Updated Covid boosters cut the infection risk from XBB.1.5 subvariant by nearly half, CDC finds


The Updated Covid boosters almost halve the risk of contracting Covid from the major omicron subvariant. According to preliminary data released. By the Centers for Disease Control and Prevention on Wednesday.

In adults up to age 49, the latest boosters. From Pfizer-BioNTech and Moderna were 48% effective against symptomatic infections. From the XBB.1.5 subvariant, the new report said. As of January 21, this subvariant accounts for about 1 in 2 new cases in the United States.

Protection was lower in older groups: boosters were effective in 40% of adults aged 50 to 64 and 43% in those aged 65 and older.

Dr. Brendan Jackson, head of the CDC’s Covid response, said in a call. With reporters Wednesday that the results were “quite reassuring.” “These updated vaccines are protecting people against the latest Covid-19 variants.”

The Covid boosters were modified over the summer to target the BA.4 and BA.5. Omicron subvariants in addition to the original strain of the coronavirus. First identified in Wuhan, China in 2019.

BA.5 was the dominant variant in the US in the fall, but now accounts for only 2% of new cases.

As of last Wednesday, only 15% of people in the United States. Had received an update booster, according to CDC data.

“With these data, we can see there is a benefit that might convince some people. To sign up and get the bivalent booster,” said Dr. Peter Hotezo-directo. And dean of the Vaccine Development Center at Texas Children’s Hospital. National School of Tropical Medicine at Baylor  College of Medicine in Houston.

The CDC report is based on test results from more than 29,100 adults with boosters Covid symptoms. Who were tested at pharmacies nationwide from Dec. 1 to Jan. 13.

Updated Covid boosters cut the infection risk from XBB.1.5 subvariant by nearly half, CDC finds

People who were vaccinated but did not receive an updated booster were subvariant compared with those who had received. An updated booster in the previous two to three months. Those who did not receive the updated booster. Had their last vaccine dose about 13 months ago, Ruth Link-Gales. Who heads the CDC’s vaccine efficacy program, said on the call.

The protection provided by the booster is generally similar to that seen with the flu vaccine. Flu vaccine effectiveness varies from season to season. But shots reduce the risk of flu by 40% to 60%, according to the CDC.

Dr. Greg Poland, director of the Mayo Clinic Vaccine Research Group. In Rochester, Minnesota, cautioned that the CDC’s estimate of updated boosters may be an overestimate.

Those who received the updated booster were probably “much more likely. To wear masks indoors or limit their travel or not go to indoor restaurants,” he said.

He also noted that the CDC data does not capture people who were vaccinate. With the updated booster but were asymptomatic. Or who were sick enough to go to the hospital.

Hotez said that while the CDC results look subvariant promising, he wants. To see data on how well the perform against symptomatic infections after five or six months.

He said he would like to see more data on how well the updated boosters work against hospitalizations.

Jackson, of the CDC, said on the call that the agency is releasing data later Wednesday showing that the updated boosters. Cut the risk of death from Covid by about thirteen times compared to unvaccinated people.

He said the data also showed that those who received the updated booster had. Amore than double the rate of death from Covid compared to people who did not receive the vaccine.

The CDC report comes a day before a Food and Drug Administration advisory committee meeting. subvariant To discuss simplifying the Covid vaccination schedule.

In a document posted online Monday, the FDA proposed using the bivalent formula. In all Covid vaccines going forward, not just booster shots.

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