Japan investigating whether 3 deaths are linked to a Moderna vaccine batch that officials fear was contaminated

• Three people in Japan died after receiving vaccines from a batch that was later recalled.
• No link has been established between the shots and deaths, per Japan's health ministry.
• Moderna recalled the shots after finding contaminants in a batch made at a similar time.

A third person in Japan died within days of receiving a Moderna vaccine from a batch that had been recalled over fears that it had been contaminated, officials in the country confirmed Monday.

A causal relationship between the deaths and the shots has not been established, and the deaths are under investigation, the country's Ministry of Health, Labour, and Welfare said in a press release.

The people - all men - died in August after being inoculated with lot 3004734 of the vaccine, which was later recalled.

It was recalled by Moderna and its Japanese distribution partner Takeda on August 28 along with two other batches. Altogether, the batches contained 1.6 million doses.

The companies have stressed that no evidence has been found that the shots caused the deaths. Deaths resulting from vaccines are rare, and deaths that occur after vaccination may be for unrelated reasons.

The companies said they did not know for sure whether lot 3004734 was contaminated but recalled it because it was made at the same time as another batch - 3004667 - that was.

An investigation led by Moderna's Spanish manufacturer ROVI Pharma Industrial Services, published Wednesday, said 3004667 was contaminated with particles of stainless steel that most likely came into the vials during the manufacturing process.

The deaths took place in August - two were confirmed August 28 without giving precise dates. Both were men in their 30s, The Japan Times reported.

The third death, confirmed Monday, was of a 49-year-old man and took place August 12, the day after he received a shot. He did not have any underlying diseases but had a buckwheat allergy, Japanese officials said.

In a joint statement Wednesday, Moderna and Takeda said the rare presence of stainless steel in the vaccine did not "pose an undue risk to patient safety." The companies said that even if the particles were injected into an arm, it would cause only a slightly stronger reaction at the injection site and no other adverse reactions.

Moderna and Takeda have not commented on the latest report outlining the third death. But in an earlier statement published August 28, Takeda said it was working with the MHLW to investigate the two deaths previously announced.

Insider tried to contact Moderna, Takeda, and ROVI Pharma Industrial Services but didn't receive a response by publication time.