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New COVID vaccine trial does not analyze sex data

‘This is worrisome because men and women respond to viruses and vaccines differently’

A shortcoming in the peer-reviewed data from the Moderna COVID-19 vaccine trial, published Monday in the New England Journal of Medicine, was it did not analyze the data by sex, said Nicole Woitowich, an expert on women in biomedical research.

“This is worrisome because we know men and women respond to viruses and vaccines differently,” said Woitowich, associate director of the Women’s Health Research Institute at Northwestern University Feinberg School of Medicine.  

“Women are able to mount a greater immune response to vaccines and are generally less susceptible to viral illness compared to men,” she said. “Early reports have shown that COVID-19 is no different, and men have more severe disease and greater mortality rates compared to women. But sex was never mentioned outside of describing who the study participants were.”

This study, which was funded in part by the National Institutes of Health, also demonstrates a failing of their guidelines which requires studies to “consider sex as a biological variable,” Woitowich said. In 2016, the National Institutes of Health implemented a policy requiring NIH-funded research to consider sex as a biological variable.

“It’s disappointing to see that while NIH has developed policies to improve our understanding of how sex influences health and disease, it is not being implemented into research practice,” Woitowich said. “While women being left out is nothing new – this time it has critical public health implications.” 

Historically, women have remained underrepresented in biomedical research, which has led to gaps in the understanding of women’s health. A recent study at Northwestern found while scientists are now including more females as research subjects compared to 10 years ago, they still fail to analyze data by sex. 

“This practice has always harmed women, yet we are now being confronted with it on a larger, global scale,” Woitowich said. “We have to do better going forward.”