Research hailing the benefits of the COVID-19 shot keeps coming

Good health news for babies, kids and adults regarding the benefits of COVID-19 vaccination kept coming in December.

Pregnant people who were vaccinated before becoming infected with the coronavirus had a lower risk of severe COVID-19 — and their infants were less likely to be born prematurely — than pregnant people who had not gotten vaccinated before an infection. Researchers analyzed a Canadian health database of pregnant people diagnosed with COVID-19 from April 2021 to December 2022, covering the Delta and Omicron periods. Only 5 percent in Delta and 1.5 percent in Omicron of those vaccinated before diagnosis were hospitalized, compared with 13.5 percent and 5 percent of those who weren’t vaccinated. The percentage of newborns who were preterm was also lower for people vaccinated during pregnancy, researchers report December 15 in JAMA.

The 2024-2025 COVID-19 vaccine provided kids extra protection from the disease on top of their immunity from past years’ shots, infections or both. The vaccine was an estimated 76 percent effective against emergency department or urgent care visits for COVID-19–like illness in children nine months to four years old, compared with not getting the vaccine. That means 76 percent fewer of the vaccinated kids had emergency visits. The vaccine was an estimated 56 percent effective for kids five to 17 years old, researchers report December 11 in Morbidity and Mortality Weekly Report. The study looked at an electronic health network of nine U.S. states.

And a study of millions of people in France found that vaccinated adults had a lower risk of death from any cause. The analysis, using the French National Health Data System, included close to 23 million vaccinated and almost 6 million unvaccinated adults ages 18 to 59. From 2021 to 2025, there were around 98,500 deaths in the vaccinated group and about 32,500 deaths in the unvaccinated group. That corresponded to a 25 percent lower risk of dying for any reason for those vaccinated, researchers report in the December 4 JAMA Network Open.

It’s not too late to get vaccinated against COVID-19. Cases tend to ramp up as winter progresses. Only 7 percent of kids and 15 percent of adults have gotten the 2025-2026 shot so far in the United States, a decrease from previous years. That could be in part because health officials in the Trump administration have restricted access to the latest COVID-19 vaccine.