@Ayyy7393 I got what was available, CoronaVac from sinovac, many people in my country got that one, the rest got either Pfizer or AstraZeneca. I know the Pfizer one has a little bit more side effects compared to Moderna or J&J but still we're talking about a day or two with muscle soreness and fatigue, nothing much to consider imo. As for efficacies, and this is just my opinion, if you're a relatively young (under 45) person with reasonably good health, I don't think you should be trying to get the best vaccine, I'm 29 and I got the ''worst'' one cause I just felt it would be wasted on me. All the vaccines are near 100 o 100% effective in preventing hospitalizations, so it's safe to say after being vaccinated with any of them, if you get Covid the worst case scenario is you get infected and it presents as a bad flu, a few days in bed taking tylenol. However once you factor in the age related risk, for someone like me, even if we do get infected, in all likelyhood I won't even notice. But someone in their 60s, 70s, they may get a bad case, and it still would be a lot worse for them, so again, just my opinion, if you're young and healthy, take whatever you get, it doesn't really matter for you.
I totally didn't forget the question and just kept writing... but back to it
Now for your parents, I'd say Moderna, then Pfizer, then J&J, unless one of them has mobility issues or they are at a very high risk of getting infected, then the J&J. You can always get a second vaccine if you want to but personally for older people getting protection now instead of in 2 months is worst considering. Imagine you go through all that trouble to get them moderna or pfizer and they get infected in the month between jabs, that would, using the technical term, fucking suck ass. Just know all 3 are going to protect them from severe Covid, and all 3 will more than likely protect them agains all Covid. The one thing you might want to consider is the adenovirus in the J&J vaccine. Blood clots cases aside, cause there are not enough to justiny not taking the vaccine, some immunosupresed people could in theory have a reaction to the virus, so if one of your parents have cancer or any condition suppressing the immune system, then I would prefer the Moderna. The Pfizer is almos the same as the moderna, it just hits people a little bit harder, so between those 2 I'd pick the Moderna.
But again, the main message here is whatever they get it's great. The risks are still very, very small, the difference in efficacy is mostly that with J&J they would have a marginally higher chance of presenting mild symptoms if infected, that's it. If that's all there's available it's ok, they should get it. But if you have all 3 available and you can choose, probably Moderna, then Pfizer, then J&J. If you'd have to wait to get the moderna or pfizer, then the J&J, that's most important thing, the sooner the better, no matter the vaccine.