Adverse reactions to COVID-19 shots were found in a massive eight-country study of 99 million vaccinated people, according to a study published Feb. 12 in the journal Vaccine. Myocarditis — inflammation of the heart muscle — and pericarditis — inflammation of the sac surrounding the heart — showed statistically significant higher adverse reactions than expected. The international research project by the Global Vaccine Data Network was established in 2021 to see if adverse reactions to COVID-19 vaccines exceeded estimates. The researchers analyzed negative reactions based on the types of va…