Pfizer, Moderna COVID-19 vaccines 94% effective at cutting hospitalizations for older adults, CDC says

Clinical trials already proved how effective Pfizer and Moderna’s vaccines are at stopping the spread of COVID-19, and that data was reaffirmed on Wednesday when the U.S. Centers for Disease Control and Prevention (CDC) revealed the results of its three-month real-world study of the two vaccines in patients 65 and older.

The CDC’s study found the shots are 94% effective at preventing hospitalizations for fully vaccinated adults and 64% effective among partially vaccinated adults 65 and older.

These numbers mirror what was revealed in clinical trials last year, which showed Pfizer’s vaccine is 95% effective and Moderna’s is 94.5%.

"These findings are encouraging and welcome news for the two-thirds of people aged 65 and up who are already fully vaccinated," said Dr. Rochelle P. Walensky, director of the CDC.

In this illustration, a syringe seen in front of the Moderna

In this illustration, a syringe seen in front of the Moderna, Pfizer and BioNTech logos. (Photo Illustration by Thiago Prudêncio/SOPA Images/LightRocket via Getty Images)

Between Jan. 1 and March 26, the CDC evaluated 417 hospitalized adults ages 65 and up at 24 hospitals in 14 states.

The CDC said 187 of them, the case-patients, had tested positive for coronavirus. The remaining 230 were in the control group and had tested negative.

Among the 187 case patients, 19 of them had received at least one shot of a two-dose vaccine more than 14 days before illness onset — meaning the vaccine was, at best, 64% effective.

And of that 19, just one of them had been fully vaccinated 14 days prior to falling ill.

The CDC said elderly people face an increased risk for severe outcomes from COVID-19, which is why they were among the first recipients of the vaccines when they rolled out in December and January.

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They said it was important to conduct the real-world study because hospitalizations were rare outcomes among clinical trial participants — meaning the trials had limited power to assess protection against severe COVID-19 among older adults.

"COVID-19 vaccines are highly effective and these real-world findings confirm the benefits seen in clinical trials, preventing hospitalizations among those most vulnerable. The results are promising for our communities and hospitals," Walensky said.

"As our vaccination efforts continue to expand, COVID-19 patients will not overwhelm health care systems – leaving hospital staff, beds, and services available for people who need them for other medical conditions."

This story was reported from Atlanta.