Study referenced in #18
Study link:
https://www.nature.com/articles/s41586-021-04060-7
In addition to the summary below, the researchers found that in those not previously infected, "mRNA vaccines produces high levels of plasma neutralizing activity" but these wane requiring boosters.
More and more it seems that the Israelis got it right ...the best protected are convalescents who get a mRNA vaccine following infection. So far it seems that one dose is sufficient, but that may change as more is learned about SARS-CoV-2 overall and especially as Omnicron variant research studies are published.
Summary from the Rockefeller University website:
Nussenzweig and colleagues resolved to tease out any differences in memory B cell evolution by comparing blood samples from convalescent COVID-19 patients to those from mRNA-vaccinated individuals who had never suffered natural infection.
Vaccination and natural infection elicited similar numbers of memory B cells. Memory B cells rapidly evolved between the first and second dose of the Pfizer and Moderna vaccines, producing increasingly potent memory antibodies. But after two months, progress stalled. The memory B cells were present in large numbers and expressed potent antibodies, but the antibodies were not getting any stronger. Also, although some of these antibodies were able to neutralize Delta and other variants, there was no overall improvement in breadth.
With convalescent patients, on the other hand, memory B cells continued to evolve and improve up to one year after infection. More potent and more broadly neutralizing memory antibodies were coming out with every memory B cell update.
There are several potential reasons that memory B cells produced by natural infection might be expected to outperform those produced by mRNA vaccines, the researchers say.
It is possible that the body responds differently to viruses that enter through the respiratory tract than those that are injected into our upper arms. Or perhaps an intact virus goads the immune system in a way that the lone spike protein represented by the vaccines simply cannot. Then again, maybe it’s that the virus persists in the naturally infected for weeks, giving the body more time to mount a robust response. The vaccine, on the other hand, is flushed out of the body mere days after triggering the desired immune response.
