Can you have monkeypox more than once?

Scientists’ current knowledge of orthopox infections suggests that reinfection with monkeypox after infection or vaccination is unlikely – but some experts believe rare cases of reinfection may emerge as more data becomes available.

Why monkeypox reinfection is unlikely

In studies of smallpox patients, researchers reported that immune cells, which help the body fight the virus while killing infected cells, remain in the blood of survivors for up to 83 years after infection. Additionally, research suggests that neutralizing antibodies can be found in the body decades after an initial infection.

According to Paula Cannon, professor of microbiology and immunology at the Keck School of Medicine In the University of Southern Californiamost viral diseases follow a similar pattern.

The Jynneos vaccine, which is currently approved for monkeypox, is based on a weakened form of a similar virus called vaccinia virus, Cannon noted. “So you basically get an asymptomatic or incomplete infection that gives you a fairly high and complex level of immunity.”

Notably, data from vaccinia virus inoculations against smallpox suggest that the vaccine can provide reliable protection for at least five years, with some immunity for at least 10 years.

After several decades, researchers found comparable levels in vaccinated people and people who gained immunity through infection.

Will monkeypox reinfections appear in the future?

For now, CDC According to Brett Petersen, deputy chief of health services for the CDC’s Smallpox and Rabies Division, only a single report of possible monkeypox reinfection is known National Center for Emerging and Zoonotic Infectious Diseases. However, Petersen noted that the CDC expects reinfections to be rare.

However, real-world data on monkeypox is still very limited. According to David Cennimo, an infectious disease expert at School of Medicine Rutgers New Jerseyit is possible that there will be reports of reinfections in the future.

“What we don’t know is whether this new outbreak and epidemiology and mode of transmission will impact some of the effects previously seen in monkeypox and other related viruses like smallpox. So I think there’s still more to learn there,” noted Petersen.

“We don’t have a lot of data on this, but we can extrapolate what we know about other orthopox infections, namely smallpox,” said Jason Farley of the Johns Hopkins Nursing School.

“People infected with smallpox were protected from reinfection. There’s probably a similar phenomenon that occurs in monkeypox where people don’t get reinfected — and definitely not right away,” Farley said.

According to Cennimo, it’s possible for immune memory to weaken several years after monkeypox infection or vaccination.

“There may be some time over a number of years that someone could become infected again or that their immunity may drop or if they [become] immunocompromised,” Farley added. “In general, we expect that most people will not be susceptible to re-infection in the near future, which I think will be useful when reflecting on the trajectory of this outbreak in non-endemic countries.”

For years, the CDC has recommended that workers who come into close contact with smallpox or monkeypox be vaccinated every two or ten years, respectively.

However, Cennimo noted that future recommendations will likely depend on the trajectory of the current outbreak. “I couldn’t predict if we’re going to tell patients who are getting the monkeypox vaccine now that they’re going to need a monkeypox booster shot in three years,” he said. “If we don’t control this transmission now and this becomes an endemic infection, it certainly may.” (Sheikh, New York Times, 9/8; fjord MedPage today, 30.6.; Fernandez, Johns Hopkins Panel, 8/12)