The omicron subvariant BA.5 now makes up more than 80% of all Covid-19 cases in the United States, a fall booster campaign could prevent up to 160,000 deaths, and more in this week's roundup of Covid-19 news.

• Roughly one in 20 people who have had Covid-19 experience long-term smell or taste dysfunction, according to a new study published in The BMJ. Researchers analyzed data from 18 studies that included 3,699 participants and used modeling to estimate how many people continued to experience smell or taste dysfunction at least six months their initial coronavirus infection. In total, the researchers estimated that 5.6% of Covid-19 patients (15 million people globally) had smell dysfunction for at least six months, and 4.4% (12 million people globally) had taste dysfunction. In addition, women were less likely to regain their sense of smell and taste than men, and people with more severe initial dysfunction and nasal congestion were less likely to regain their sense of smell. The researchers noted several limitations to their study, including the variable quality of the studies analyzed and the fact that dysfunction was based on self-reported data, which may overestimate recovery. The true number of people with continued olfactory dysfunction could be even higher. "Given that an estimated 550 million cases of covid-19 have been reported worldwide as of July 2022, large numbers of patients will be seeking care for these disabling morbidities," wrote Paolo Boscolo-Rizzo, from the University of Trieste in Italy, and colleagues in an accompanying editorial. " … Loss of smell and taste adversely affects quality of life by depriving those affected of several everyday pleasures and social bonds. People can also experience anorexia, food aversions, malnutrition, anxiety, and depression." (Falconer, Axios, 7/27; George, MedPage Today, 7/27)

• Hypertension may more than double the risk of hospitalization after infection with the omicron variant, even among individuals who are fully vaccinated and boosted, according to a new study published in Hypertension. For the study, researchers at the Smidt Heart Institute at Cedars-Sinai analyzed EHRs for 912 people who were fully vaccinated and boosted and had been diagnosed with Covid-19 between Dec. 1, 2021, and April 20, 2022—during the first omicron surge. Overall, 145 patients were hospitalized, and of these patients, 125 had hypertension. According to the researchers, hypertension was associated with a 2.6-fold increased risk of hospitalization from Covid-19. This is higher than all other identified risk factors, including chronic kidney disease, heart attack, and longer intervals between last vaccine dose and infection. "We were surprised to learn that many people who were hospitalized with COVID-19 had hypertension and no other risk factors," said Susan Cheng, director of the Institute for Research on Healthy Aging at the Smidt Heart Institute and the study's senior author. "This is concerning when you consider that almost half of American adults have high blood pressure." According to Joseph Ebinger, a clinical cardiologist and director of clinical analytics at the Smidt Heart Institute and the study's first author, "[t]he take-home message is that avoiding infection is extremely important—even when the circulating viral variant is presumed to cause mild disease in most people." (AHA News, 7/21; Cedars-Sinai news release, 7/21; Beusekom, CIDRAP News, 7/21)

• Long Covid affects more than just adults, as two separate studies found a significant number of children also experience long-term symptoms. In the first study, which was published in JAMA Network Open, researchers analyzed data from between March 7, 2020, and Jan. 20, 2021, from 39 pediatric EDs in eight countries within the Pediatric Emergency Research Network. The average age of patients was three years old, and 52.8% were male. Overall, 1,884 children were diagnosed with Covid-19. At a 90-day follow-up, 5.8% continued to report symptoms, including fatigue, cough, and shortness of breath. Among children who were hospitalized, this figure was higher, at 9.8%. In a separate study, which was published in Lancet Child & Adolescent Health, researchers from Denmark surveyed the guardians of 10,997 children who had tested positive for Covid-19 between January 2020 and July 2021, along with 33,016 children who did not test positive. Overall, children who had Covid-19- had a greater risk of experiencing at least one symptom that lasted more than two months than children who had not been infected. Some common symptoms included mood swings, trouble concentrating, and rashes. According to Selina Kikkenborg Berg, the study's lead author from Copenhagen University Hospital, further research on the long-term consequences of the pandemic on all children is needed before the window of opportunity closes. "The window for investigating long COVID is closing up," Berg said. "In my opinion, we desperately need clinical studies examining these children suffering from long-lasting symptoms who need symptom relief." (Short, MedPage Today, 7/22; Jenks, MedPage Today, 6/22)

• Opening a fall booster campaign to anyone who received their last Covid-19 vaccine at least five months earlier could potentially prevent more than 1 million hospitalizations and up to 160,000 deaths, according to a new report from the Commonwealth Fund. For the report, researchers created a simulation model to project the trajectory of Covid-19 cases, hospitalizations, and deaths if the United States completed a booster vaccination campaign in the early fall for anyone who had their last vaccine dose at least five months before. Assuming booster coverage in the fall mirrored influenza vaccination in 2020-2021, the United States could prevent almost 25 million infections, more than 1 million hospitalizations, and 101,858 deaths. Under a more ambitious scenario where 80% of eligible people get boosted in the fall, the United States could prevent over 48 million infections, roughly 1.7 million hospitalizations, and 159,827 deaths. However, if vaccination rates continue at their current pace through March 2023, a surge in Covid-19 cases in the fall could potentially lead to a peak of 1,500 deaths a day in December 2022. The researchers also noted that the "continued absence of new federal funding for COVID-19 vaccination will limit efforts to increase booster vaccination coverage and could lead to thousands of avoidable hospitalizations and deaths." (Bean, Becker's Hospital Review, 7/27; Melillo, "Changing America," The Hill, 7/26)

• The omicron subvariant BA.5, which is currently driving a new surge in infections across the United States, continues to grow in prevalence, according to CDC data. For the week ending July 23, BA.5 made up 81.9% of all new Covid-19 infections, while BA.4 made up 12.9%. In comparison, BA.2, which was the dominant coronavirus subvariant in the spring, now makes up for just 0.3% of all new infections. "We are in BA.5 mode," said Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases. Federal health officials are planning to authorize new boosters targeting BA.4 and BA.5 in the next few months, with Fauci saying that they are the "best guess" for dealing with the coronavirus in the fall. (Bean, Becker's Hospital Review, 7/26)