PENNSYLVANIA (WHTM) — So your COVID-19 test came back with that dreaded second line — a positive result. But can you get COVID back to back?

“Omicron has demonstrated the ability to infect people that had prior variants, so yes it is possible to be reinfected,” said Dr. Joseph Kontra, chief of infectious diseases at Penn Medicine Lancaster General Health.

On the upside, said Dr. John Goldman, infectious disease specialist at UPMC, most experts assume that individuals are immune from COVID and will likely not get it again within about 90 days after a COVID infection. Two factors that may impact reinfection are variants and timing.

How do COVID variants impact reinfection?

New COVID variants probably make breakthrough infections (infections in people who are vaccinated) and reinfection more likely, said Goldman. And Kontra noted that omicron subvariants may even be shortening that 90-day window of unlikely reinfection, although they haven’t been around quite long enough for experts to know that for sure yet.

As far as catching the same COVID variant twice, Goldman says the rapid development of new variants has prevented experts from observing the potential for multiple infections by the same strain of COVID.

The original strain circulating in March 2020 was replaced by the alpha variant in the spring of 2021, which was replaced by delta around the summer, and then omicron began dominating around the start of 2022, and now there are several omicron subvariants circulating, Goldman explained.

With most other coronaviruses, like the ones that cause the common cold, individuals can get the same virus twice, Goldman noted, so it may be the same for COVID-19.

When does COVID immunity decline?

In addition to new variants, timing plays a role in the possibility of reinfection. The longer it’s been since one has recovered from a COVID infection or since one has received the COVID vaccine, the more likely reinfection or breakthrough infections become as one’s immunity declines, Goldman explained.

“You probably can’t get reinfected in the first 90 days, but after 90 days, the further and further out you are from your original infection, the more likely it is that you can be reinfected,” Goldman hypothesized.

However, breakthrough infections or reinfections are generally less severe because the body does still have some defense against the virus, Goldman and Kontra noted.

“Partial immunity is best at preventing severe disease, it is not as good at preventing breakthrough infections. But when you’ve previously had COVID or you’ve previously had a vaccination, even if you’re infected with a new variant, you’re still less likely to get severe disease,” Goldman said.

While vaccines and natural infection both provide some defense against the virus, Kontra says there may be some difference between the two types of immunity.

“It turns out that being vaccinated and boosted may be better than having an omicron subvariant infection in terms of protection going forward. So for some reason, the omicron subvariants can infect each other, so to speak, but vaccination tends to provide a bit more protection,” Kontra said.

What should you do if you test positive for COVID?

Before reaching that period of post-infection heightened immunity, individuals who test positive for COVID-19 and have a mild infection should isolate for at least five days from the first day they had symptoms, the CDC says. Isolation can end after five full days if individuals’ symptoms are going away and they have not had a fever for 24 hours without taking fever-reducing medication, the CDC says, and individuals who had a COVID infection should wear a mask in public for an additional five days following the end of their isolation.

The CDC also notes that people who have moderate symptoms like difficulty breathing should isolate for 10 days, and people who have severe illness and require hospitalization or ventilation support should isolate for 10-20 days.

Although experts believe there is a 90-day window after infection in which people are unlikely to catch COVID again, Kontra noted that if you do start to develop COVID symptoms within that time period, you should take another test and follow all the typical COVID precautions to be safe.