Two nationally recognized scientists with decades of experience advising U.S. vaccine policy argue that it is a mistake to exclude well-designed observational studies in determining how well vaccines work on a year-to-year basis.
In a perspective published in The New England Journal of Medicine, Arnold Monto and Helen Chu say relying only on randomized clinical trials isn't feasible or practical when it comes to respiratory infection vaccines that are updated annually.
Monto and Chu have been advisers to the federal government on vaccine policy. The recommended clinical trial approach, they say, overlooks other important scientific evidence, including observational studies that often reveal more useful information on how well vaccines are working in near real time.
"A randomized clinical trial does not give us the full picture of how the vaccine is working to prevent illnesses and death year to year," said Monto, professor emeritus of epidemiology and global public health at the University of Michigan School of Public Health.
"We are not arguing that randomized clinical trials are not the gold standard. However, observational studies, such as those used for influenza vaccines, are necessary to evaluate respiratory viruses and their changing variants."
Monto is also co-director of the Michigan Center for Respiratory Virus Research & Response and has served as an adviser to federal agencies on vaccines and the World Health Organization.
Chu is a professor of medicine and allergy and infectious diseases at the University of Washington and runs one of the country's most comprehensive respiratory virus surveillance programs.
