FDA extends the Johnson & Johnson vaccine's shelf life by six months; new CDC findings suggest possible, but rare, link between mRNA vaccines and myocarditis; and more.

• A work group of CDC's Advisory Committee on Immunization Practices in a report published this month said that, although "rare," myocarditis and pericarditis—inflammation of the heart muscle or the tissue around the heart, respectively— are occurring at higher-than-expected rates among young people, especially men, after they receive their second dose of the Pfizer-BioNTech or Moderna Covid-19 vaccines. According to CDC, the cases have happened more often among adolescent and younger men, between the ages of 16 and 24, and that most who were affected and "received care responded well to medicine and rest and quickly felt better." CDC is still exploring whether the cases are related to the vaccines, and the agency still recommends people get vaccinated, noting the risks posed by Covid-19 outweigh the potential side effects of any authorized vaccine (Cohen, CNN, 6/9; Tanner/Neergaard, Associated Press, 6/4; Heller, Reuters, 4/2; Kelley, The Hill, 6/4)

• FDA has authorized a new, more readily administered version of Regeneron Pharmaceuticals' Covid-19 antibody drug, called REGEN-COV. Previously, the drug had to be administered by intravenous infusion, but under the new authorization, providers can now administer it via simple injection when an IV infusion isn't possible or could postpone treatment. In addition, FDA's new authorization permits the drug to be mixed in a single vial rather being stored in separate vials, which could cut down the amount of time it takes for providers to prepare the medication. The authorization also allows providers to use a lower dose of the drug—roughly half the original dose—which could increase the number of available doses. Regeneron said it plans to deliver a minimum of one million doses to the federal government by June 30 (Walker, Wall Street Journal, 6/4).

• Pfizer-BioNTech and Moderna said they are currently testing their Covid-19 vaccines among children 12 and under, which means they could seek FDA's emergency use authorization (EUA) for the vaccines' use among children as early as September. Specifically, Pfizer said on Tuesday that it was testing its vaccine among children ages five through 12, and that it would start testing its vaccine in infants as young as six months in the coming weeks. According to Pfizer spokesperson Kit Longley, the company plans to apply for an EUA for the vaccine's use among children ages five through 11 in September, followed shortly afterwards by authorization for children ages two through five and then by children six months through two years in October or November. Similarly, Moderna said it expects results on its trials for its vaccine among children until the fall (Mandavilli, New York Times, 6/8).

• FDA on Thursday said the shelf life for Johnson & Johnson's Covid-19 vaccine could be extended by an additional six weeks. According to the New York Times, the announcement gives states additional time to determine how best to use the "millions of [J&J] doses" that were set to expire this month. "The decision is based on data from ongoing stability assessment studies, which have demonstrated that the vaccine is stable at 4.5 months when refrigerated at temperatures of 36 – 46 degrees Fahrenheit," J&J said in a statement (Weiland, New York Times, 6/10; O'donnell, Reuters, 6/8).

• The federal government has agreed to pay Merck about $1.2 billion for 1.7 million courses of the company's experimental treatment for Covid-19 so long as the therapy is proven to work in an ongoing clinical trial and receives an EUA from FDA. Merck is currently testing the therapy—an oral antiviral treatment called molnupiravir—in a late-stage trial among non-hospitalized patients to see whether the treatment lowers the risk of hospitalization or death. According to HHS, data from the trial is expected in the fall (Reuters, 8/9).

• J&J's Covid-19 vaccines produces diverse immune responses that enable the vaccine to effectively protect against multiple variants of the virus, according to a new study published Wednesday in Nature. The study, published as an accelerated article review, examined the antibody and cellular immune response among 20 volunteers. It found that the vaccine produced immune responses—including neutralizing antibodies and T-cells—against the original Covid-19 strain, as well Alpha, the variant first identified in the United Kingdom; Beta, first identified in South Africa; Gamma, first identified in Brazil; and Epsilon, first identified in the United States (Coleman, The Hill, 6/9; Weintraub, USA Today, 6/9; Palca, "Shots," NPR, 6/9).

• People who received AstraZeneca's vaccine appeared to have a slightly higher risk of a bleeding disorder and potentially several other rare blood issues, according to research published on Wednesday in Nature Medicine. For the study, researchers assessed 2.53 million adults in Scotland who had received at least one dose of either AstraZeneca's vaccine or Pfizer-BioNTech's vaccine. The researchers found that while Pfizer-BioNTech's vaccine was not linked with blood issues, AstraZeneca's vaccine appears to be linked to a slight increase—about 1.13 cases per 100,000 people—in immune thrombocytopenic purpura, a condition that can cause bruising and serious bleeding (Grady, New York Times, 6/10).

• Covid-19 cases, deaths, ED visits, and hospitalizations fell substantially in 2021, particularly among older adults, who are more likely to have been vaccinated, when compared with younger people, fewer of whom are vaccinated, according to new research from CDC. Specifically, the report found that between Nov. 29 and Dec. 12, before FDA had authorized a Covid-19 vaccine, and April 18 to May 1, after a vaccine had been authorized, the ratio of cases among people 65 and older and people between ages 18 and 49 decreased 40%. Meanwhile, the ratios of ED visits, fatalities, and hospitalizations between the older and younger cohorts over the same time period decreased by 59%, 55%, and 65%, respectively. By May 1, 82% of the older cohort had been at least partially vaccinated, compared with 42% of the younger cohort. The findings demonstrate "the critical contribution on reducing Covid-19 cases, serious illness, and death especially among those over age 65," CDC Director Rochelle Walensky said of the report (Coleman, The Hill, 6/8; Edwards, NBC News, 9/8; Fernandez, Axios, 6/9).

• Moderna on Thursday applied for an EUA from FDA for its Covid-19 vaccine for use in 12- to 17-year-olds. The drugmaker reported study results last month found no cases of symptomatic Covid-19 among a group of 2,500 fully vaccinated adolescents. If authorized, Moderna's vaccine will be the second vaccine authorized for adolescents (Mandavilli, New York Times, 6/10).