1/ Another new MMWR study cdc.gov/mmwr/volumes/7… reporting on the seroprevalence of C19 infections during Omicron. As usual, there is some good data here to promote our understanding, but then auths opine on an UNRELATED yet CRUCIAL narrative. 🧵👇 2a/ The study focuses on the period of 9/21-2/22, recording the %% of participants with anti-N antibodies – Abs only triggered by natural infection, NOT vaccination. The results are given over time, and stratified by age group.

1a/ 🚩UPDATE: Last week, I posted a critique

https://twitter.com/mahesh_shenai/status/1517551215067992064

of the CDC/MMWR study: cdc.gov/mmwr/volumes/7…. One of my points (4b) highlighted the misleading claim that “9 in 10” hosp. children were unvaxed. I made an inquiry to the MMWR, and got a response. 🧵👇 1b/ Bottom line – they present technically true statistics taken out of context, and produce simplified graphics that are easily amplified in social media, without scrutiny. However, we NEED to scrutinize!

1a/ CDC/MMWR cdc.gov/mmwr/volumes/7… report just published, claiming C19/Omi hosp. in 5-11yo were 2x more likely in the unvaxed, and 9/10 hosp. were unvaxed. With MMWR, toplines & graphics are selected for a predetermined narrative. Appraisal & perspective required. 🧵👇 1b/ I will appraise the most critical, related to their claims on vaccination.
[1] That hospitalizations were 2x more likely in the UV, and
[2] 9/10 hospitalizations were in the UV.

(UV=unvaxed, V=vax)

1/ 🚩🚨🚩cdc.gov/mmwr/volumes/7… Surprising paper in MMWR: C19 Cases and Hospitalizations in vaxed AND previous infected. Explicitly concludes “By early October, persons who survived a previous infection had LOWER case rates than persons who were vaccinated alone!” Finally! 🧵👇 2a/ Paper reports on populations in California and NY, in 1.1 M total cases. They divided the population into four groups:

No prior infection/Unvaxed (NPI/UV)
No prior infection/Vaxed (NPI/V)
Prior infection/Unvaxed (PI/UV)
Prior infection/Vaxed (PI/V)

assets.publishing.service.gov.uk/government/upl… UK HSA briefing, suggesting additional vax and booster doses on top of prior infection (PI) adds protection w/Omicron. The reporting on this study (and interpretation by some on Twitter) is one-sided. Here are my thoughts- 🧵👇 2a/ The UK HSA has been a leader in COVID data dissemination, particularly in the context of Omicron and variants of concern. They quickly aggregate the data and studies, and put out weekly analysis, which asks the pertinent questions. Their findings are credible.

1a/ medrxiv.org/content/10.110… Recent pre-print by Kaiser group, on Moderna vax effectiveness in Delta & Omi. Finds VE reduced with Omi to 30%, but “boost” can improve to 63% overall, but with minimal effect in immunocompromised. Study is Moderna sponsored, and should raise ?? 🧵👇 1b/ The analysis appears well-designed and well-conducted. The results are generally not favorable for Moderna, but since its industry-funded, there is some “spin” control going on.

1/ medrxiv.org/content/10.110… Another solid preprint study by Qatari group re: protection of PRIOR INFECTION (PI) to Omicron & other variants. Overall, PI protection reduced with Om, but extremely good vs. hosp/death, similar to vax. AND, PI+Vax does not improve protection. 🧵👇 2/ The study finds 54% protection against symptomatic infection, 87.8% against hosp/death.

PI protection vs. Omicron infxn is 56% (90% Alpha, 85% Beta, 92% Delta).

