Moderna vaccine 100% effective in 12-18 year old youth.
Moderna announced Tuesday it had completed their clinical trial in 12–18-year-olds and the mRNA coronavirus vaccine was shown to be 100% effective in youth with no significant safety concerns. The study of 3,700 youth participants showed that none in the vaccine group got the coronavirus, compared to four cases in the placebo group.
“It is particularly exciting to see that the Moderna COVID-19 vaccine can prevent SARS-CoV-2 infection,” said Stephane Bancel, CEO of Moderna.
The company also reported an efficacy of 93% two weeks after just the first dose. Side effects were similar to ones experienced by adults and no significant safety concerns were identified.
Myocarditis/Pericarditis After Vaccination
One report that has lit up the news involves inflammation of the heart following vaccines. Symptoms are typical of heart inflammation including chest pain, shortness of breath, and electrocardiogram abnormalities. The ACIP COVID-19 Vaccine Safety Technical (VaST) Work Group session on May 17 heard several presentations on this from the Department of Defense, VAERS, and Vaccine Safety Data Link (VSD).
There initially were many reports of high numbers of individuals with myocarditis after COVID-19, but these proved to be inaccurate, and this was a very rare complication of SARS-CoV-2 infection.
VaST concluded that there are relatively few actual reports of myocarditis and they were predominately seen in adolescent and young adult males following mRNA vaccine, more often after dose two, occurring four days to two weeks after vaccination and most were mild. Within the CDC monitoring systems, however, incidence of myocarditis have not differed from expected baseline rates. This suggests this may not be a vaccine related problem but potentially from another source (virus) presently circulating in the US population.
Mixing Vaccines; does it cause worse vaccine reactions?
The UK has been mixing vaccines from early in its campaign due to shortages of everything but their own, AstraZeneca vaccine. They released data that compared the AstraZeneca and Pfizer vaccines in various prime-boost permutations in 830 patients 50 years of age and older.
This UK multi-center randomized heterologous prime-boost COVID-19 vaccination study showed that systemic reactions were greater following the boost dose in with a different vaccine compared with boosting using the same vaccine. Symptoms were similar to those well-known after receipt of the vaccines, but the frequency was twice as common when the prime dose and the boost dose were from different vaccines. The efficacy data from using different vaccines for prime and booster shots is expected in June.