That study which showed the Oxford AZ vaccine reducing transmission is seriously good news. Granted it’s only in preprint, so not yet peer reviewed etc, but the effect was so strong (67%) it’s unlikely to disappear altogether on closer examination.
I am wondering how likely it is that the same will apply to other vaccines and to natural immunity after infection, perhaps in proportion to the degree of protection from symptomatic infection. After all, it’s not as if the immune system is doing anything fundamentally different.
Does anyone know much about this?
Actually, the stuff about transmission was a subsidiary finding in the report. The main things they were keen to tell you about was 76% protection from symptomatic Covid 22 days after a single dose which persists until 12 weeks, and that the protection achieved with a 12 week gap was stronger than when the gap was less than 6 weeks. I similarly wonder whether that will also apply to all vaccines... or maybe mRNA vaccines (Pfizer, Moderna) are so different that it won’t.
www.ox.ac.uk/news/2021-02-02-oxford-coronavirus-vaccine-shows-sustained-protection-76-during-3-month-interval