Two new studies find that updated boosters are more effective than the original vaccines at preventing infection and severe disease, almost a quarter of eligible Americans are not aware that they can get an updated booster, and more in this week's roundup of COVID-19 news.

• Updated bivalent boosters provide greater protection against symptomatic infection, as well as more severe COVID-19 outcomes, compared to the original monovalent vaccines, according to two new studies. In the first study, which was published in the New England Journal of Medicine, researchers from the University of North Carolina Gillings School of Global Public Health and the North Carolina Department of Health and Human Services analyzed data from the state's vaccine registry to compare the effectiveness of the bivalent booster to the original vaccine. Almost 300,000 people received the original vaccine over 99 days between May and August 2022, and over 1 million received the bivalent booster over 99 days from September to late November 2022. Overall, the researchers found that the bivalent vaccine was 58.7% effective against severe COVID-19 and 61.8% effective against severe infection that resulted in hospitalization or death. In comparison, the original vaccine was only 25% effective against severe COVID-19 and 24.9% effective against hospitalization or death. In a second study, which was published in CDC's Morbidity and Mortality Weekly Report, researchers analyzed data from COVID-19 tests conduced at pharmacies between Dec. 1, 2022, and Jan. 13, 2023. Overall, the researchers found that the bivalent boosters were similarly effective at preventing infection against the newer XBB and XBB1.5 omicron subvariants as different BA.5 subvariants. For people ages 18 to 49, the bivalent booster was 49% protective against symptomatic infection from XBB and XBB1.5 and 52% protective against infection from BA.5 subvariants. "So bottom line … is we did not see reduced vaccine protection against symptomatic illness for XBB and XBB.1.5, compared with those other recent BA.5 variants," said Brendan Jackson, head of CDC's COVID-19 response. "Quite reassuring." (Branswell, STAT, 1/25; AHA News, 1/25; Hein, MedPage Today, 1/25)

• Long COVID continues to keep a significant number of Americans out of the workforce, according to a new report from the New York State Insurance Fund (NYSIF). For the report, NYSIF examined 3,139 COVID-19-related compensation claims that were filed between Jan. 1, 2020, and March 31, 2022. Overall, the report found that roughly 31% of claims were from people with long COVID. Among these individuals, 71% said they had experienced symptoms that required treatment or kept them from working for at least six months. Forty percent of long COVID patients said they returned to work within two months of their initial infections but continued to receive treatment, and 18% of long COVID patients said they took over a year to return to work. "Long COVID has harmed the workforce," NYSIF wrote. "The report's findings have implications for the broader labor market and the economy. They highlight long COVID as an underappreciated yet important reason for the many unfilled jobs and declining labor participation rate in the economy, and they presage a possible reduction in productivity as employers feel the strains of an increasingly sick workforce." (Bean, Becker's Hospital Review, 1/25; Knutson, Axios, 1/24)

• In 2021, researchers found that fluvoxamine, a generic antidepressant, was able to significantly reduce the risk of hospitalization from COVID-19. In randomized clinical trial of nearly 1,500 patients in Brazil, patients who received fluvoxamine were 32% less likely to be hospitalized or need at least six hours of emergency care compared to patients who received a placebo. However, since then other large studies have not been able to confirm those results. In a new study published in JAMA, researchers tested fluvoxamine's efficacy among 1,288 COVID-19 patients ages 30 and older. Participants were randomly assigned to either a treatment or control group. Overall, the researchers found that there was no significant difference in recovery time between the treatment and control groups. Those who received fluvoxamine took a median of 12 days to recover from their COVID-19 infection compared to 13 days for those who received a placebo. In addition, participants in both the treatment and control groups required hospital, urgent care, or ED care at similar rates (3.9% vs. 3.8%, respectively). "These findings do not support the use of fluvoxamine at this dose and duration in patients with mild to moderate COVID-19," the researchers wrote. In an accompanying editorial, Adarsh Bhimraj, from Houston Methodist Hospital, and Jason Gallagher, from Temple University, noted that while fluvoxamine was "one of the more interesting" medications identified as a potential COVID-19 treatment, the "totality of evidence for fluvoxamine does not support its current use for treatment of mild to moderate COVID-19." (Hein, MedPage Today, 1/12)

• Almost a quarter of vaccinated U.S. adults have not received an updated bivalent booster because they are not aware they are eligible for an updated dose, according to a new study published in CDC's Morbidity and Mortality Weekly Report. For the study, researchers surveyed 1,200 U.S. adults who had been previously vaccinated against COVID-19 between Nov. 1-5, 2022, with a follow-up survey between Dec. 6-10, 2022. Overall, the researchers found that 396 participants had received a bivalent booster, and 714 participants had not. Among those who had not yet received a booster, 23.2% were not aware they were eligible for a bivalent booster, and 19.3% were not aware that a bivalent booster was even available. Another common reason participants gave (18.9%) for not getting an updated booster was they believed they already had sufficient protection from their previous vaccinations. After viewing information about the eligibility and availability of the updated boosters, 67.8% of participants who had not received the booster said they planned to do so in the future. However, in a follow-up survey a month later, only 28.6% of these participants had actually received a booster. According to the researchers, healthcare and public health professionals should provide people with more information about booster vaccination and waning immunity and work to increase access to the vaccines to improve overall booster rates going forward. Currently, CDC data shows that only 15% of the eligible U.S. population has received an updated booster. (Gallagher, Healio News, 1/21; Sinclair et al., Morbidity and Mortality Weekly Report, 1/20)

• FDA's Vaccines and Related Biological Products Advisory Committee (VRBPAC) on Thursday voted 21-0 to recommend the United States change its COVID-19 vaccine strategy, replacing initial doses of COVID-19 vaccines with the bivalent ones specifically aimed at targeting omicron subvariants. Most VRBPAC members were also supportive of FDA's plan to transition to a single annual COVID-19 vaccine for most Americans, which will be matched each year to different circulating strains of the coronavirus. However, other panel members said more information is needed before making such a recommendation. Panel members also voiced support for FDA holding an annual meeting to make a formal decision on which strains of the coronavirus the vaccine will target. "We can't keep doing what we're doing. We have to move on," said Bruce Gellin, chief of global public health strategy at the Rockefeller Foundation and a temporary voting member on VRBPAC. "I think this is a reasonable approach." (Gonzalez, Axios, 1/26; Hensley, "Shots," NPR, 1/26; Herper/Branswell, STAT, 1/26; Mueller/LaFraniere, New York Times, 1/26; Allen, Kaiser Health News, 1/27)