In all probability the very first thing to say is that the March date isn’t solid in stone.
By way of regulation, there are three most important points – efficacy (does it work?), security (each recognized and unknown dangers) and high quality. The final is definitely one of many tougher points and truly takes the longest to work by – are the manufacturing controls sufficient at every of the factories during which the vaccine is being produced? Is there the identical dose of vaccine in every vial and every batch? What controls are there to ensure nothing else will get in (ie contamination)? How lengthy can the vaccine be saved within the freezer, as soon as taken out of the freezer and as soon as made up?
There are additionally implementation points – the distribution chain (clearly a bit tougher coming from the factories within the northern hemisphere right into a southern summer time), coaching of workers who shall be giving the vaccine, understanding the place the distribution factors shall be, ensuring we’ve the security techniques in place to select up and assess any unintended effects.
Clearly there are lots of folks actively engaged on all these questions throughout all ranges of presidency and we’re constructing on current immunisation applications.
However simply as a comparability, we distribute roughly 18m doses of flu vaccine between April and August every year, with a recognized provide schedule and established infrastructure. For a Covid vaccine, we’ll must administer 40 or 50m doses of a vaccine as rapidly as doable, the place we might want to give two doses, with an unsure provide schedule, tough chilly chain necessities, vaccines of various varieties and utilizing new vaccines the place we are going to need to monitor any aspect impact that happens.