A new study on the effects of natural infection by the coronavirus suggests that there may be little to no benefit for recovered SARS-CoV-2 patients in receiving vaccines against the coronavirus.
According to the study, conducted in Cleveland, Ohio and published in the MedRxiv journal last month, people who were infected with the coronavirus enjoy significant long-term immunity from the virus, which is unlikely to be increased by being injected with one of the coronavirus vaccinations now on the market.
The study followed 52,238 employees of the Cleveland Clinic Health System, monitoring infections among vaccinated and unvaccinated workers, and the incidents of reinfection among both vaccinated and unvaccinated workers.
Of the 52,238 employees tracked in the study, 2,579 had previously tested positive for the coronavirus, while 49,659 had never been confirmed as carrying the virus.
Fifty-three percent of the 2,579 employees who had been infected with the virus previously remained unvaccinated (1,359 people), compared to 41% (22,777) of the employees who were never diagnosed with the virus.
Zero previously infected employees were reported to have become infected again with the virus, regardless of their vaccination status.
Vaccination significantly reduced the risk of coronavirus infection, the study found, but only among those who had not previously been infected.
The authors concluded that vaccination after natural infection is unlikely to have any benefit for recovered COVID patients.
“Individuals who have had SARS-CoV-2 infection are unlikely to benefit from COVID-19 vaccination, and vaccines can be safely prioritized to those who have not been infected before.”
More recent data collected by the Israeli Health Ministry in the midst of outbreaks of the Delta Variant found that there were far fewer cases of reinfection after natural infection than there were infections among vaccinated Israelis who had never been diagnosed with the virus previously.
With a total of 835,792 Israelis known to have recovered from the virus, the 72 instances of reinfection amount to 0.0086% of people who were already infected with COVID.
By contrast, Israelis who were vaccinated were 6.72 times more likely to get infected after the shot than after natural infection, with over 3,000 of the 5,193,499, or 0.0578%, of Israelis who were vaccinated getting infected in the latest wave.