC's wastewater activity levels and Biobot's wastewater concentration chart show a downward trend in all regions of the US,
10-3/ This XEC wave had the lowest rates of hospitalizations, ED visits, and deaths of any variant wave so far (at least for the US). And rates of test positivity for RSV and Influenza outpaced COVID this respiratory season.