Updated booster shots have boosted Americans’ defenses against severe Covid and reduced the risk of hospitalization by about 50 percent compared to certain groups vaccinated with the original vaccines, the Centers for Disease Control and Prevention reported in two studies released Friday .
The research represents the agency’s first look at how the reformulated boosters, tailored to protect against new Omicron variants, work in preventing serious outcomes of infection with the virus, including emergency room visits and hospitalizations.
Federal health officials are urging Americans to get the updated booster shots in hopes of reviving a delayed vaccination campaign. So far, however, less than a fifth of American adults and just a third of people age 65 and older have received updated immunizations, reflecting a retreat in many parts of the country from the more aggressive vaccination campaigns early in the pandemic.
New virus variants that are better at evading the immune system have gained prominence, and the number of Covid cases and hospital admissions has risen in recent weeks. On average, about 375 Americans die each day, a 50 percent increase in the past two weeks. Older people are particularly hard hit.
The virus has exacerbated the difficulties facing a healthcare system already burdened by the resurgence of influenza and respiratory syncytial virus after two years of decline in these infections.
Read more about the coronavirus pandemic
- Free home tests: With cases surging, the Biden administration has restarted a program that has delivered hundreds of millions of tests through the mail service.
- Updated recordings: The Food and Drug Administration extended eligibility for the updated coronavirus boosters to children as young as 6 months of age.
- Infection: Like a zombie in a horror movie, the coronavirus can survive long after death in infected patients and even spread to others, according to two startling studies.
- Pregnant woman: Although studies have shown that the Covid vaccine is safe for expectant women, many have avoided vaccination, unaware of the risks the virus poses.
Even though federal health authorities encourage testing and the use of masks in certain settings, in practice precautionary measures have become far less common. Antiviral drugs against Covid are still difficult to find for many infected people.
“We probably won’t see Covid waves like we’ve seen in the past, which is good, but that doesn’t mean people aren’t still dying and that those lives couldn’t still be saved if we got more shots in guns,” he said dr David Dowdy, an epidemiologist at the Johns Hopkins Bloomberg School of Public Health.
A CDC study released Friday looked at how the updated gunfire protected people in seven health systems from Covid-related emergency room visits and hospitalizations.
The study, which looked at about 15,000 hospital admissions, spanned from mid-September to mid-November, when Covid cases were mostly caused by the BA.5 Omicron variant – the target in part of the reformulated shots.
Since then, however, more evasive versions of Omicron known as the BQ.1 and BQ.1.1 have become more common, and it’s not clear how relevant the conclusions are to the newer variants.
During the BA.5 period, people who received the updated booster shots had a 57 percent reduced risk of hospitalization compared to unvaccinated people, a 38 percent reduced risk compared to people who had recent doses of the original vaccine had received, and a 45 percent lower risk compared to people whose last dose of the original vaccine was at least 11 months ago.
However, the CDC’s study did not take into account whether patients had previously been infected with the virus, which may make the updated vaccines appear less effective than they are. And the research didn’t consider whether certain groups were more likely to receive treatments like Paxlovid, which may have skewed the results.
A second study reported on the benefits of updated booster shots for older Americans in 22 hospitals from early September through late November.
For people aged 65 and over, the updated vaccines reduced the risk of Covid hospitalization by 84 percent compared to unvaccinated people and by 73 percent compared to people who had received at least two doses of the original vaccines.
CDC scientists said the higher vaccine efficacy estimates in older age groups may reflect a variety of differences in the particular patient groups studied.