CDC: Boosters reduce COVID death risk 20-fold compared to unvaxxed

WASHINGTON (TND) — Those who received COVID-19 booster shots were 20 times less likely to die than the unvaccinated in October, according to new data, and federal officials expect vaccines and boosters will continue to protect against severe outcomes even if the spread of the omicron variant drives a spike in breakthrough infections in the United States.

“The more people get vaccinated, the less severe this omicron outbreak will be,” Jeffrey Zeints, coordinator of the White House COVID-19 task force, said Friday. “One hundred sixty thousand unvaccinated people have already needlessly lost their lives just since June, and this number will continue to go up until the unvaccinated take action.”

The Centers for Disease Control and Prevention updated its vaccine effectiveness data Friday to reflect COVID-19 infections through Nov. 20 and deaths through Oct. 30. According to the latest figures, the vaccinated had a fivefold lower risk of infection and a fourteenfold lower risk of death in October, and the boosted were 10 times less likely to get infected than the unvaccinated.

The numbers also indicate a considerably lower risk of infection or death for those who have gotten boosters compared to those who only received their initial doses of vaccines. In late October, infection rates for the boosted were about 2.5 times lower than the vaccinated without boosters, and death rates were nearly four times lower.

“If we're going to deal with omicron successfully, vaccinated people need to get boosted,” Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said on NBC’s “Meet the Press” Sunday. “And obviously, people who are not vaccinated clearly need to get vaccinated now more than ever.”

CDC data lags at least a month behind real-time, but more recent state-level breakthrough numbers reflect similar trends. Even as infections among the vaccinated have become more common, they are far better protected against serious illness than the unvaccinated and boosters can significantly strengthen immunity.

“The data validates our understanding of the effectiveness of vaccines in preventing symptomatic infection and severe disease against the delta variant,” said Dr. Gregory Schrank, an infectious disease expert at the University of Maryland. “With the delta variant’s mutations, we saw a reduction in the ability of our immune system’s antibodies to bind to the virus and prevent it from causing an infection and symptoms.”

The Wisconsin Department of Health Services reported last week that people who were not fully vaccinated in the state were five times more likely to be diagnosed with COVID-19 in November, 11 times more likely to be hospitalized, and 12 times more likely to die. The infection rate among the vaccinated was up by over 50% compared to October, though.

Since early October, about 25% to 30% of new infections in Missouri each week have been breakthrough cases. Only about 0.02% of the vaccinated have died, and nearly 95% of fatal breakthrough cases have involved patients with underlying medical conditions like chronic kidney disease, diabetes, or heart disease.

According to the Michigan Department of Health, the unvaccinated had a 4.3 times higher risk of infection than the fully vaccinated in October and 13.2 times higher risk of death. Through Dec. 3, about 2.4% of the state’s vaccinated population had been infected and 0.03% had died.

The most recent figures from the South Carolina Department of Health and Environmental Control show the unvaccinated accounted for 75% of cases and more than two-thirds of deaths and hospitalizations in the state between Oct. 16 and Nov. 15. Fewer than 1% of the vaccinated population have gotten a confirmed breakthrough infection.

In New York, where cases began to surge upward in early November, Department of Health records show vaccine effectiveness held steady around 80% against infection and 95% against hospitalization through the week of Nov. 22. It is not yet clear if that trend has shifted at all as new cases in the state climbed to record levels over the last week.

Notably, nearly all of these numbers pre-date the arrival of the omicron variant, which has proven far more capable than previous mutations of evading vaccine-induced immunity in other countries. However, officials and experts say there is strong evidence from South Africa and elsewhere that those who have been vaccinated or previously infected are less likely to experience serious symptoms from omicron if they get infected.

“We’ve seen cases of omicron among those who are both vaccinated and boosted, and we believe these cases are milder or asymptomatic because of vaccine protection,” CDC Director Dr. Rochelle Walensky said at a White House briefing Friday.

Experts are still uncertain if the omicron variant inherently causes less severe disease or if the populations it hit first had a high degree of existing immunity. Either way, the fact that cases requiring intensive care treatment are down 80% relative to past waves in South Africa offers some cause for cautious optimism.

“Even though we're still getting infected because this is spreading through immune evasion, it's spreading by evading the immunity that we've acquired,” Dr. Scott Gottlieb, former commissioner of the Food and Drug Administration, said on CBS’ “Face the Nation.” “We have some baseline immunity that protects us from getting very sick.”

Moderna announced Monday preliminary data shows its currently authorized half-dose booster shot increased antibody levels against the omicron variant 37-fold, and a third full-dose shot would increase antibodies 83-fold. Researchers have not determined how effectively those enhanced antibody levels actually protect against infection, but the company suggested health agencies consider increasing the recommended booster dose.

Pfizer has cited similar findings that a booster shot of its mRNA vaccine can increase neutralizing antibodies 25-fold compared to the first two doses. The company has also indicated the omicron variant might not reduce the protection against severe disease afforded by vaccine-induced T cells from the initial doses.

“While omicron means that having a large number of coronavirus infections is now inevitable, vaccines mean seeing a correspondingly large number of hospitalizations and deaths is optional,” Dr. Jay Varma, an epidemiologist at Weill Cornell Medicine, wrote in a New York Times op-ed Monday.

Much is still unknown about how omicron might spread as it becomes more prevalent in the U.S., but between its increased transmissibility and waning protection from vaccines, experts anticipate a significant uptick in infections among the vaccinated in coming weeks. They have stressed, however, that this should not undermine the rationale for getting vaccinated or boosted.

“Newly diagnosed infections will continue to rise amongst unvaccinated and the vaccinated – especially in areas of the country where booster uptake has been lower,” Schrank said. “We do not yet have enough data to understand how vaccination, including booster doses, impacts a person’s contagiousness with the omicron variant should they be infected.”

Tens of millions of Americans who have received vaccines got their initial doses too recently to be eligible for boosters under current federal guidance. Officials say those who cannot get boosted yet can have confidence they are protected against severe illness or death, but they should also practice proven mitigation strategies to minimize their risk of infection.

“People think that vaccine is the answer to everything,” Fauci told CNN Sunday. “We can't do it without vaccines, but we can do a lot more with other things.”