USA – CDC : mRNA COVID-19 vaccines – benefits outweigh the risks
The benefits of messenger RNA Covid-19 vaccines clearly outweigh the risks despite heart complications seen in a relatively small number of mostly young men, according to the US Centers for Disease Control and Prevention.
Roughly 1,200 cases of myocarditis, or inflammation of the heart wall, were reported in people who received mRNA vaccines, the CDC said in its Morbidity and Mortality Weekly Report on Tuesday. But with about 296 million doses of mRNA vaccines having been administered as of June 11, the benefit is clear in all populations, including adolescents and young adults, the researchers reported.
Myocarditis is the inflammation of the heart muscle which can be accompanied by inflammation of the thin tissue surrounding the heart, known as pericarditis. When the two combined events take place, it is referred to as myopericarditis.
People who receive mRNA COVID-19 vaccines are up to 91 percent less likely to develop the disease than those who are unvaccinated, according to a new nationwide study of eight sites, including Salt Lake City. For those few vaccinated people who do still get an infection, or “breakthrough” cases, the study suggests that vaccines reduce the severity of COVID-19 symptoms and shorten its duration.
The study found that mRNA COVID-19 vaccines were:
- 91% effective in reducing risk for infection once participants were “fully” vaccinated, two weeks after the second dose.
- 81% effective in reducing risk for infection after “partial” vaccination, two weeks after the first dose but before the second dose was given.
- Presence of fever was reduced 58% percent among those vaccinated with a breakthrough infection.
These findings also suggest that fully or partially vaccinated individuals who get COVID-19 might be less likely to spread the virus to others. The researchers found that infected study participants who had been fully or partially vaccinated when infected had 40% less detectable virus in the nose and did so for six fewer days compared to those who were unvaccinated.