By Julie Steenhuysen

CHICAGO, (Reuters) – U.S. officials hope data from Israeli military personnel will help to clarify heart muscle inflammation risk in young people who have had Pfizer/BioNTech CoVID-19 booster shots – a possible factor that regulators may consider when approving these boosters.

Rare cases of myocarditis have been associated with two-dose, high-mRNA vaccinations by BioNTech/Pfizer. Moderna (NASDAQ:) Mostly in younger men, however U.S. Health officials are working to increase awareness of the danger.

In a telephone interview, Dr. Anthony Fauci (President Joe Biden’s chief medical advisor and top U.S. expert on infectious diseases) stated that “The true question we still haven’t answered is the safety data for an mRNA among young people vis–a-vis myocarditis.”

Fauci stated that “the Israelis will fairly soon have this data because they’re vaccination everyone in the nation I think starting at 12 years of age up including their military recruits.”

In August, the U.S. Food and Drug Administration approved the Pfizer/BioNTech vaccination for adults 16 and over. However, the FDA has yet to approve its use for booster shots. The FDA instead approved Pfizer (NYSE)

FDA advices specifically pointed out that Pfizer had not provided data regarding myocarditis to younger patients in its review of the application for booster shots.

Fauci stated that Israel’s military data must help fill the safety gap on mRNA vaccinations. This was something the advisory committee wanted to know. Fauci stated that he would like to see data from Israeli military personnel specifically regarding the safety of vaccines for younger patients in relation to myocarditis.

Biden’s Administration had in mind a large campaign to boost vaccine efficacy for all Americans due to evidence of declining effectiveness.

In September, the FDA and the U.S. Centers for Disease Control and Prevention narrowed their recommendation for Pfizer/BioNTech booster for Americans aged 65 and over and those with underlying conditions and individuals in institutional and high-risk settings.

Fauci stated that he thinks the best regimen for the mRNA vaccinations would be two initial doses, separated by weeks. The booster shot will follow a couple of months later.

The FDA issued warning labels for the Pfizer/BioNTech vaccines and Moderna vaccinations in June about the possibility of developing myocarditis in young adolescents.

The FDA has granted emergency use authorization but not full approval to the Moderna vaccine as well as a one-dose Johnson & Johnson (NYSE:) shot. The FDA on Friday said it will consider Moderna’s application for booster shots at an advisory panel meeting on Oct. 14, and J&J’s booster application on Oct. 15.

The national digital database of Israel includes information from all four Israeli healthcare providers. These are the ones that administer vaccines as well as data from other institutions, including the military.

Fauci indicated that U.S. officials will follow-up with Israel’s Health Ministry on vaccination data regarding military recruits. Regularly analysing the data, the ministry has provided its conclusions on safety and effectiveness of vaccines to FDA.

A spokeswoman for the Israeli Health Ministry stated that she did not know of any study on boosters in military personnel.