In April, the U.S. Centers for Disease Control and Prevention reported almost 58% of American had been infected with the coronavirus. And the risk of getting it again may be higher as a result of the current surge, driven by contagious omicron subvariants BA.4 and BA.5.
Reinfection is when a person has the virus, recovers and then gets it again, according to the CDC.
Reinfection is uncommon, but women, immunocompromised people and those who were previously hospitalized are more susceptible, according to a December 2021 Kaiser Permanente study.
Do previous infections protect you against reinfection?
In short, yes — but the degree of protection depends on the individual and their immune response.
According to the CDC, antibodies to COVID — proteins generated by the immune system — can be detected in the blood of people who have recovered from COVID or people who have been vaccinated against it. Developing them is just “one part” of the body’s immune response.
“You do develop antibodies after COVID, but the amount and the degree of the response varies greatly, and it depends on numerous factors,” said Dr. Natascha Tuznik, a UC Davis infectious disease specialist.
Fully vaccinated individuals who are healthy and do not have any underlying medical conditions will likely experience mild symptoms from getting infected with COVID again. This patient is known as a “normal host.”
It is estimated that this group of patients have a “low risk of repeated infection with a similar variant for at least six months,” according to the Mayo Clinic.
But this is not the case for immunocompromised individuals — even if they are fully vaccinated and boosted.
“They still might not be able to mount an adequate antibody response,” Tuznik said. “Therefore, when they get infected, their symptoms may be much more severe and their antibody response is blunted, compared to somebody with a normal immune response.”
Does reinfection lead to long COVID?
Research on this is inconclusive.
The CDC defines long COVID as “new, recurring, or ongoing health problems” that could appear at least four weeks after catching the coronavirus.
Based on observational data, long COVID is more common in people who had a severe outbreak or those who are unvaccinated — which is also the same group that gets reinfected more often, Tuznik said.
In a June study published by the VA Saint Louis Health Care System and Washington University School of Medicine, researchers compared the symptoms of a half million infected COVID patients to more than 5 billion noninfected control patients.
The findings from this study show reinfection heightens the risk for conditions associated when experiencing long COVID.
Post-COVID conditions exist on a spectrum and can include fatigue, fevers and symptoms that worsen after mental or physical exertion, among other neurological and respiratory symptoms, according to the CDC.
“Their study suggests that [reinfections] do contribute potentially to long COVID,” Tuznik said.
Does reinfection make you susceptible to other disease?
“We know new health conditions may develop and have been reported after COVID-19, particularly in patients who have had severe COVID-19 disease,” Tuznik said.
Some of the underlying conditions, which can be developed from COVID, include autoimmune disease, diabetes, kidney failure and neurological complications — which can make individuals more likely to catch other illnesses, the infectious disease specialist said.
“Some patients have had these underlying conditions and they may worsen, but it’s also been reported that patients develop these symptoms ‘de nouveau’ meaning new,” she said.
If you develop one of these conditions after a severe breakthrough, Tuznik said you may be indirectly more susceptible to other infections as well, such as influenza or the common cold — and even more complicated ones.