CDC: Unvaccinated more than twice as likely to get COVID-19 reinfection

Unvaccinated people are more than twice as likely than the fully vaccinated to get reinfected with COVID-19, according to a Centers for Disease Control and Prevention (CDC) study released Friday.

The research determined that unvaccinated Kentucky residents who had a confirmed coronavirus infection last year had a “significantly higher likelihood of reinfection” than those considered fully vaccinated. The study concluded that the unvaccinated were 2.34 times more likely to contract COVID-19 again.

The CDC’s Morbidity and Mortality Weekly Report (MMWR) counters the argument that people previously infected with the coronavirus don’t need the vaccine because natural immunity offers enough protection. 

The agency has already recommended that people previously infected with COVID-19 get vaccinated for more protection. 

The study involved 246 Kentucky residents who were reinfected in May and June this year after having a confirmed 2020 case. They were compared to 492 controls who had a 2020 infection but were not reinfected.

Reinfection had previously been studied in laboratory settings, but the CDC noted there has been limited real-world data on the subject. 

“These findings suggest that among persons with previous SARS-CoV-2 infection, full vaccination provides additional protection against reinfection,” the report reads. “To reduce their risk of infection, all eligible persons should be offered vaccination, even if they have been previously infected with SARS-CoV-2.”

The CDC said that natural immunity after recovering from COVID-19 without a vaccination “is suspected to persist for ≥90 days in most persons,” acknowledging it is “not well understood.” The report also said that variants could affect a person’s immunity to a natural infection.

The highly contagious delta variant was not as prevalent in May and June but has since become the dominant strain in the U.S. At the time, the alpha strain was the most common.

The agency noted that the reinfection numbers “might be overestimated” since vaccinated people are “possibly less likely to get tested.”

Some members of Congress, including Sen. Rand Paul (R-Ky.), have said they do not plan to get the vaccine, citing claims that because they previously had COVID-19, they have immunity. 

“Until they show me evidence that people who have already had the infection are dying in large numbers or being hospitalized or getting very sick, I just made my own personal decision that I’m not getting vaccinated because I’ve already had the disease and I have natural immunity,” Paul said in May.