How Effective Does COVID-19 Vaccine Need To Be To Stop Pandemic?

New computational model finds that a COVID-19 vaccine will have to be at least 80 percent effective to achieve a complete “return to normal”

Researchers around the world are racing to find a COVID-19 vaccine to eliminate the need for social distancing, mask wearing, and limits on interpersonal gatherings.

In a new study, a computer simulation model found that if 75 percent of the population gets vaccinated, the vaccine has to have an efficacy (ability to protect against infection) of at least 70 percent to prevent an epidemic and at least 80 percent to extinguish an ongoing epidemic. If only 60 percent of the population gets vaccinated, the thresholds are even higher, around 80 percent to prevent an epidemic and 100 percent to extinguish an ongoing epidemic.

The study was published in the American Journal of Preventive Medicine, published by Elsevier.

“Some are pushing for a vaccine to come out as quickly as possible so that life can ‘return to normal.’ However, we have to set appropriate expectations. Just because a vaccine comes out doesn’t mean you can go back to life as it was before the pandemic,” notes lead investigator Bruce Y. Lee, MD, MBA, Public Health Informatics, Computational and Operations Research, CUNY Graduate School of Public Health and Health Policy, New York, NY, USA.

“It is important to remember that a vaccine is like many other products – what matters is not just that a product is available, but also how effective it is.”

The investigators say the results of their study can provide targets for vaccine developers as well as shape expectations for policy makers, business leaders, and the general public.