[Steve Carlton]

Third dose info.

https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(21)02249-2/fulltext

Discussion
In this large observational study conducted using nationwide mass vaccination data in Israel, we estimated that a third dose of the BNT162b2 mRNA COVID-19 vaccine is effective in preventing severe COVID-19-related outcomes. Compared with two doses of the vaccine administered at least 5 months before, adding a third dose was estimated to be 93% effective in preventing COVID-19-related admission to hospital, 92% in preventing severe disease, and 81% in preventing COVID-19-related death, as of 7 or more days after the third dose.
Third-dose vaccine effectiveness against admission to hospital and severe disease was estimated to be similar between males and females, and between individuals aged 40–69 years and at least 70 years. In those aged 16–39 years, the rate of these severe outcomes was too small for meaningful estimation of the booster effectiveness. Effectiveness was also similar among groups defined by the number of comorbidities.
Most previous studies on this topic have focused on the antibody response elicited by the third dose of mRNA vaccines.5
, 6
, 7
Two recent studies from Israel reported on the effectiveness of the third dose in preventing clinical outcomes. The first study estimated a reduction of 92–97% in the risk for severe disease starting from day 12 after receipt of the third dose,19
but did not adjust for pre-existing clinical conditions related to the risk of severe disease, and did not evaluate the effectiveness within subgroups. A second study, which adjusted for various confounders and used a test-negative design, estimated a reduction of 70–84% in the probability of testing positive for SARS-CoV-2 among the vaccinated,20
but did not consider more severe outcomes.


https://www.forbes.com/sites/williamhaseltine/2021/11/04/new-data-suggests-mrna-vaccines-work-best-as-a-three-dose-regimen/

Based on the same study linked above:

https://www.forbes.com/sites/williamhaseltine/2021/11/04/new-data-suggests-mrna-vaccines-work-best-as-a-three-dose-regimen/




A third does was anticipated and is not uncommon. Polio vaccination is a 4 dose regimen. Odds are said to be good the third dose could be durable.