Although the numbers are small, this trial also gives an indication that vaccination is effective in older and BAME individuals and prevents severe disease, all of which are key to allowing the world to start opening up again. The absolute prerequisite for a Covid-19 vaccine is that it stops people becoming ill enough to require hospital treatment and stops people dying. The preliminary data reported here suggest that this vaccine – and by extension, the Pfizer/BioNtech vaccine – will achieve this goal.
The safety data also look promising. The side-effects of vaccination appear to be in line with those typically seen for other adult vaccinations, including the seasonal influenza vaccination which is administered in many millions of doses every year.
One important unknown is whether this vaccine, or any of the vaccines currently in trials, prevents disease transmission. It is likely that vaccines that prevent symptomatic disease will reduce the duration and level of infectiousness, and thus reduce transmission, but we don*t yet know if this effect will be large enough to make any meaningful difference to the spread of the virus within communities.
But, overall, this is excellent news. Having more than one source of an effective vaccine will increase the global supply and, with luck, help us all to get back to something like normal sometime in 2021.