Two men in Japan died this month days after receiving potentially contaminated doses of the Moderna vaccine, though officials said Saturday that it is too early to draw a definitive conclusion on any connection.
Japan’s health ministry announced Saturday that the two people, both in their 30s, died days after receiving their second doses of the Moderna vaccine, according to Reuters.
Health officials said that each of the men reported having a fever the day after receiving the second dose, with both dying two days after coming down with a fever.
While health officials told reporters that there was no evidence suggesting that the shots the men received were contaminated, the doses were among the lots suspended by Japan Thursday due to reports of contaminants in the vials.
The suspension included a total of roughly 1.63 million doses of the Moderna vaccine.
Both Moderna and Japan officials said at the time that the decision was precautionary, noting that there had been no issues associated with the doses at that point.
Moderna and Takeda Pharmaceutical Co., which distributes the shot in Japan, said in a press release Saturday that the deaths of the two men was “a tragic event,” adding, “the loss of life is something that we take very seriously.”
However, the companies noted that they did “not have any evidence that these deaths are caused by the Moderna COVID-19 vaccine, and it is important to conduct a formal investigation to determine whether there is any connection.”
Moderna and Takeda said they were working with Japan’s Ministry of Health, Labour and Welfare to investigate the fatalities, adding that the probe “is being conducted with the greatest sense of urgency, transparency and integrity and is of the highest priority.”
“Takeda and Moderna will keep the public informed as we learn more,” they added.
Japan’s health ministry said Thursday that the doses, which reportedly had unknown foreign substances in the vials, had already been sent to more than 800 vaccination sites across the country.
The department asked that health care centers and other vaccine distribution sites that received the potentially contaminated lots refrain from using them.
As of Saturday, roughly 44 percent of Japan’s population had been fully vaccinated against COVID-19, with a total of more than 124 million shots administered, according to Reuters.
While Japan’s health ministry previously reported that nearly 1,000 people in the country had died after receiving the Pfizer-BioNTech shot, and 11 following the Moderna inoculation, there has been no evidence to indicate that the injections contributed to the fatalities.