The risk is increased, but the benefit is still much higher. That's the bottom line from the U.S. Centers for Disease Control and Prevention (CDC) on covid vaccination of young people. Their vaccination commission ACIP had dealt on Wednesday with the cases of heart muscle inflammation (myocarditis) and pericarditis after the Corona vaccination with a mRNA vaccine.The conclusion was that vaccination with one of the mRNA vaccines from Biontech or Moderna apparently favors the occurrence of myocarditis, as initial data from Israel had already shown at the end of April. Individual vaccinated individuals in Germany had also reported this problem. According to the CDC data, among the just over two million 12- to 17-year-old boys vaccinated with one of the mRNA vaccines in the United States, 128 cases of myocarditis or pericarditis occurred; two cases would have been normal. Among the 4.3 million vaccinated men aged 18 to 24, there were 219 cases instead of the expected four to five. The risk was less increased for men aged 25 to 49 and for young women aged 12 to 24.

Thus, among 12- to 17-year-old male teens, one heart muscle inflammation occurred per 16,000 doses of vaccine; among 18- to 24-year-old men, one occurred per 20,000 doses; among men aged 25 to 49, one occurred per 133,000 doses; and among girls aged 12 to 17, one occurred per 115,000 doses.

The reason for the more frequent heart problems after vaccination is not yet clear

But the cases were generally mild, according to the CDC. The benefit of vaccination therefore exceeds the risk many times over, even for young people, concluded the agency, which continues to explicitly recommend vaccination starting at age 12. While one million second vaccinations cause about 56 to 69 heart muscle inflammations in teenage males ages 12 to 17, they would simultaneously prevent 215 hospitalizations, 71 ICU treatments and two deaths from Covid-19. "The benefit-risk ratio shows a positive balance for all ages and genders," the CDC said.

Nonetheless, the vaccines will come with a warning label, a U.S. Food and Drug Administration official announced during the meeting. Vaccinated individuals and their parents should be alert if the young people experience chest pain, shortness of breath, or a feeling that the heart is beating faster or irregularly, or occasionally misfires.The mechanism for the occurrence of myocarditis after mRNA vaccination is unclear. Infections can also lead to myocarditis, which is also a complication after infection with Sars-CoV-2. It is assumed that the viruses, like the vaccination, can lead to an excessive immune reaction that attacks the heart. Young people with their particularly active immune systems may therefore be more at risk.

Since most of the observed cases of myocarditis and pericarditis occurred only after the second vaccine dose, Israel is considering omitting the second injection for teenagers. Researchers led by Nadav Davidovitch of Ben-Gurion University of the Negev, in re-analyzing the registration data for the Biontech vaccine, found that 12- to 15-year-olds are already 100 percent protected against Covid-19 two weeks after the first dose. The second vaccination increases immune protection only slightly in this age group, Davidovitch told The Jerusalem Post, so in view of the increased risk of myocarditis, it may be better to forgo the second vaccination, even if the overall risk is low. This strategy, however, could be thwarted by the delta variant. At least adults are hardly protected against delta after only one vaccination.