The announcement by Pfizer and BioNTech of results from the third phase of their vaccine
trial has been greeted with enthusiasm around the world. It is particularly welcome for the
populations of countries whose governments have failed so spectacularly in protecting them
from the burden of disease generated by COVID-19. It also demonstrates that the immune
responses elicited by many other vaccines in human trials may lead to protection, a view
supported by the early results from the Sputnik 5 vaccine in Russia. We can expect
preliminary results from other trials over the next few weeks.
In our brief response, we discuss some of the important challenges for successful roll out of this (and other) vaccines.
