Japan suspends 1.63 million Moderna COVID-19 vaccine doses over contamination fears

Vial of Moderna COVID-19 vaccine
A vial of Moderna COVID-19 vaccine in Tokyo.
(Eugene Hoshiko / Associated Press)

Japan suspended use of about 1.63 million doses of Moderna’s COVID-19 vaccine Thursday after contamination was found in unused vials, raising concerns of a supply shortage as the country tries to accelerate inoculations amid a coronavirus surge.

The health ministry said contamination was reported from multiple vaccination sites. Some doses might have been administered, but no adverse health effects have been reported so far, officials said.

Takeda Pharmaceutical, a Japanese drugmaker in charge of sales and distribution of the Moderna vaccine in Japan, said it decided to suspend use of doses manufactured in the same production line as a safety precaution.


It asked Moderna to conduct an emergency investigation and told medical institutions and organizers to stop using the vaccine produced in Spain. The company shared the production numbers that may be affected.

The Japanese health ministry and Takeda did not give details on the type of contamination or whether the doses in question may have been distributed outside Japan.

The problems arose just as Japan is struggling with surging coronavirus infections, with daily new cases hitting new highs in many parts of the country and severely straining its healthcare system.

A new CDC study finds more than 71% of COVID-19 infections in Los Angeles County between May 1 and July 25 were among the unvaccinated.

Aug. 25, 2021

Chief Cabinet Secretary Katsunobu Kato told reporters that the government and Takeda are discussing ways to minimize the impact on Japan’s vaccination progress.

“We will do [our] utmost in order to avoid any impact on vaccination progress, especially at work sites and large-scale centers,” Kato said.

Japan relies entirely on foreign-developed vaccines by Moderna, as well as Pfizer and AstraZeneca. Moderna’s vaccine has been used since mid-June at large-scale vaccination centers and workplaces, and has helped speed up Japan’s rollout.


About 43% of the Japanese population have been fully vaccinated, with about 1 million doses being administered daily.