[BostonCard]

Saw a reference on the Chronicle's virus tracker that a UK scientist believes there is an 80% probability that a vaccine will be ready by September; trials starting in a fortnight. 

https://news.sky.com/story/coronavirus-v...t-11971804

Not sure how you establish efficacy in that period. You can certainly establish broad safety (though you will still not be able to exclude rare events), and you can establish immunogenicity (that the vaccine can lead to antibody production).  However, to establish efficacy you would need to give it (or a placebo) to thousands of patients and watch them for a period of usually at least a year (though you might be able to accelerate it in this case) and compare how many in each arm develop Covid-19.  Simply establishing immunogenicity is not good enough, since there is not always a translation between producing antibodies against a virus and lower risk of infection.  Plus, in rare cases, you can get something called antibody dependent enhancement (ADE), in which the presence of antibodies actually helps the virus become more infectious.

BC

[BostonCard]

Saw a reference on the Chronicle's virus tracker that a UK scientist believes there is an 80% probability that a vaccine will be ready by September; trials starting in a fortnight. 

https://news.sky.com/story/coronavirus-v...t-11971804

Not sure how you establish efficacy in that period. You can certainly establish broad safety (though you will still not be able to exclude rare events), and you can establish immunogenicity (that the vaccine can lead to antibody production).  However, to establish efficacy you would need to give it (or a placebo) to thousands of patients and watch them for a period of usually at least a year (though you might be able to accelerate it in this case) and compare how many in each arm develop Covid-19.  Simply establishing immunogenicity is not good enough, since there is not always a translation between producing antibodies against a virus and lower risk of infection.  Plus, in rare cases, you can get something called antibody dependent enhancement (ADE), in which the presence of antibodies actually helps the virus become more infectious.

BC