Vaccination is over five times more effective at preventing COVID-19 than immunity acquired by contracting and recovering from the virus, according to a new study from the Centers for Disease Control and Prevention (CDC).
The study, published Friday in the CDC journal Morbidity and Mortality Weekly Report found that vaccine-induced immunity was 5.49 times more protective than immunity from infection. The study analyzed data from the VISION Network, which includes 187 hospitals across nine states. The results contradict an Israeli study released in August, which found that those who had previously been infected with COVID-19 were significantly less likely to become infected with the Delta variant than the vaccinated.
"We now have additional evidence that reaffirms the importance of COVID-19 vaccines, even if you have had prior infection," CDC Director Dr. Rochelle Walensky said in a statement. "This study adds more to the body of knowledge demonstrating the protection of vaccines against severe disease from COVID-19."
"The best way to stop COVID-19, including the emergence of variants, is with widespread COVID-19 vaccination and with disease prevention actions such as mask wearing, washing hands often, physical distancing, and staying home when sick," Walensky added.
The vaccines included in the study were the mRNA shots produced by Moderna and Pfizer/BioNTech. Results aligned with other recent research showing that the Moderna vaccine was somewhat more effective at preventing infections, although both vaccines offered significant protection and each were superior to natural immunity. The Johnson & Johnson vaccine was not included in the study.
The Israeli study was sometimes cited by vaccine opponents as evidence that so-called "natural immunity" was superior to immunity from vaccines. Regardless of the level of protection, medical experts have nearly uniformly advised against reckless suggestions of becoming intentionally infected to acquire immunity. Over 740,000 people in the U.S. have died from COVID-19. The CDC has not determined that any deaths have been caused by COVID-19 vaccinations, although a small number of deaths are still being investigated and serious reactions do occur rarely.
Researchers suggested that the discrepancy between the new study and the Israeli research could be explained by differences in testing methods and in the timing of the vaccinations. The Israeli study included any positive COVID-19 test results, while the CDC study only included positive test results from individuals who were hospitalized in the VISION Network.
The CDC study was also focused on immunity in a period of between three and six months after vaccination or infection. The Israeli study only included vaccinations that had occurred six months earlier. CDC researchers noted that immunity "could be affected by time."
Newsweek reached out to the CDC for comment.
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Newsweek is committed to challenging conventional wisdom and finding connections in the search for common ground.
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