Some countries have completely stopped immunizing adolescents or are using only one dose of vaccines against COVID-19 which is produced from RNA after reports of rare possible cardiovascular side effects. The two pharmaceutical companies that use this method are Pfizer, which is applied in Brazil, and Moderna.
Europe’s Medicines Regulatory Agency said in July it had found a possible link between a very rare inflammatory heart disease and a Covid-19 mRNA vaccine.
The possible effects present are myocarditis, which is an inflammation of the heart muscle. Pericarditis, inflammation of the membrane surrounding the heart. The researchers concluded that the risk increases with the second dose and that the chance of the problem developing is much greater in men than in women.
Check, in real time, the vaccination map of Brazil.
However, according to research by the CDC (the US Centers for Disease Control), for every 500,000 12- to 17-year-old boys vaccinated in the United States, 70 cases of myocarditis, but they would prevent 5,700 infections, 215 One hospital admission and two deaths due to COVID-19. Studies have also shown that the risk of heart disease after infection with SARS-CoV-2 and its variants is much higher than after vaccination.
The World Health Organization (WHO), as well as the CDC and the European Agency, continue to emphasize that the benefits of immunization to prevent Covid-19 are the risks.
Here is the situation in some countries that have decided to change the vaccination schedule for people aged 12-17 years:
Canada
Public Health Canada said the data indicated that reported cases of rare carditis were higher after Moderna’s Covid-19 vaccine than with Pfizer.
Denmark, Sweden
Denmark and Sweden have stopped using Moderna’s Covid-19 vaccine for younger groups, citing data from an unpublished Nordic study.
The Swedish Health Agency said it would take a break from using the vaccine for people born in 1991 and later, as data indicated an increase in myocarditis and pericarditis among vaccinated young adults.
Denmark said that despite its use of the Pfizer vaccine as a primary option for 12-17-year-olds, it had decided to stop giving the modern vaccine to under-18s on a “precautionary principle”.
Finland
Finland has stopped using Moderna’s youth vaccines and will instead give the Pfizer vaccine to men born in 1991 and later. Offers photos for ages 12 and up.
Hong Kong
A panel of health experts who advised the Hong Kong government in September recommended that children aged 12 to 17 receive only one dose of the BioNTech Covid-19 vaccine after reports of heart inflammation as a side effect.
Norway
Norway provides a dose of the Pfizer vaccine for children aged 12 to 15 years.
United kingdom
Great Britain offers all children between 12 and 15 years of age a first injection of the Pfizer vaccine. The second age-group doses won’t be offered until at least spring, when there may be more data from around the world.
Charlotte Whitmore is a contributor at Mediarunsearch.co.uk, covering a broad range of topics including news, politics, business, technology, sport, entertainment, and lifestyle. She focuses on delivering clear, balanced reporting and practical information that helps readers stay informed about current events and emerging developments. Her work highlights stories that matter to everyday audiences, with an emphasis on accuracy, relevance, and accessible journalism that keeps readers connected to the issues shaping the UK and beyond.