TOKYO (Reuters) – About 70% of coronavirus patients tested at a Tokyo hospital last month carried a mutation known to reduce protection from the vaccine, Japanese public broadcaster NHK said on Sunday.
The E484K mutation, nicknamed “Eek” by some scientists, was found in 10 of the 14 people who tested positive for the virus at the Medical University of Tokyo University of Medicine and Dentistry in March, the report said.
During the two months to March, 12 of the 36 COVID patients carried the mutation, none of them having recently traveled abroad or reported contact with people who have already done so, the agency said.
Hospital officials were not immediately available for comment.
Before the summer Olympics scheduled to start in July, Japan is battling a new wave of infections. Health experts are particularly concerned about the spread of mutant strains, even though large-scale vaccinations in the general population have not yet begun.
On Friday, 446 new infections were reported in Tokyo, although this is still well below the peak of more than 2,500 in January.
In Osaka, a record 666 cases have been reported. Health experts have expressed concern about the spread across the western metropolis of a mutant strain known to have arisen in Britain.
NHK said that none of the patients at the Tokyo hospital carried the British strain.
Reporting by Ritsuko Ando; William Mallard edition