PI protection vs. Omicron hosp/death: 87.8% (69.4% Alpha, 88% Beta, 100% Delta)

1/ 🚩🚩medrxiv.org/content/10.110… New pre-print study out of UK SIREN group looking at durability of vax & prev. infxn (PI) from 3/20 - 9/21. Conclusion: Greater protection by PI vs. vax, vax wanes faster than PI, but PI may confer increased but (modest) benefit. 🧵below 2a/ This is an exceptional author group, “SIREN” , that led some of the earlier studies on NI, which found an 84% risk reduction (RR) by PI, lasting at least 7 months. Link: pubmed.ncbi.nlm.nih.gov/33844963/

1a/ cdc.gov/mmwr/volumes/7… We are all familiar with this MMWR study, citing “5.5x” increased chance of C19 reinfection vs. fully vax breakthru. Another sister MMWR paper (“IC”) released the SAME DAY, provides some unexpected perspective. 🧵🧵 below 1b/ cdc.gov/mmwr/volumes/7… SPOILER: The sister paper (“IC”) studied the SAME hosp. data in the SAME time period for different ??s, but found a general infxn rate in unvaxed of 3-5x vs. either previous infection (PI) or vaccination (FV). In other words, substantially similar!

1a/jamanetwork.com/journals/jama/… Interesting paper recently pub by JAMA. re: prior C19 in mRNA vaxed persons. This D/N compare V+PI vs. PI alone, but V+PI vs. Vax alone (a different ?). PI + Vax significantly reduced infection risk compared to mRNA Vax alone. Fascinating result in🧵👇 1b/ SPOILER: Vaxed persons with a PI had a much lower rate of infection, in both Pfizer (0.18x) and Mdrna (0.35x). But MORE INTERESTING: Those Vaxed >6m after PI did better than Vax<6 months, by a lot!
(fyi, PI= prev. inf, nPI= not PI).

1/ cdc.gov/coronavirus/20… After release of their MMWR study, CDC releases this BRIEF on Infection-induced vs. Vax-induced Immunity. It is a CONFUSED document – both accepting NI, but illogically recommending VAX anyway. This 🧵🧵 appraises the BRIEF – 2a/ It is important that the CDC get this STRAIGHT. For children 5-11 particularly, NI reduces C19 risk significantly, to the point that the vaccine offers virtually no benefit to COVID-recovered children. The ACIP meets tomorrow on this question. They NEED to address NI (PI)!

1/ 🚨🚨 cdc.gov/mmwr/volumes/7… This MMWR article is a confluence of methodological flaws, that amplify to serve the predetermined message of the CDC. This 🧵 will summarize my appraisals. 2a/ On a high-level, they utilize “adjusted” odds ratios to dramatize the result. The ACTUAL raw difference between PI and Vax is actually small: 8.7% PI vs. 5.1% Vax in HOSPITALIZED PATIENTS with C19-like symptoms. 3.6%. That is a SMALL difference in a very SPECIFIC population.

1/ IMPORTANT THREAD: @ 5-11 VRBPAC Members saw “scenario analysis” of vax BENEFIT vs RISK, by an FDA epidemiologist. The math is simple, but the scenarios considered were FLAWED & NARROW. This 🧵recreates the model w/ new and more germane scenarios. 1b/ SPOILERS FIRST:
In AVERAGE INCIDENCE SCENARIOS , vax prevents CASES in COVID-(N)aive on par with vax “related AEs”, AND serious AEs/death generally on par w/ C19 hosps saved.

fda.gov/media/153507/d…
1/ Interesting risk-benefit analysis for 5-11yos from Dr.Yang, an FDA epidemiologist, providing scenarios at VRBPAC (not Pfizer sponsored analysis). It favors the OPTION for vaccine, but argues against any MANDATE. This🧵interprets this presentation. 2/ Analysis calculates the number of Cases, Hospitalizations, ICU stays, and Deaths prevented by vax, compared to the excess of same complications by myocarditis/pericarditis. Myo/pericarditis is the only complication considered.

1/ As the @FDA decides on EUA for 5-11 yos, w/ minimal efficacy data, the most NEGLECTED subgroup are COVID-recovered 5-11yos, who have virtually no representation in any study. This THREAD attempts to quantify the benefit of vaccination in this subgroup. @noorchashm @ToddZywicki 2/ Recovered 5-11 yos have 3 coinciding reasons for minimal benefit from vax: 1) extremely low rates of symptom. morbidity, 2) adult data suggesting notable protection (70-90%) from NI alone, 3) adult data suggesting vax in recovered is 18-33%. Let us examine each: @JeanRees10