top of page
  • info3591076

How long are COVID-19 vaccines effective?

One of the most pressing questions about COVID-19 vaccines is how long they can provide protection.

It may be decades, or a matter of months – the data necessary to figure that out is accumulating every day. Pfizer’s CEO said this week that after a full regimen of doses immunity will probably start to fade within a year. According to the WHO, it’s simply too early to know the exact duration of COVID-19 vaccines because both the disease and the science deployed against it aren’t yet fully understood.

Some early evidence is promising. The viruses that caused MERS and SARS are closely related to the virus behind COVID-19, and acquired immunity to both of those diseases has proved relatively durable.

In terms of COVID-19-specific research, Pfizer and BioNTech said earlier this month that their vaccine remains effective for at least half a year after the second dose, and a study of Moderna’s version reflected a similar duration. Immunization efforts will have to play out further before we can know more for certain.

The window of immunity enabled by vaccines could have an impact on efforts to fully re-open the global economy, and re-establish a sense of normalcy. For now, though, much of the focus has been on getting that first dose into arms, something many countries are still waiting for.

Though criticism has mounted of the pace of vaccinations in Europe, the region is still clearly better off than much of the world. In the image below, countries turn a progressively darker green as the share of their population fully vaccinated against COVID-19 increases through 13 April. The darkened countries are where no related data were available yet.



Recent Posts

See All


bottom of page