Scientific Reports this morning retracted a controversial paper claiming to show that mice given a human papillomavirus (HPV) vaccine showed signs of neurological damage. The paper was assailed by critics as being "pseudoscience" that could have "devastating" health consequences by undermining public confidence in a vaccine given to girls to prevent cervical cancer.

"I'm pleased that finally they did manage to retract it, but it was a very long process," says Alex Vorsters, a molecular biologist at University of Antwerp in Belgium. However, the controversy seems likely to continue. "The Authors do not agree with the retraction," the retraction notice states.

The paper, by a group led by Toshihiro Nakajima of Tokyo Medical University in Japan, was published online 11 November 2016. It describes impaired mobility and brain damage in mice given an enormous dose of HPV vaccine along with a toxin that makes the blood-brain barrier leaky. Shortly after the paper appeared, two groups separately wrote to Scientific Reports and its publisher, the Nature Publishing Group (NPG), pointing out problems with the experimental setup, the use of a dose proportionally far larger than what is normally given, the use of the toxin, and inconsistencies between the data presented and the descriptions of results, among other issues.

At the time, Nakajima defended the paper in an email to Science , claiming the experimental strategy was similar to those commonly used in other mouse studies. He also wrote that the group was preparing a detailed response to the criticisms.

But the retraction notice posted this morning sides with the critics: "The Publisher is retracting this Article because the experimental approach does not support the objectives of the study." It goes on to explain, "The co-administration of pertussis toxin with high-levels of HPV vaccine is not an appropriate approach to determine neurological damage from HPV vaccine alone."

Nakajima did not immediately respond to emails seeking comment.

The paper alarmed public health advocates in Japan and worldwide because it seemed to provide some scientific basis for what had been anecdotal reports of alleged HPV vaccine side effects, including headaches, fatigue, and poor concentration. Media reports of young women supposedly suffering such adverse reactions and pressure from antivaccination campaigners had led Japan’s Ministry of Health, Labour, and Welfare to stop recommending the vaccine in June 2013. Vaccination rates in Sapporo, which started providing the vaccine for free in 2011, plummeted from around 70% of eligible girls to near zero, according to Sharon Hanley, a cancer epidemiologist at Hokkaido University in Sapporo. Japan as whole has relatively low HPV vaccination rates, and Hanley believes that means the country is unlikely to see any reduction in its current 9000-plus cases of cervical cancer and 3000 related deaths each year.

Hanley and Vorsters are both critical of Scientific Reports for taking so long to investigate the paper; the delay effectively allowed bad science to be in circulation for 17 months, they argue. The paper has been cited 20 times and mentioned in nearly a thousand tweets, according to Scientific Reports metrics.

Responding to an email from Science seeking comment on the length of the investigation, a spokesperson for Scientific Reports wrote, "For confidentiality reasons, we cannot discuss the specific history of a Scientific Reports paper with anyone other than the authors."

"Sadly, I don’t think this retraction will affect public opinion in general because I suspect most Japanese citizens are not aware of the publication," Hanley says. But she hopes that it might help lead government officials to resume recommending the vaccine.

Vorsters, a member of the HPV Prevention and Control Board based at the University of Antwerp, believes those promoting public health may have to rethink their approach to encouraging vaccination. Given how the antivaccination lobby works, he says, the bogus paper "will probably reappear in another journal." And even if it doesn't, "there are a lot of other papers online [reporting] bad science," he says. Instead of trying to retract them all, "maybe we should focus on the positive effects of vaccination," he adds.