The problem with Pfizer is that the efficacy of the vaccine wanes after 5-6 months. A recent study found that the efficacy of Pfizer reduces to just 42%, after five months (compared to this, Moderna fares much better and it has a 76% efficacy after 5 months). Then you need to get a booster dose to remain protected against COVID. This is one of the disadvantages for mRNA vaccines, when compared to Non-Replicating Viral Vector types. On the other hand, the overall efficacy of vaccines like AstraZeneca (AZD1222) may be lower, but they offer protection for a much longer duration.
Then get the needed booster after 5 months, problem solved. Doesn't matter was vaccines you got, as long as you have the protection against covid and it's variants, it's better as compare to not getting any vaccine at all because you don't want to. So there's no advantage or disadvantage, I'm sure the government are more willing or if getting a booster will cost some money, then do it. Now kids are the next demographics to be vaccinated (age 12-17) and hopefully it will be roll out in the coming months, so that when they go face to face in school, they are protected. Or this could be mandated by any schools and universities before allowing any students to go again in schools.