Sweden is now the latest country to hit pause on the AstraZeneca vaccine pending an investigation into reports of blood clots in some recipients.
Germany, France, Italy and Spain are among the other countries to also stop administering doses.
But the World Health Organization and other regulators still insist the shot is safe.
Chief Scientist Dr. Soumya Swaminathan of World Health organization said: "So far, of the 300 million doses that have been given to people across the world, of course, using different vaccines, there is no documented death that's been linked to a COVID vaccine."
Executive Director Emer Cooke of the European Medicines Agency said: "Currently we are still firmly convinced that the benefits of the AstraZeneca vaccine in preventing COVID-19 with its associated risk of hospitalization and death, outweigh the risk of those side affects."