Any potential coronavirus vaccine may not offer lifelong protection against the virus. On Monday, infectious disease expert Dr. Anthony Fauci revealed that coronavirus immunity might be “finite” and might require a booster for extended protection.  

With the race to develop a coronavirus vaccine still on, the question of how long the vaccine might offer protection against infection remains unknown. In a Q&A discussion with Dr. Francis Collins of the National Institutes of Health, Dr. Fauci revealed that the coronavirus vaccine might not confer lifelong immunity the way a measles, mumps, and rubella (MMR) vaccine does.

Asked how long antibodies might offer protection against the coronavirus, Dr. Fauci said, “We do not know.” “With this spike protein that’s being presented in the way that we do it with primes and in some cases boosts, we’re going to assume that there’s a degree of protection, but we have to assume that it’s going to be finite,” said Dr. Fauci. “It’s not going to be like a measles vaccine,” he added.

According to Dr. Fauci, the role of antibodies in the development of a coronavirus vaccine will take on even more significance as it would determine how well the vaccine works and how often people should get it. “So there’s going to be follow up in those cases to see if we need a boost,” he said. He said as long as the effectivity of the coronavirus vaccine remains unknown, people may need a boost to make sure they remain protected from the virus.

Dr. Fauci also said reports of recovered COVID-19 patients being reinfected with the virus might be inaccurate, as the test used to detect the disease could pick up fragments of the virus that remain in the bodies of recovered patients. The presence of such fragments, he said, does not necessarily mean that the person has been reinfected.

“There are no documented cases where people got better and actually got sick again in the sense of virus replicating,” he said. “I wouldn’t be surprised if there’s a rare case of an individual who went into remission and relapsed. But Francis, I can say with confidence, that it is very unlikely if it’s a common phenomenon,” he explained.

Last week, the World Health Organization (WHO) reported that 16 companies with vaccine candidates were already conducting their human trials globally.

Coronavirus COVID-19 Laboratory Test, Cure, Vaccine Andressa Parreiras, Biomedic, and Larissa Vuitika, biologist, work in a laboratory during the extraction of the virus genetic material on March 24, 2020 in Belo Horizonte, Brazil. The Ministry of Health convened The Technological Vaccine Center of the Federal University of Minas Gerais laboratory to conduct research on the coronavirus (COVID-19) in order to diagnose, test and develop a vaccine. According to the Ministry of Health, as of Tuesday, March 24, Brazil has 1.891 confirmed cases of the coronavirus (COVID-19) and at least 34 recorded deceases. Pedro Vilela/Getty Images