Blog post ignores important context of COVID-19 immunity study

A blog post claims that according to a study, people who were unvaccinated and previously infected with COVID-19 have better protection against the coronavirus than some fully vaccinated people.

“BOMBSHELL: The CDC agrees that natural immunity against prior infections is superior to vaccinated immunity alone,” said the January 19 after claimsciting a study by the federal health agency’s Centers for Disease Control and Prevention.

The post was flagged as part of Facebook’s efforts to combat fake news and misinformation on its News Feed. (Learn more about our Partnership with Facebook.)

The blog post gives the impression that vaccination against COVID-19 is not useful for people who have had the virus, and that previously infected people will be able to avoid hospitalization and death if they contract the virus again. COVID-19. But that ignores the limited scope of the study and dismisses the researchers’ conclusion – that vaccination can help prevent serious illness, hospitalization and death.

A prior infection with COVID-19 does not guarantee that a person will not need medical attention if they contract the virus again.

CDC study

The blog post cites a CDC study which looked at how people fared against the delta variant of COVID-19 between May and November 2021. The delta variant was first reported in India before heading to the United States in March 2021, according to the CDC.

Researchers looked at infection and hospitalization rates among four groups of people in New York and California:

  • Vaccinated people who had previously been infected with the virus
  • Vaccinated people who had not been infected before
  • Unvaccinated people who had previously been infected
  • Unvaccinated people who had not been infected before

The researchers found that people who had natural immunity to a previous COVID-19 infection were better protected against the virus during the delta-fueled surge than vaccinated people who had never been infected.

But the CDC issued several caveats about its analysis.

The CDC said it completed its study before the widespread spread of the more infectious omicron variant, “for which vaccine-derived or infection-derived immunity may be diminished.” The study also occurred when most people did not have access to a booster dose of the COVID-19 vaccine, which would provide Additional protection against the virus.

The study also had a limited sample size and did not include information on the severity of previous infections or the factor of death from the virus.

Vaccination against COVID-19 remains important

The main takeaway from the CDC study “clearly shows” that vaccination is the surest form of protection against COVID-19, and that it provides additional protection for people who have already been infected, said Dr. Erica Pan, state epidemiologist with the California Department of Public Health, tells PolitiFact.

“It shows that people who are still unvaccinated are most at risk of hospitalization and death,” she said. “Apart from this (CDC) study, recent data on the highly contagious omicron variant shows that getting a booster provides significant additional protection against infection, hospitalization, and death.”

Another CDC report, of October 2021, claimed that people infected with the virus should still get vaccinated. Vaccinations combined with previous infection provide stronger protection against serious disease, hospitalizations and death related to the virus than natural immunity alone.

A study of the Mayo Clinic found that unvaccinated people who have been infected before are twice as likely to contract the virus again as those who are fully vaccinated. During this time, a Johns Hopkins Medicine A study shows that a fully vaccinated person who has already been infected will have higher antibody levels that can help stave off another COVID-19 infection than an unvaccinated person who has had the virus.

Our decision

A blog post claims that “the CDC admits that natural immunity against prior infections is superior to vaccinated immunity alone.”

The post is misleading and omits key details.

CDC researchers found that during the outbreak of COVID-19 caused by the delta variant, unvaccinated people who had previously had the virus were less likely to get COVID-19 than fully vaccinated people who had never had it. disease. However, the study concluded that unvaccinated people are still at high risk of re-infection and that the best defense against the virus remains full vaccination.

The study was done before the surge of the omicron variant and before booster shots of the COVID-19 vaccine became widely available.

The statement contains an element of truth but ignores critical facts that would give a different impression. We rate it mostly wrong.

Comments are closed.