Danish Researchers Study Non-Specific Vaccine Effects in Guinea-Bissau

They reported that live vaccines such as measles and tuberculosis shots appeared to reduce overall child mortality beyond protection against those specific diseases. They also reported that inactivated vaccines such as the diphtheria-tetanus-pertussis shot were associated with higher mortality in some groups.

The researchers published these observations in multiple papers over many years. The World Health Organization reviewed the findings but did not change its vaccine recommendations. Other scientists noted that the results were difficult to replicate and that the methods differed from standard approaches.

Health and Human Services awarded the Bandim group $1.6 million to study whether the birth dose of hepatitis B vaccine affects immune systems or causes neurological issues. The study plans to withhold the vaccine from half of 14,000 newborns in Guinea-Bissau.

The World Health Organization and some infectious disease specialists have stated that withholding the dose is unethical given high hepatitis B prevalence in the country. Kennedy Jr. cited one of the researchers' papers when announcing a $2.6 billion cut in U.S. support for Gavi.

The agency estimated the reduction could lead to 1.2 million preventable deaths over five years. A separate $600 million in current Gavi funding was also frozen.

Danish statisticians and infectious disease experts have published articles in the past 18 months questioning the methods used by Aaby and Benn. A national scientific board is investigating the work. Lone Stensballe, who previously collaborated with the pair for 20 years, said their studies show a pattern of confirmation bias.

Anders Hviid, chief epidemiologist at Statens Serum Institut, said Benn does not influence Danish vaccine policy. Danish authorities continue to follow their existing vaccine schedule, which includes inactivated vaccines. The researchers did not respond to requests for comment on the current developments.