Dr. Sigurd Hortemo, chief physician at the Norwegian Medicines Agency, said in a statement that common side effects like fever and nausea shortly after vaccination may have led to more serious outcomes and deaths among elderly, frail patients.
According to the Norwegian Medicines Agency, as of Thursday, reports of 23 suspected deaths were sent to the Norwegian ADR health registry, including 13 reports assessed by health officials. The patients died within a week of vaccination, a spokesperson said.
"We cannot rule out that adverse reactions to the vaccine occurring within the first days following vaccination (such as fever and nausea) may contribute to more serious course and fatal outcome in patients with severe underlying disease," the agency said in the statement.
The statement noted that Pfizer’s large clinical trials didn’t test the vaccine on patients with severe illness or those older than 85.
Indeed, prior to emergency approval from the U.S. Food and Drug Administration, a committee advising the agency endorsed the product and found no specific safety concerns among subgroup analyses but did list several unknowns that will need to be investigated further, including duration of immunity, efficacy in certain high-risk populations, those previously infected, as well as effectiveness among asymptomatic infection, long-term effects of COVID-19 disease, mortality and transmission of SARS-CoV-2. The trial tested patients up to 85 years old.
According to Pfizer, the Norway agency isn't alarmed by the small number of incidents.
"Our immediate thoughts are with the bereaved families," Pfizer wrote to Fox News in an emailed statement. "Pfizer and BioNTech are aware of reported deaths following administration of BNT162b2. We are working with the Norwegian Medicines Agency (NOMA) to gather all the relevant information. The Norwegian Authorities have prioritized the immunization of residents in nursing homes, most of whom are very elderly with underlying medical conditions and some who are terminally ill."
"NOMA confirmed the number of incidents so far is not alarming, and in line with expectations," the statement continues. "All reported deaths will be thoroughly evaluated by NOMA to determine if there is any relation to the vaccine. The Norwegian government will also consider adjusting their vaccination instructions to take the patients’ health into consideration."
Nevertheless, the medical director of the Norwegian drug agency advised against frail patients receiving the vaccine.
"If you are very frail, you should probably not be vaccinated," Steinar Madsen at the Norwegian Medicines Agency told reporters Thursday, per Norway Today.
COVID-19 vaccines typically require several weeks before the body builds enough immunity to protect against the disease.
Pfizer’s shot has been reported to create non-serious adverse reactions such as pain at the injection site, fatigue, headache, muscle pain, chills, joint pain, fever, injection site swelling, injection site redness, nausea, malaise and lymphadenopathy, though experts say these symptoms typically self-resolve several days after vaccination.
Fox News has requested further comment from the Norwegian Medicines Agency.
Fox News’ Alexandria Hein contributed to this report.