[BostonCard]

2) I have read many times that the first vaccines may not be the best vaccines, and that we may need boosters, but you might be "stuck" with the vaccine you take first. IE, if you take Pfizer now, but this fall we realize some other vaccine (that isn't even in Phase III now) is the "best", why might you be "stuck" continuing to take the vaccine you took first? In the past, what scenarios required this?

I don't think there's evidence of this.  For vaccines requiring two doses, you may need to take the second dose from the same vaccine maker (though maybe not if the antigens are similar enough).  After that, you can probably switch vaccines, though you might have to take two doses rather than getting a single booster, though that has not been worked out either.

BC

[BostonCard]

2) I have read many times that the first vaccines may not be the best vaccines, and that we may need boosters, but you might be "stuck" with the vaccine you take first. IE, if you take Pfizer now, but this fall we realize some other vaccine (that isn't even in Phase III now) is the "best", why might you be "stuck" continuing to take the vaccine you took first? In the past, what scenarios required this?

I don't think there's evidence of this.  For vaccines requiring two doses, you may need to take the second dose from the same vaccine maker (though maybe not if the antigens are similar enough).  After that, you can probably switch vaccines, though you might have to take two doses rather than getting a single booster, though that has not been worked out either.

BC