Claim: Natural immunity against Covid does not wane
A new preprint Qatari study says that Natural immunity protects against severe infection
A new, extremely large Qatari preprint population study showed that prior infection with Covid for unvaccinated people protects against severe, critical or fatal infection at an effectiveness level of 97.3% (95% CI: 94.9- 98.6%),.
They studied a large number of unvaccinated people in Qatar, 7,995 of whom had already been infected with the one of the earlier variants and then caught Omicron; in the Omicron wave, only 5 of these progressed to severe Covid-19.
12,230 people in the group that had not been infected with the Delta variant caught Omicron later on, 26 progressed to severe, 7 to critical, and 5 to fatal Covid-19.
It was a huge population study, and they were very rigorous at excluding people who didn’t correspond to the facts were looking at:
These are their charts showing protection against reinfection. Note that the error bar in week thirteen of the bottom chart is huge because there were no reinfections in that month.
This appears to be a very rigorous study, and they are only trying to find out the answer to one question: to what degree does prior natural infection with Covid protect against new Covid infections?
Let’s see whether it gets published.
It was an article in Exposé that alerted me to this study, where it is compared to a study from Qatar published in the NEJM showing the protection afforded by the Pfizer vaccines, which wanes with time.
Note the second chart below; the effectiveness against severe, critical or fatal Covid infections afforded by 2 doses of the Pfizer vaccine wanes after six months, and overall is nowhere near the effectiveness of natural infection.
https://www.nejm.org/doi/full/10.1056/nejmoa2114114
References
https://www.medrxiv.org/content/10.1101/2022.07.06.22277306v1.full.pdf
https://www.nejm.org/doi/full/10.1056/nejmoa2114114
https://expose-news.com/2022/07/14/natural-immunity-covid-doesnt-wane-vaccinated-developing-aids