Research conducted by US-based scientists has revealed that those previously infected by COVID-19 do not get additional benefits from vaccination, reports News Medical.

The big picture: Conducted on 52,238 employees in Cleveland Clinic, the participants received two doses of the Pfizer/BioNTech or Moderna COVID-19 vaccine and were considered vaccinated after 14 days of receiving the second dose.

  • Participants with a positive RT-PCR test at least 42 days before the vaccination were considered previously infected.

Findings: Out of all infections, 99.3% occurred in participants who had never had COVID-19 and remained unvaccinated. Only 0.7% of infections occurred in participants who’d not contracted COVID-19 and had received the vaccine.

  • Notably, "not a single incidence of SARS-CoV-2 infection was observed in previously infected participants with or without vaccination," the study found.
  • All previously infected (regardless of being vaccinated) and currently vaccinated participants displayed a lower incidence of COVID-19 infection than previously uninfected and currently unvaccinated participants.

The bottom line: It was concluded that vaccination reduced the risk of a COVID-19 infection in previously uninfected participants but not in previously infected participants.

  • A prior COVID-19 infection offered protection against the virus for at least 10 months after the onset of symptoms or a positive test result, the study observed.

Yes, but: The Centers for Disease Control and Prevention (CDC) recommends vaccinating even those who've previously contracted the virus since "there is a chance - however rare - that one can be infected with the virus that causes COVID-19 again," as per Healthline.

  • Experts agree, pointing out that some people who have COVID don’t develop an immune response at all. In such cases, people can get "quite sick” if reinfected.