Japan’s ministry of health on Saturday, said in a press release that two men died within days after receiving their second doses of Moderna Inc COVID-19 vaccine shots this month.

According to the ministry, the vaccines were among the lots suspended on Thursday following the discovery of contaminants.

Japan’s domestic distributor, Takeda Pharmaceutical Co, had received reports of contaminants in some vials which prompted the country, more than a week later, to suspend the use of 1.63 million Moderna doses shipped to 863 vaccination centres nationwide.

Each of the men had a fever the day after receiving a second dose and died two days after getting the fever.

The causes of death are being investigated.

A statement on Saturday by Moderna and Takeda, read: “At this time, we do not have any evidence that these deaths are caused by the Moderna COVID-19 vaccine.”

“It is important to conduct a formal investigation to determine whether there is any connection.”

The infection control manager at St. Luke’s International Hospital in Tokyo, Fumie Sakamoto told Reuters that, “there may only be a temporal relationship between vaccination and death.”

“There are so many things we still don’t know to make any conclusions on these two cases.”

Broadcaster NHK , citing health ministry sources, reported that the contaminants found in some vials in Japan are believed to be metallic particles.

Japan had also recorded fatalities earlier, after 991 people had died after receiving shots of Pfizer Inc’s vaccine and 11 after receiving Moderna’s, but no causality between the injections and the deaths has been established, according to the health ministry.

Adverse reactions have been reported at a frequency of 0.01% for the Moderna shot.

Source: Reuters