[M T]

I don't think this was mentioned here before...

As you know, the interval between the Pfizer doses is 21 days, while the interval between the Moderna doses is 28 days.  

The question is, what if you don't get your 2nd dose on the appointed day?

OWS's Dr. Slaoui indicated that normally, the longer time between two doses, the better the effectiveness.  However, the longer the time between them, the more likely that you might get the illness in that time.

So, if you are quarantining (for exposure, vs isolating for having COVID) when your 21 days is due for a 2nd Pfizer shot, my understanding is you probably are fine to wait until you can safely get your 2nd shot.     (Always, talk to your physician for health advice)

I have not heard any official position on what to do about the 2nd dose if you get COVID after the 1st shot but before the 2nd shot.  I expect that was covered in the FDA approval, and I'm sure your health agency will know what to do and will advise you.

I don't think we know what the immunity profile is if the booster is given at different times, or if it is not given at all. There is evidence of immunity after 10 days from the Pfizer vaccine, but no profile after 21 days because everybody in the trial got a booster. No trial has been done with other delays AFAIK, and no trial has been done with no booster AFAIK. Will such trials happen? I doubt it in the short term and in the long term it may be impossible because there won't be enough disease.
The 300 lb gorilla is how long does immunity last with the 21 day booster? Naturally, we can't know yet. Hopefully at least a year, but we don't know.

Agree about the gorilla. However, neither Moderna nor Pfizer graphs seemed to have any more incidence in the vaccine group at the end of their trials than at the mid-point.

I just took a look at the Moderna numbers.  About 8% (1100) of each of the placebo & real medicine groups did not get their 2nd dose.   Maybe that was for cause, but maybe there is some hint of data there.  (Actually, there are very weak numbers.  Based on 2 cases in the vaccine group and 4 in the placebo group, the estimate of efficacy of 1 dose is 43%, but the 95%CI is -300% to 95%)

The Moderna numbers separate from the placebo at about 12-14 days after first dose.

I haven't looked at all the Moderna numbers, but the one that I'd like to understand better is one number among those that withdrew from the study.  17 withdrew from the vaccine group due to "physician decision" while only 2 withdrew for that reason from the placebo group.

[M T]

I don't think this was mentioned here before...

As you know, the interval between the Pfizer doses is 21 days, while the interval between the Moderna doses is 28 days.  

The question is, what if you don't get your 2nd dose on the appointed day?

OWS's Dr. Slaoui indicated that normally, the longer time between two doses, the better the effectiveness.  However, the longer the time between them, the more likely that you might get the illness in that time.

So, if you are quarantining (for exposure, vs isolating for having COVID) when your 21 days is due for a 2nd Pfizer shot, my understanding is you probably are fine to wait until you can safely get your 2nd shot.     (Always, talk to your physician for health advice)

I have not heard any official position on what to do about the 2nd dose if you get COVID after the 1st shot but before the 2nd shot.  I expect that was covered in the FDA approval, and I'm sure your health agency will know what to do and will advise you.

I don't think we know what the immunity profile is if the booster is given at different times, or if it is not given at all. There is evidence of immunity after 10 days from the Pfizer vaccine, but no profile after 21 days because everybody in the trial got a booster. No trial has been done with other delays AFAIK, and no trial has been done with no booster AFAIK. Will such trials happen? I doubt it in the short term and in the long term it may be impossible because there won't be enough disease.
The 300 lb gorilla is how long does immunity last with the 21 day booster? Naturally, we can't know yet. Hopefully at least a year, but we don't know.

Agree about the gorilla. However, neither Moderna nor Pfizer graphs seemed to have any more incidence in the vaccine group at the end of their trials than at the mid-point.

I just took a look at the Moderna numbers.  About 8% (1100) of each of the placebo & real medicine groups did not get their 2nd dose.   Maybe that was for cause, but maybe there is some hint of data there.  (Actually, there are very weak numbers.  Based on 2 cases in the vaccine group and 4 in the placebo group, the estimate of efficacy of 1 dose is 43%, but the 95%CI is -300% to 95%)

The Moderna numbers separate from the placebo at about 12-14 days after first dose.

I haven't looked at all the Moderna numbers, but the one that I'd like to understand better is one number among those that withdrew from the study.  17 withdrew from the vaccine group due to "physician decision" while only 2 withdrew for that reason from the placebo group.