Although updated Covid-19 vaccines won’t offer complete protection against a trip to hospital or emergency care, they do offer significant defense against the virus, especially for the elderly, according to two news reports. studies.
“Both studies show that bivalent booster has a pretty big benefit in that it adds a lot of extra protection against hospitalization due to Covid-19,” said Ruth Link-Gelles, epidemiologist at the Centers for Disease Control and Prevention of the United States. co-author of one of the studies. The studies published Friday in the CDC’s Morbidity and Mortality Weekly Report.
Bivalent boosters made by Moderna and Pfizer/BioNTech target the original strain of coronavirus and the Omicron BA.4 and BA.5 subvariants. Snapshots became available in early September.
Bivalent boosters appear to offer strong protection – up to 84% – against hospitalizations for the elderly. When the analysis included younger adults, they provided moderate protection against needing to go to the emergency room or hospital.
In one study, which included adults aged 65 and older who did not have compromised immune function and who had been hospitalized with Covid-19, researchers estimated that bivalent boosters were 84% effective against hospitalization with compared to those unvaccinated, and 73% effective in preventing hospitalizations compared to two or more doses of the original Covid-19 vaccines.
The study drew its data from 798 patients who were admitted to 22 hospitals in 18 states between September 8 and November 30.
Adults aged 65 and over have historically been among the most vulnerable to Covid-19, and current hospitalization data shows seniors are once again the hardest hit in the latest wave of Covid-19 cases. This wave is dominated by BQ.1 and BQ.1.1, descendants of BA.5. While hospitalizations have started to rise for all age groups, they are rising faster for the elderly.
Although 94% of older adults have completed at least their first round of Covid-19 vaccinations, CDC data shows that only about 36% of this age group have received an updated booster.
Dr. Paul Offit, who directs the Vaccine Education Center at Children’s Hospital of Philadelphia, said the findings suggest the Biden administration should focus on vaccinating those at high risk.
“What the administration should be doing is pushing for vaccination of people in high-risk groups, including the elderly, those who are immunocompromised and those with comorbidities. I think we’re all okay with that,” he said.
Offit said he remains unconvinced by the idea of continuing to stimulate otherwise young and healthy adults. “I still don’t see this as a public health strategy,” he said.
Many Americans agree. According to recent survey data collected by the Kaiser Family Foundation, even among those who received their first round of Covid-19 vaccines, more than 60% said they “don’t think they need the new booster” or ” don’t think the benefit is worth it.
A second CDC study released Friday included younger adults and examined the effectiveness of updated reminders in preventing emergency care and emergency department visits, as well as hospitalizations, in a nine-state hospital network. The study included more than 78,000 urgent care and emergency department visits and more than 15,500 hospitalizations. People who came to the hospital for treatment were eligible to be included in the study if they were over 18, had tested positive for Covid-19 and had no compromised immune function.
Compared to those who were not vaccinated, those who received an updated booster were 56% less likely to seek emergency or emergency room care and 57% less likely to be hospitalized.
Compared to those who had been vaccinated but had received their most recent dose 11 months or more earlier, updated reminders reduced the risk of being seen in the emergency room or urgent care by 50% and reduced the risk 45% hospitalization.
Compared to those who had recently received a booster with the original vaccines – two to four months previously – those who received updated boosters were 31% less likely to need to go to the emergency room or urgent care . The study did not provide an estimate of hospitalizations among people who recently received a booster with the original vaccine.
These are early studies. At the time they were done, only about 5% of adults in each study had received a bivalent booster.
That means the vaccine effectiveness of the booster is likely to be underestimated, the researchers told CNN. Normally, the people who get a booster the fastest are those who know they really need it because of an underlying condition or something else that they think puts them at higher risk.
These people are also more likely to need clinic or hospital care if they catch Covid-19, Link-Gelles said.
“What happens in the nature of these early evaluations is that sometimes we see this where the efficacy of the vaccine may be a little lower than we expected against more severe ends of the spectrum,” a- she declared.
“I think it’s likely that we’ll see the numbers, the vaccine effectiveness estimates for young adults, go up a bit.”
Experts who were not involved in the studies say they emphasize the need for all adults to get their boosters updated but also for people to use additional tools, including masks, ventilation and tests, for even stronger protection.
“It’s a reminder of what we’ve been saying now for several months, that we need to stop this idea of saying two vaccinations is one full vaccination,” said Dr. Peter Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine in Houston. “You need your booster, and you need your booster every four to six months because the protection even against hospitalization starts to wane.”
The study results come as federal officials announced a meeting to rethink the nation’s Covid-19 vaccines.
The US Food and Drug Administration plans to hold a meeting of its vaccine advisers on January 26 to consider if and how the composition of primary doses of Covid-19 vaccines should be changed and how the composition and timing of boosters should be changed. be adjusted in the future. . Representatives from the CDC and the National Institutes of Health will also participate in the discussion.