Norwegian health officials on Friday confirmed the death of 13 elderly people after experiencing side effects from the vaccine from Pfizer and BioNotech. All were at least 80 years old and living in nursing homes. The information is from the Associated Press Agency.

Normal reactions to the vaccine, including fever and nausea, “can have a fatal effect on some debilitated patients,” Norwegian Medicines Agency chief physician Sigurd Hortemo said in a statement Friday.

More than 30,000 Norwegians have already received their first dose of the vaccine. However, in most cases the medical authorities are not more concerned and focus only on the more vulnerable healthy people.

“We are not concerned about this,” Steiner Madsen, the agency’s medical director, told Norwegian broadcaster NRK. “It is clear that these vaccines have very low risk, with a small exception for the most vulnerable patients,” he said.

Doctors now need to carefully consider who should be vaccinated, ”Madsen added. “People who are very weak and dying can be vaccinated after a personal evaluation,” he said.

In addition to the 13 deaths, 16 other people in Norway experienced side effects after receiving the Pfizer / Biotech vaccine, but no fatalities.