In all phase3 trials large groups of people, as similar to each other in all variables as possible, will be either given a placebo or the actual vaccine and then go back to their normal lives.
The trials have a set "Covid-19 cases" mark where the stop to evaluate. The Pfizer vaccine has 164 contractions of Covid-19 as their mark to conclude the research. This research seems to aim for 151.
The Moderna vaccine, which is based on similar mRNA technology as BioNTech’s, is expected to be assessed by the FDA on a final analysis of 151 Covid cases among trial participants who will be followed on average for more than two months.
If both groups are similar enough you can then say how effective the vaccine is in preventing it.
This, by the way, is why most phase 3 trials take place in the US and/or Brazil (among other places): the more Covid-19 is around the faster you can get to the set number of contractions and conclude the phase 3.
The trials have a set "Covid-19 cases" mark where the stop to evaluate. The Pfizer vaccine has 164 contractions of Covid-19 as their mark to conclude the research. This research seems to aim for 151.
The Moderna vaccine, which is based on similar mRNA technology as BioNTech’s, is expected to be assessed by the FDA on a final analysis of 151 Covid cases among trial participants who will be followed on average for more than two months.
If both groups are similar enough you can then say how effective the vaccine is in preventing it.
This, by the way, is why most phase 3 trials take place in the US and/or Brazil (among other places): the more Covid-19 is around the faster you can get to the set number of contractions and conclude the phase 3.