Rotavirus is surging across the United States, with wastewater surveillance identifying the San Francisco Bay Area as a particular hotspot, according to data from the U.S. Centers for Disease Control and Prevention and the 40-state-tracking WastewaterSCAN Dashboard. High levels of the virus have also been detected in New Jersey, Connecticut, and along the Northeast coast, with a nationwide rise evident since mid-December.
This uptick stands in stark contrast to the situation in the United Kingdom, where robust national surveillance reports rotavirus activity currently below expected levels for the time of year. The disparity throws a spotlight on a recent and controversial shift in American public health policy that experts warn could undermine decades of progress.
A Highly Contagious Threat to the Young
Rotavirus is a highly contagious virus causing gastroenteritis, with symptoms including severe watery diarrhoea, vomiting, fever, and stomach cramps that can last between three to eight days. While often mild in adults, it poses a severe risk to infants and young children under five, primarily through dehydration. The virus spreads through the faecal-oral route, via contaminated hands, surfaces, and can also be transmitted through the air via coughing and sneezing.
Before the introduction of a vaccine, rotavirus was the leading cause of severe diarrhoea in infants and young children. In the U.S., it caused an estimated 55,000 to 70,000 hospitalisations and 20 to 60 deaths annually. In England and Wales, it led to approximately 12,700 hospitalisations and 130,000 GP visits each year.
Major Shift in U.S. Vaccine Recommendations
The most significant development, however, is not the current case numbers but a fundamental change in the official U.S. approach to vaccination. In January 2026, the U.S. Department of Health and Human Services (HHS), under Secretary Robert F. Kennedy Jr., announced a major overhaul of the childhood immunisation schedule.
The rotavirus vaccine, previously a routine recommendation for all infants, was moved to a category of “shared clinical decision-making.” This means the HHS now states that parents should decide with their doctors whether the vaccine is right for their children, breaking from previous CDC guidance that all children receive it.
Secretary Kennedy stated the agency was “aligning the U.S. childhood vaccine schedule with international consensus while strengthening transparency and informed consent,” citing Denmark—which does not routinely vaccinate against rotavirus—as a model. This change was part of a broader reduction in routinely recommended childhood vaccines.
Medical Backlash and Legal Challenges
The policy shift has been met with fierce criticism from major medical bodies. Dr. Sean O’Leary, chair of the American Academy of Pediatrics Committee on Infectious Diseases, warned, “They’re going to bring back suffering and death. I don’t say that with any hyperbole, that’s exactly what’s going to happen.”
Experts have criticised the process, noting it occurred without the customary public deliberation and input from paediatricians and immunologists. Dr. Charles Whittaker of UC Berkeley School of Public Health described it as happening “in the dark.” The move has also prompted legal action, with fifteen states reportedly suing HHS over the changes.
Critics argue that moving vaccines to a “shared decision-making” model creates barriers to access and could lower vaccination rates. Dr. Yvonne Maldonado, a professor of paediatrics at Stanford University, noted people often underestimate diarrhoeal disease, but stressed “rotavirus can actually be very severe in infants and young children.”
Vaccine Effectiveness and Safety
The rotavirus vaccine’s track record is well-established. In the UK, where the Rotarix® vaccine is given orally at 8 and 12 weeks as part of the NHS schedule, reported cases fell by over 70% within three years of its 2013 introduction. The vaccine prevents infection in about 8 out of 10 babies who receive it, with clinical trials showing 90-100% effectiveness against severe disease.
In the U.S., the CDC states that between 94% and 96% of vaccinated children are protected from hospitalisation, with pooled effectiveness against hospitalisations and emergency visits around 83-84%. Nationally, the vaccines have averted an estimated 45,000 hospitalisations and 342,000 clinic and emergency department visits.
The vaccine is considered very safe. Like any medicine, it can have side effects, but the CDC states these are “usually mild and go away on their own.” There is a very small associated risk of intussusception, a rare bowel blockage, affecting an estimated 1 in every 20,000 to 100,000 U.S. infants. This risk is significantly lower than the 1,900 annual cases of intussusception that occurred in infants before the vaccine’s introduction.