24-04-2025
Fact Check: Japanese study does not report explosion in deaths among COVID-vaccinated
A new study concludes excess deaths increased in Japan during the COVID-19 pandemic but does not report any explosion in mortality among those vaccinated against the disease, as claimed in social media posts.
The research, published, opens new tab on April 5 in BMJ Public Health, looked at excess deaths - the number of deaths over and above past patterns - in Japan between 2020 and 2023 compared with 2015 to 2019.
The study found that Japan's excess death rate dipped in 2020, then began climbing, as in other countries, then started tapering off in 2023. The researchers also identified local factors - including how rural an area is or recent flu trends - that might account for variations in excess death rates at the provincial level.
Social media posts, opens new tab on April 13 shared a headline from Slay News, a website that Reuters has fact-checked on multiple occasions, about the study that said Japan had issued a global alert about an explosion in excess deaths among vaccinated people.
'This is absolutely a false and misleading claim,' Ganan Devanathan, a doctoral student from the University of Tokyo and lead author of the study, told Reuters in an email. 'Our research in no way suggested that excess deaths are exploding amongst the COVID-vaccinated population. We did not investigate any association with vaccines, or the vaccinated population.'
The study concludes that, despite Japan's success in keeping excess deaths down at the start of the pandemic, they increased as it went on, peaking in 2022.
'While numerous events occurred in Japan during the pandemic, it is difficult to draw associations on their impact on excess mortality, and it is likely highly multifactorial,' the authors wrote. 'Urban and rural prefectures may exhibit different patterns as identified, and the interaction with other infectious diseases, such as influenza, likely plays a role.'
The study also says that, while more research is required, the low levels of excess deaths in Niigata prefecture in 2022 and 2023 could be down to high COVID vaccination rates there.
Japan began rolling out COVID vaccines on February 17, 2021.
Overall, Japan had an estimated 219,516 excess deaths between 2020 and 2023, according to, opens new tab the study. Compared with the pre-pandemic period, the researchers found there were 22,045 fewer deaths than expected in 2020. Then, in 2021, there were an estimated 31,791 excess deaths, 119,060 the following year and 90,710 in 2023.
Reuters has previously addressed misleading posts and articles saying that excess deaths during the pandemic were caused by COVID vaccines rather than by COVID itself.
Addressing a similar claim, Paul Hunter, a professor of medicine from the University of East Anglia, said in a 2024 online article, opens new tab that spikes in mortality during the pandemic period tracked with COVID waves. He also pointed out that, while larger numbers of people who died in 2022 and 2023 were vaccinated, that is because the majority of people were vaccinated by that time, but the rate of deaths among vaccinated people was lower than among the unvaccinated.
In addition, Hunter said, possible explanations for excess deaths not linked to COVID 'include the long-term impact of COVID infections, the return of infections such as flu that had been suppressed during the pandemic ... and delays in diagnosing life-threatening conditions as health services struggled to cope with the pandemic and its aftermath.'
VERDICT
False. The study concludes excess deaths increased in Japan during the COVID-19 pandemic, not that vaccines caused the increase in mortality.
