TOKYO -- Women in at least 12 municipalities were given more than the usual three shots of HPV vaccine given to protect against cervical cancer, Mainichi Shimbun research has revealed.

One reason for this was apparently that the women's vaccination records kept by each municipality showed they hadn't received HPV shots. Osaka University's Yutaka Ueda, who is currently researching HPV vaccines, mentioned that while the risk of health effects from excess shots is extremely low, this was still an "undesirable" situation, and called for measures to prevent a recurrence. The error has also brought to light issues regarding recordkeeping.

Regarding HPV vaccinations in Japan, some women born between fiscal years 1997 and 2007, now in their late teens to late 20s, skipped getting vaccinated due to concerns about side effects. The national government is currently undertaking a "catch-up" campaign to deliver shots to these women for free. The individuals are sent notifications from their municipal government, after which they visit a health provider for the vaccination. It was within this framework that the excess shots were provided.

Between July and September, the Mainichi Shimbun asked whether excess vaccinations had occurred during catch-up campaigns at a total of 74 municipalities across the country -- Tokyo's 23 special wards and all the prefectural capitals and government-designated major cities. The answer was affirmative from 12 of these: the cities of Aomori, Sendai, Mito, Nagoya, Kyoto, Kobe, Fukuoka, Nagasaki and Kumamoto, as well as Tokyo's Chiyoda, Koto and Arakawa wards.

Asked why the issue occurred, some municipal governments responded that "the details are unknown" or declined to answer "due to privacy issues," but there were largely three reasons given:

The first was that the local governments lacked records of the women's inoculation history. Most of the local governments covered in the research had checked preliminary medical examination forms filled out by the individuals and electronic immunization records of residents to prevent giving excess shots. Notifications for the catch-up shots was then sent out, excluding women who had already received their complete regimen.

However, those records are kept by the governments of municipalities where the women lived at the time of the vaccinations. After some women moved, the governments for their new places of residence had no records, leading to them being treated as though they were unvaccinated. This happens because local governments keep records separately and there is no unified system to share the information, and led to the excess shots being given in the cities of Aomori, Mito, Nagoya and Kumamoto.

The second reason was that records were erased after a certain length of time. The municipalities, not the national government, are tasked with maintaining the records. Under regulations set in the Immunization Act, records must be kept for a minimum of five years, and it is left up to each municipality whether and how much longer to hold the records for. Sendai had retained only the records since fiscal 2017, Kobe since fiscal 2015 and Nagasaki had kept records for only the previous five years.

The third reason was people misremembering their vaccination history. Even after receiving the notifications, excess shots would not occur if the women recalled having already gotten all of theirs. In 12 cities or wards, however, except in cases where the details are unknown, most of the women given excess shots were not aware of having been inoculated.

The local governments are asking those invited to receive catch-up shots to bring their mother and child health handbooks which contain their vaccination records to the medical institutions. In many of these cases of excess vaccination, the women noticed that they had already been vaccinated when checking their handbooks after their catch-up shots.

(Japanese original by Koji Endo, Tokyo City News Department)