Please view the main text area of the page by skipping the main menu.

COVID-19 cluster at Japan nursing home after all residents, staff got 1st vaccine shots

Shizuoka City Hall is seen in the city of Shizuoka's Aoi Ward on Feb. 21, 2019. (Mainichi/Nobuyuki Shimada)

SHIZUOKA -- A coronavirus cluster infection has been confirmed at a nursing home in this central Japan city, after all the home's residents and staff had been given their first COVID-19 vaccinations.

    Regarding the infections, the Shizuoka Municipal Government on June 16 apologized for and withdrew comments it had made the previous day that weakened immune systems after inoculations were responsible for the coronavirus cluster at the nursing home.

    "We are sorry for offering an erroneous explanation," a city representative said at a June 16 news conference for the comments made at a press conference the day before. The city's earlier explanation had raised questions among some critics.

    According to the municipal government, on June 2, 33 residents and staff at the nursing home were given their first vaccinations. But on June 6, an employee reported feeling unwell and stayed home. Three days later, they were confirmed to have the coronavirus.

    As of June 15, in tests done over the two weeks after the vaccinations, three residents and two staff members were confirmed infected, meeting the threshold for a "cluster" infection. Some residents had reportedly not been wearing masks during daily activities.

    "Some reports say that following vaccination, the chances of infection temporarily rise, and we misunderstood the situation. We believe that leniency about prevention measures caused by a greater sense of security after vaccination was behind the increased infections," the municipal government explained at its June 16 press conference.

    In response to questions from the Mainichi Shimbun, the city's public health center said ahead of the press conference that the infections came "just a few days after vaccination, meaning it's possible that individuals were infected before they could develop antibodies."

    Following the first coronavirus vaccination, people are likely to get complacent and feel they are safe. But there is data underlining the importance of continuing prevention measures until getting the second inoculation.

    Results of investigations on how hard it is to get infected between the first and second vaccination by the Wakayama Prefectural Government released in May show that only 20% of those vaccinated one time developed the required standard values of neutralizing antibodies that would stop the virus's activities.

    The Wakayama Prefectural Government surveyed 474 individuals involved in health care services who had received their second vaccination. Among a sample of 20 people, just four had the required standard values of neutralizing antibodies up to 14 days after their first jab. However, following the second shot, all of the sample had the required antibody levels.

    Hanako Kurai, head of the Shizuoka Prefectural Government's infectious diseases countermeasures expert panel, said, "It isn't the case that infection is absolutely ruled out by vaccination. We want people to understand that to ultimately reduce their infection risk."

    (Japanese original by Kaoru Watanabe and Shota Kaneko, Shizuoka Bureau)

    Also in The Mainichi

    The Mainichi on social media