It usually takes several years to develop a vaccine. The successful development of COVID-19 vaccines is down to foresight, hard work and good luck. Given the urgency of containing a global pandemic, unprecedented resources were directed at vaccine development.
Crucially, clinical trials were streamlined without compromising on safety. Tens of thousands of people volunteered to take part in trials; phases of trials overlapped rather than being conducted consecutively; and regulators began ‘rolling reviews’ while trials were ongoing.
At the same time, even before vaccines were independently approved by regulators, governments placed advance orders for vaccines and companies began manufacturing. This meant that when regulators were satisfied that vaccines were safe and effective, millions of doses could be shipped around the world.
