Yale Study Shows Natural Immunity Lasts 3x Longer than Vaccine-Induced Immunity

https://yaledailynews.com/blog/2021/10/07/covid-19-reinfection-is-likely-among-unvaccinated-individuals-yale-study-finds/

A recent study at the Yale School of Public Health analyzed immunological data from close viral relatives of SARS-CoV-2 to determine how long natural immunity from infection lasts for unvaccinated individuals.

Jeffrey Townsend, the study’s lead author and Yale professor of biostatistics, explained that it can take several years to collect enough data to determine the rate of reinfection of an infectious disease. This creates a problem for researchers, as COVID-19 has only been actively circulating for about a year and a half. In the absence of sufficient empirical data, a team of Yale researchers and colleagues at other institutions sought to determine the rate of reinfection by analyzing immunological data from SARS-CoV-1, Middle East respiratory syndrome and human coronaviruses. With an understanding of how these viruses evolve and how they are related to each other, the team was able to model the likelihood of reinfection for SARS-CoV-2, the virus that causes COVID-19.

“The overall goal of the study was to provide an answer to a question that at this point in the pandemic would be impossible to answer empirically, which is how long after you’ve been infected by SARS-CoV-2 can you expect to possess immunity against the virus before you become vulnerable to reinfection?” said Hayley Hassler, a research associate at the School of Public Health and one of the study’s co-authors.

The study showed that the duration of immunity is relatively short. According to Hassler, the risk of reinfection is about five percent at three months after the initial infection. After 17 months, that number increases to 50 percent.  

After 5 months, the efficacy of the J&J vaccine is only 3%.

After 6 months, Pfizer's efficacy drops to 20%.

There hasn't been as much data released on Moderna, but early indications show it holds up better, at about 64% at 5 months. This would tend to make sense, considering the Moderna vaccine has about twice the mRNA that the Pfizer shot does. I expect it's efficacy to drastically wane (similar to Pfizer) at about 10-12 months. 

The important thing to note is that natural immunity doesn't hit 50% until 17 months. The only vaccine that would be able to make that claim would possibly be Moderna, and that would be after 3 jabs.