There are already a good number of vaccine on the market. How they are going to figure out which one will have a better result? Specially when the virus is evolving, and people need to take 2 vaccine shots, with a 2-4 week pause between them. And not to forget that pharmacists always adding and improving something in vaccine. With all that variables, how to get a clear result from vaccination?
Phase III trials have been completed for all of the approved vaccines, and their efficacy is known to everyone now. The rates for various vaccines measured from the Phase III trials are as follows:
Pfizer/BioNTech - 95%
Moderna - 95%
Gamaleya - 91%
Novavax - 89%
Sinopharm - 79%
AstraZeneca/Oxford - 70%
Johnson & Johnson - 66%
Sinovac Biotech - 50%
Many of the countries are using more than 1 vaccine, depending on the availability. But as you can see from the list above, after the vaccination, there will be anywhere from 50% to 95% reduction in the new cases.