Thread by @magi_jay

Natural immunity appears to be robust in the short term, as does vaccine-induced immunity. Comparisons between these cases are of great scientific import. At this moment, tho, it is incorrect to argue the science is complete OR that natural immunity should influence public policy

An individualized approach to public health causes all kinds of issues. It’s logistically unfeasible at this scale & creates gaps. It also faciliates bad inferences, such as 1. People have reason to fear vaccines & 2. Perhaps it is preferable to become naturally immune

Note I am *not* saying, “ignore or deny the science on natural immunity.” Natural immunity & vaccine-induced immunity are both great. I am saying the incautious convo is causing more harm than benefit. Also: The differences between kinds of immunity are not “settled” science

The Israeli study has gotten a lot of attention. It appears to have several strengths & limitations. The design (retrospective observational) inevitably leads to confounding. That doesn’t mean the study is bad. It just mean it’s crucial to view the results as 1 piece in a puzzle

It just so turns out we do have results from other studies on this very same subject. One is a preprint from the UK. The other is a study published by the CDC. Both have their own strengths + limitations. And both have produced *different* results than the Israeli study.

Using a different study design, the Oxford preprint reports:
-No significant difference in infections btwn Group 1 (natural immunity) & Group 2 (2 doses of AstraZeneca)
-Greater protection for Group 3 (2 doses of Pfizer) over Group 1 (natural immunity)
So, different results. .

The CDC study found:
-“Natural immunity” group were 2.34 times *more* likely to experience re-infection than vaccinated people were to experience a breakthrough infection (vaccinated group=Pfizer, Moderna, & J&J)
So, again, different results. cdc.gov/mmwr/volumes/7…

Serological studies have also shown less consistent responses to new variants from “vaccine-induced immunity. Other research has also shown greater adaptability in mrna-vaccinated people’s immune response to new variants. It’s possible that other studies have shown the opposite!

Complicating things even further is unknowns about viral spread! We need more info on differential antibody presence & reaction in nasal mucosa. We need more data on duration of immune response & the nature of viral particles expelled by vaccinated vs. “naturally immune” people.

So, what to take away from all of this?

It’s all very scientifically interesting, but it doesn’t have much import for Public Health decisions in the U.S. If we had a vaccine shortage, the convo might be different. But we have a different issue: vaccine resistance.

“Natural immunity” exemptions don’t make sense from a feasibility standpoint & introduce gaps in coverage. They also breed the kind of flawed inferences that encourage “COVID parties” & vaccine resistance. The whole convo will definitely not help w/ childhood vaccination.

If you want to have a conversation about the fascinating science behind immunity, go for it. But don't be incautious. And don't let your *scientific* conversation fuel bad inferences or lead to sloppy conclusions about Public Health guidance.

Finally, a pet peeve: The majority of Americans--including highly educated ones--do not have experience navigating scientific research. It is encoded for many, though, that HUGE SAMPLE SIZE=DEFINITIVE RESULTS. This can lead to misinterpretations.

Just citing the overall sample size obscures the fact that this type of study has multiple confounds, despite the researchers' best efforts. It also obscures the fact that the *infected* samples were much smaller. Doesn't mean the study is bad. But we need to be more cautious

I wrote more about how anti-vaxxers are specifically abusing the "natural immunity" research here alternet.org/2021/09/anti-v…