Moderna seems to have less side effects that Pfizer. AstraZeneca is similar to Johnson and Johnson vaccine. If I have a choice (I’m in the group last in line for vaccination), I’ll probably take the J&J vaccine; despite its “C” rating in my previous post, all these vaccines are moral. And the JJ vaccine is said to be one shot instead of two shots. This is a great advantage, as the govt is now saying that they do not have any vaccines in reserve for second shots, and some persons who received Moderna might receive Pfizer as their second shot, or vice versa. A single-shot vaccine is preferable. So far, also JJ seems to have the fewest side effects. AZ and JJ are more traditional vaccine types than Moderna and Pfizer.
All things considered, I would prefer JJ over the others now available. However, if Novavax becomes available, depending on what their Phase II and III studies may show, that might be even better. We don’t know at this point.