Some countries have halted altogether or are giving only one dose of COVID shots based on so-called mRNA technology to teens following reports of possible rare cardiovascular side effects.

Europe’s drug regulator said in July it had found a possible link between a very rare inflammatory heart condition and COVID-19 vaccines from Pfizer/BioNTech and Moderna (MRNA.O). read more

However, the benefits of mRNA shots in preventing COVID-19 continue to outweigh the risks, European and U.S. regulators and the World Health Organization have said.

Here are some of the steps some countries are taking:

CANADA

The Public Health Agency of Canada said data suggested that reported cases of rare heart inflammation were higher after Moderna’s COVID-19 vaccine compared with the Pfizer/BioNTech shots. read more

DENMARK

The Danish Health Agency said on Friday that it was continuing to offer Moderna’s COVID-19 vaccine to under-18s, and that a statement on Wednesday suggesting a suspension had in fact been a miscommunication. read more