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New Studies Show Power of Booster Dose Against Omicron

Booster offers critical protection against severe COVID-19

January 21, 2022

Booster doses of the mRNA COVID-19 vaccines were 90 percent effective to prevent hospitalization due to the Omicron variant, according to a new report released today.

The Centers for Disease Control and Prevention’s (CDC) new Morbidity and Mortality Weekly Report included two studies evaluating the value of booster doses during the recent COVID-19 surges.

In a multistate analysis from late August through early January, researchers found that a third dose of the mRNA vaccine was at least 90 percent effective at preventing COVID-19–associated hospitalizations due to the Delta (94%) and Omicron (90%) variants. The third dose is critical to restore the protection that wanes over time, said Dr. Rochelle Walensky, CDC director.

“As we continue to face the Omicron variant—representing over 99 percent of infections in the United States today—I urge all who are eligible to get their booster shot to get it as soon as possible,” Dr. Walensky said.

A second report released today indicated that unvaccinated adults were at five-times higher risk of infection during December compared to adults who had received a booster dose. The nation’s public health leaders said the data reflects the importance of getting the booster dose when you are eligible.

“Overall those who received a booster dose had the most protection against emergency room visits, urgent care clinic visits, and hospitalizations,” Dr. Walensky said during a briefing today.

This month, the CDC is emphasizing:

  • Those who remain unvaccinated are at significantly higher risk for infection and severe disease from COVID-19
  • Protection against Omicron is highest for those who are up to date on their vaccinations

In Pennsylvania, more than 3.2 million people have received booster doses, according to CDC data. This represents about 38 percent of the fully vaccinated population.

The nation’s public health leaders said they are seeing reports of declining COVID-19 case rates in some northeast states, while other regions of the country continue to report increasing cases. The U.S. is averaging 744,600 daily cases, a 5 percent decrease from last week.

In Pennsylvania, there are 6,794 patients hospitalized with COVID-19, including 1,106 in the intensive care unit and 647 on ventilators. The state Department of Health reported 18,955 additional cases of COVID-19 today.

HAP strongly encourages everyone to get vaccinated against COVID-19 and receive a booster dose when they are eligible. A CDC guide about getting your booster dose is available online.