Research released Thursday and Friday reinforces data from clinical trials...

Research released Thursday and Friday reinforces data from clinical trials and from other countries that boosters greatly increase protection against serious illness and infection. Credit: AP/Nam Y. Huh

Vaccine booster shots dramatically reduce the chance of infection and hospitalization, even against the highly contagious omicron variant, according to newly released federal data, which found that an unvaccinated senior is 49 times more likely to be hospitalized with COVID-19 than someone 65 and older who received a booster.

Meanwhile, the state’s positivity rate fell below 10% for the first time since Dec. 20, said Gov. Kathy Hochul, who during an appearance on Long Island said she has not decided whether to extend the expiration date for a statewide mask or vaccine mandate past Feb. 1.

A Centers for Disease Control and Prevention analysis of hospitalization data in New York and 10 other states, along with three studies involving CDC researchers, provides the first extensive findings on how boosters affect U.S. hospitalizations.

The research, released Thursday and Friday, reinforces data from clinical trials and from other countries that boosters greatly increase protection against serious illness and infection.

One study, based on nearly 88,000 hospitalizations in 10 states — including New York — from Aug. 26 to Jan. 5, found that an adult with a booster shot was 94% less likely to be hospitalized during the time when the delta variant was dominant compared with unvaccinated adults. Adults with boosters were 90% less likely to be hospitalized while omicron has been dominant.

Two vaccine doses also provide significant protection, but that protection decreases over time, the study found. Those who received their second dose of vaccine more than six months earlier, but had not been boosted, were 57% less likely to be hospitalized during the omicron era.

Boosters also greatly reduce the chance of an emergency department or urgent care visit, the study found.

A separate analysis of hospital admissions in 11 states, including New York, focused on adults 50 and older who were hospitalized from Dec. 1 to Dec. 25, when the omicron variant became dominant.

The CDC found that the hospitalization rate for unvaccinated adults 50 to 64 is 44 times higher than for their boosted counterparts, and 49 times higher for seniors.

Dr. Steven Carsons, director of the Vaccine Center at NYU Langone Hospital-Long Island in Mineola, said he expected studies to show boosters kept many people out of the hospital.

"What is maybe a little surprising is how well these are working," he said, pointing to the large gap in hospitalization rates.

Even so, Carsons said, "In a way, this is unsurprising" because booster shots for all vaccines pump up the body’s immune system, which is why they are common for other diseases as well.

"This is not really a specific thing for the COVID vaccines," he said. "This is a principle of how our immune systems work."

Multiple studies show that effectiveness from vaccination against COVID-19 wanes over time, especially in those 65 and older.

Hochul: 'The trend is looking good'

Hochul on Friday said she likely will wait until Jan. 31 to announce whether to extend the Feb. 1 expiration date of a state mandate requiring people to wear masks or show proof of COVID-19 vaccination to enter indoor public places.

"I’ll tell you about Feb. 1 on Jan. 31," she said during a news conference at Brookhaven National Laboratory. "I really do need to wait until that time. The trend is looking good … and I’m an optimist. But I saw a very good trend just in early November, and then everything changed" when the omicron variant hit.

The decision will be based on the COVID-19 indicators at that time and what the near future looks like, she said.

Earlier Friday morning, in an address in Woodbury before hundreds of business leaders and lawmakers at a Long Island Association breakfast, the governor said she sees "the beginning of the end" and is "so excited to be able to soon be announcing the lifting of restrictions."

"We are looking forward to the day we can lift the school as well as the business requirements," she said in Brookhaven. " … That means we have turned the corner in a way that we don’t feel like we’re going to be sliding backward anytime soon."

Hochul said COVID-19 indicators are heading in the right direction after breaking records this month in New York State and on Long Island.

For the first time since Dec. 20, the statewide daily positivity level has fallen to single digits, hitting 9.75% on Thursday, she said.

"We are finally trending in the direction we want to go down, and that is downward," she said.

The statewide number of daily new cases has dropped by 66.6% in the two weeks since it hit a record 90,132 on Jan. 7, she said. On Thursday, the figure was 28,296.

She noted that Long Island is on the same trajectory, with a 75% drop from its peak of about 14,000 cases on Dec. 31 to about 3,500 now.

But the omicron surge is far from over, she said, and people should still be vigilant. Statewide, 154 people died on Thursday of causes linked to the virus, she said.

Hochul again urged New Yorkers to get boosted.

Nationwide, only 39.5% of those eligible for a booster dose have received one, according to the CDC.

Boosters dramatically reduce the likelihood of infection as well as severe illness, one of the studies released Friday found. In October and November, an unvaccinated adult was 13.9 times more likely to be infected, compared with people who had received boosters. In addition, an unvaccinated person was more than 53 times more likely to die of COVID-19, the study found.

Omicron’s dominance in December reduced the infection gap, but it remained high. An unvaccinated adult was 4.9 times more likely to be infected than an adult who received a booster shot, and 2.8 times more likely to be infected than a fully vaccinated adult without a booster. Boosters especially reduce risk for those 50 and older, the study found.

The study was based on an analysis of nearly 9.7 million COVID-19 cases nationwide from April 4 to Dec. 25, 2021.

Another study, posted on the JAMA website, found that boosters significantly reduced the chance of getting COVID-19 symptoms, although protection was higher against the delta variant than against omicron.

The CDC recommends a booster at least five months after receiving a Moderna or Pfizer-BioNTech shot, and two months after a Johnson & Johnson. Young children are not yet eligible for boosters, and adolescents ages 12 to 17 can get only a Pfizer booster.

With Candice Ferrette

Sign up to get text alerts about COVID-19 and other topics at newsday.com/text.

What to know

COVID-19 booster shots greatly reduce the chance of infection or hospitalization, even against the highly contagious omicron variant, new studies and analyses find.

Adults with booster shots were 90% less likely to be hospitalized than unvaccinated adults, during the time when omicron has been dominant, one study found.

New York’s positivity rate fell below 10% for the first time since Dec. 20, but Gov. Kathy Hochul said she wants to make sure the positive trend holds before lifting mask or vaccine mandates.

Latest videos