Graphic by Annie Lin.
It’s the question on everyone’s minds: when will a COVID vaccine be ready? Unfortunately, the answer is not as simple as a specific date. Even vaccines on track to secure emergency FDA approval by early 2021 will have to clear additional regulatory hurdles before they can be widely distributed.
In public health crises like the COVID-19 pandemic, the FDA can waive some elements of its review processes in order to get lifesaving products to market more quickly. So what standards will COVID vaccines have to meet to demonstrate their safety and efficacy? Per emergency use authorization (EUA) protocols, vaccines in phase III clinical trials must reduce the risk of contracting COVID by at least 50 percent. This is evaluated once the total number of symptomatic COVID cases among the tens of thousands of clinical trial participants reaches 150. However, pharmaceutical companies can also conduct interim data collection before case numbers reach this threshold and elect to vaccinate everyone in the control group as well if a vaccine shows high efficacy early on. But this change turns double-blinded trials into unblinded trials, making it difficult to monitor the vaccine’s effects in an unbiased way over longer periods of time.
Vaccine manufacturers must also keep in mind the vaccine distribution, which is typically only viable if stored below a certain temperature. Although speed is undoubtedly a driving factor in COVID-19 vaccine development, companies must also navigate safety and logistical concerns as phase III trials continue.