Will people have to get a COVID-19 vaccine every year?
In less than a year from the emergence of SARS-CoV-2, several safe and effective COVID-19 vaccines were created and authorized for use in the United States and globally.
Tens of millions of doses of these vaccines have already been administered. Will people have to receive a COVID-19 vaccine every year, as is recommended for seasonal influenza? We asked Amesh A. Adalja, MD, a senior scholar at the Johns Hopkins Center for Health Security.
What the frequency of SARS-CoV-2 vaccination may be in the future is an open question. The need for repeat vaccination is conditioned by two factors that do not always overlap — the duration of immunity and the need to update the contents of the vaccine. For example, tetanus boosters are given every 10 years and are not different in composition from the original vaccine. Influenza, on the other hand, because of its ability to mutate away from vaccines, often necessitates strain changes on an annual basis. The novel coronavirus, though sharing some similarity with influenza in terms of symptoms and transmission, is from a distinct family of viruses and has its own rates of mutation.
In my analysis, a recommendation for repeat vaccination would be necessary only after conducting natural history studies that assessed a vaccinee’s ability to be reinfected after a period of time and determined to be contagious or significantly ill. These studies will be conducted.
Additionally, in light of the emergence of variants, companies are updating existing vaccines and the FDA has developed an expedited path for approval of variant vaccines — if needed. The threshold for such a need, to me, would be vaccinees getting infected and developing symptoms severe enough to land them in the hospital. Fortunately, current vaccines — even in the face of concerning variants — seem durable at preventing what matters: severe disease, hospitalization and death.
Lastly, I personally would be interested to learn about the experience with veterinary coronavirus vaccines (given to cattle and chickens) and the duration of immunity they confer and whether they need regular updates.
Click here to read the Cover Story, "Past research and ‘unlimited resources’ spur fast development of COVID-19 vaccines."