A new CDC study shows unvaccinated Americans who previously had COVID-19 were five times more likely to get it again than their fully vaccinated peers.
A new study released by the Centers for Disease Control and Prevention on Oct. 29 provides more evidence for the strong benefits of vaccination against COVID-19, even among those Americans who previously contracted and recovered from the virus.
The study, released as a part of the agency's Morbidity and Mortality Weekly Report, drew on data from dozens of researchers across 187 hospitals in nine states. Among 7,000 individuals who were hospitalized with COVID-like illnesses over the past nine months, as the highly contagious delta variant became the predominant strain in the United States, the researchers found that unvaccinated patients were 5.49 times more likely to test positive for COVID-19 than their fully vaccinated peers, even if they had previously been infected with and recovered from the coronavirus.
"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 on the study's findings. "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."
The CDC findings blow a hole in an increasingly popular claim from some Republican lawmakers and anti-vaccine activists that so-called "natural immunity" to COVID, acquired from a previous infection, is akin to or better than the protection offered by vaccination. In September, a group of 15 lawmakers in the GOP Doctors' Caucus sent a letter to the CDC urging the agency to "recognize natural immunity."
Just last week, a group of those lawmakers wrote to President Joe Biden asking that he "revise the Administration's policy to provide Federal employees the ability to test-out from any vaccination requirement if they can demonstrate natural immunity to the disease." Representatives for Reps. Andy Harris (R-MD) and Brad Wenstrup (R-OH), two co-chairs of the caucus, did not respond to inquiries about whether the lawmakers stand by their request given the latest CDC findings.
Public health officials say dubious claims about the supposed benefits of natural immunity are detrimental to the U.S. vaccination campaign and could exacerbate noncompliance with vaccine mandates. In New York City, for example, officials are worried about a possible shortage of police, firefighters, and other first responders as almost one-tenth of city employees remained unvaccinated after a deadline of 5 p.m. on Oct. 29 to demonstrate proof of vaccination. The belief that natural immunity should count as equivalent to vaccination was frequently cited by anti-mandate protesters, the Associated Press reported.
Though the latest study bolsters previous CDC findings on the benefits of vaccination for previously infected Americans, an Israeli preprint study published online in August before peer review appeared to show the opposite: that natural immunity actually conferred stronger and longer-lasting protection against COVID infection than did vaccination. That study was frequently cited by advocates for natural immunity protections.
The CDC researchers noted the Israeli study relied on cohort data from any positive COVID test result, while the CDC analysis only considered laboratory-confirmed tests in hospital settings. They added that the Israeli researchers considered patients who had been vaccinated more than six months prior to their positive test, postulating that more recent vaccinations within the American data could account for that discrepancy.
In a press briefing on Wednesday, National Institute of Allergy and Infectious Diseases Director Dr. Anthony Fauci, who also serves as Biden's chief medical adviser, spoke of yet another reason for all Americans to get vaccinated: protection against long-term COVID symptoms. According to one study, over one-third of COVID survivors reported at least one symptom of so-called "long COVID" such as fatigue, dizziness, or "brain fog."
Fauci pointed to a recent study published in the Lancet Infectious Diseases that showed that those who'd been vaccinated were half as likely to report long COVID symptoms if they became reinfected as those who were unvaccinated — "Another reason why it is so important to get vaccinated," Fauci said.
Americans interested in getting vaccinated — be it their first, second, or booster dose — can go to vaccines.gov to schedule an appointment.
Published with permission of The American Independent Foundation.