The update came two days after the Advisory Committee on Immunization Practices (ACIP) of the US Centers for Disease Control and Prevention (CDC) found a “likely association” between the vaccines and rare occurrences of the heart ailments among younger people, in particular following the second dose.

The FDA said it will move quickly to require the companies to add a label warning that young adults and adolescents are susceptible to this side effect first observed in Israel. Both the FDA and the CDC stressed, however, that the benefits of the vaccine clearly outweigh risks.

While some health officials said they thought the warning could lead the apprehensive to favor adenovirus-type vaccines, others pointed out that the latter type – offered in the US solely by Johnson & Johnson – has received negative press for its association with the risk of rare blood clots. J&J’s vaccine now carries a warning label. AstraZeneca’s shot is not yet been FDA-approved.

Myocarditis (inflammation of the heart) and pericarditis (inflammation of the heart’s membrane) have been seen to occur mostly after a second dose of either mRNA vaccine. According to CDC figures, 309 people in the US have been hospitalized with the symptoms. All but 14 had been released as of the beginning of this week. No deaths have been officially reported, though federal officials in Michigan are examining the death of a teenage boy shortly after vaccination .

Heart inflammation has occurred at a rate of 12.6 per million among those aged 12 to 39, according to the CDC’s Vaccine Safety Datalink. More than 138 million Americans have been fully vaccinated with the Pfizer or Moderna shots. A few vaccinated with other shots are also said to have shown symptoms.

Pfizer commented that “exceedingly small number of people” will experience this symptom after receiving the second dose of the mRNA vaccines and that patients have typically rapidly improved with conservative treatment. Moderna said it would work closely with regulatory authorities.

US officials worry about the negative effect reports of side effects could have on the sizeable number of Americans who have declined to be vaccinated. President Joe Biden said last week that his administration’s target of having 70%  of the population receive at least one dose by Jul. 4, the nation’s Independence Day, will likely not be met. Compared with 3 million people getting a shot every day in April, the nationwide rate has now fallen to 1.2 million.

Germany pulling up to UK, US in Vaccinations

Elsewhere, after lagging far behind the US and UK earlier, Germany is catching up swiftly. It has now pulled even with the UK in absolute number of vaccinations, though it has 16 million more inhabitants.

Even with its own share of resisters, Germany is now stepping up its inoculation campaign in fear of being caught in the rising tide of infections with the Delta (formerly known as Indian) variant of Covid. It now stands to benefit from the US hesitation as the expiration date for many shots earmarked for the US but not called up approaches.

Federal health minister Jens Spahn said Germany is now expecting a surge of deliveries from all vaccine makers starting in July, so that anyone who wants a shot can get it by the end of July at the latest. Moderna and BioNTech are supplying the most doses, followed by AstraZeneca and Johnson & Johnson.

Author: Dede Williams, Freelance Journalist