People age 65 and over suffer the most severe cases of COVID-19 and have the highest associated mortality rate.
If the goal is to have COVID-19 vaccines ready for public use by early 2021, the only ones that have a chance are those that are currently in clinical trials. It is likely that most of these did not undergo preclinical optimization for an elderly population, meaning these first-generation COVID-19 vaccines may perform poorly in the people that need them most.
For the COVID-19 pandemic, it is too late to go back and build these considerations into preclinical testing. However, it is imperative that researchers still in the preclinical phase incorporate head-to-head testing of their vaccine candidates in young versus aged animals and develop strategies to optimize them in the latter. This will help the world prepare for the next outbreak of a dangerous coronavirus.
For that matter, a focus on the elderly should be incorporated into other vaccine development programs, including those to treat cancers, which have the highest incidence in older people.
