Thread by @DrEricDing

⚠️BREAKING—REINFECTION & NATURAL IMMUNITY—new CDC study in hospitalized adults finds: unvaccinated people with prior #COVID19 infection recently were **5 times more likely** to be reinfected / get breakthrough versus people recently fully vaccinated! 🧵 cdc.gov/mmwr/volumes/7…

2) Here’s the background—
Previous infection with SARS-CoV-2 or COVID-19 vaccination can provide immunity and protection against subsequent SARS-CoV-2 infection and illness. ➡️ but the big debate has been which immunity is stronger? Offers more protection? That’s the study aim.

3) “Among COVID-19–like illness hospitalizations among adults aged ≥18 years whose previous infection or vaccination occurred 90–179 days earlier, odds of laboratory-confirmed #COVID19 among unvaccinated adults with previous SARS-CoV-2 infection were 5.49-fold higher”…

4) …”than among fully vaccinated recipients of an mRNA COVID-19 vaccine who had no previous documented infection (95% confidence interval = 2.75–10.99).” Wow 👀

📌 Notably this was a clean comparison of fully vaccinated with no prior infection vs those with prior infection!

5) What are the implications for public health practice?

📍All eligible persons should be vaccinated against COVID-19 as soon as possible, including unvaccinated persons previously infected with SARS-CoV-2. ⚠️

6) Let’s dive into #DeltVariant and reinfection from natural immunity vs breakthroughs by vaccination— reinfection via natural infection is 7.55x higher than breakthroughs!!!

7) What about vaccine type? Reinfection risk is 5x higher with natural immunity vs Pfizer vaccine. But reinfection risk is 7.3x higher with natural immunity vs Moderna! Moderna is again stronger protection and natural immunity much much weaker. 👀

8) Among elderly, natural immunity is almost 20x weaker against reinfection than vaccines!! ⚠️ But even among 18-64, natural immunity is still 2.57x weaker protection than vaccines!! ⚠️

9) Someone warned about this exact issue over a month ago…. Some naysayers had dismissed it because it was not peer reviewed or from CDC. But it was clear vaccine immunity had less breakthroughs than natural immunity had reinfections.

https://twitter.com/drericding/status/1443411199920594956

10) to be clear—even if natural immunity had equal reinfection risk as vaccine had breakthroughs—vaccines would still be better. Because it is much much safer. And don’t forget the selection bias in natural infection—that “dead men tell no tales” where you only measure survivors.

https://twitter.com/vincentrk/status/1454198976060792840

11) Thus, natural immunity should be called “NATURAL INFECTION SURVIVORS” who survived an earlier infection. That’s why when even if “natural immunity” people higher antibodies—you’re selecting people who didn’t succumb last time. ➡️And also don’t forget #LongCovid debilitation.

https://twitter.com/drericding/status/1443564127713124352

12) But folks who tout natural infection focus on those who *survived*, and they know they had COVID often by looking at just those with enough antibody response in antibody tests! Many survivors **who don’t mount antibodies are often excluded** from studies! Hence it’s biased!

13) Wow- 1 in 4 infected with COVID do NOT develop antibodies! There goes natural immunity strategy — it’s not reliable! Hence get #vaccinated!

https://twitter.com/alinouriphd/status/1454564520941268993

14) We should not be talk about natural or artificial immunity at all. Vaccines stimulate your own natural immunity to fight #SARSCoV2 and other viruses. That’s how they work. What “natural immunity” folks really want to say is “let’s mass infect everyone” for expediency. 👀

https://twitter.com/michaelmina_lab/status/1455200208841846785