Thread by @EricTopol

We've learned a lot about Prior Covid ("Natural Immunity") over the past year, but the US/CDC continues to negate the abundant evidence for it providing any protection
erictopol.substack.com/p/ground-truth… w/links
And there's substantial new data, I'll review🧵here /1

Last week, the large J&J 1- shot, placebo-controlled trial w/ >2,000 participants who had Prior Covid published @NEJM
Vaccine effectiveness vs moderate/severe disease
Prior Covid 90%
J&J Vaccine 56%
Yet 1-shot J&J vaccine = "fully vaccinated" @CDCgov
Nothing for Prior Covid /2

Neutralizing antibodies after Prior Covid are present out to 16 months in 214 people (graph)
And another study showing persistence of memory B cells at 15 months /3

Over 7,000 UK health care workers with Prior Covid and assessment of IgG antibodies that were anticipated to last 1.5 to 2 years /4

The January 2022 CDC MMWR for California and New York State showed remarkable protection of Prior Covid, unvaccinated vs hospitalization, during the Delta wave /5

The new UK study, November 2021 to January 2022, the largest comparison of Omicron and Delta for hospitalizations and deaths, among 1.5 M people
Prior Covid, unvaccinated, hazard ratio, 95% CI
Hospitalization 0.55 (0.45, 0.63)
Death 0.18 (0.06, 0.57) /6

The protection afforded by Prior Covid was substantially reduced with Omicron, as evidenced by the jump in reinfection in the UK (previously quite rare) /7

And the drop in vaccine effectiveness vs symptomatic infection in Qatar, as published this week, from ~90% (prior variants) to 56% (Omicron) /8

All studies for Prior Covid have issues w/r to survival bias (people who died not included), heterogeneity of antibody,cellular immune response levels and their durability.
Getting Covid obviously doesn't protect #LongCovid, unlike vaccines which have shown protective benefit /9

There is unequivocal synergy of hybrid immunity (combined Prior Covid and 1 or more vaccine doses) in more than 25 studies pre-Omicron, and several with Omicron, for the augmented immune response /10

The CDC should reboot its "vaccination card" to a digital "immunity certificate" and give credit to confirmed Prior Covid, that is equivalent to at least a 1-dose vaccine /11

Vaccine mandates, without long overdue recognition of Prior Covid's protection, unnecessarily fuels divisiveness.
The US is only 64% "fully vaccinated" compared w/ many countries at 80%+. Recognition of Prior Covid can help build our immunity wall, which should be the priority

I meant to add this report (it's in the full post) from >52,000 health care workers at Cleveland Clinic health system which showed lack of symptomatic infections in the Prior Covid, unvaccinated group, at 1-year follow up, through the Delta phase