It is often said that sex and gender differences are perceived as overlooked in research design and in clinical trials, even those on vaccines. In 2010, the World Health Organisation (WHO) published the document Sex, gender and influenza [6], which states that many reports of influenza vaccination rates as well as the safety, efficacy and effectiveness of vaccines around the world do not disaggregate data by sex.

Experts from the ASSET project performed a study to compare participation rates of males and females in clinical vaccine trials [7]. Based on available data, this comparison shows that there are no significant differences in participation rates of males and females in clinical vaccine trials, also analyzing data by trial phase. However, the fact that only a minority of the trials disaggregated data by sex and gender is a highly relevant finding, for it indicates that such a distinction was not perceived as important. It would thus be interesting to know why these data have not been reported and if the inclusion of sex-disaggregated data and gender analysis would have given different results.

All readers are invited to actively participate to the data visualization, drawing a line that show a supposed females participation rates in clinical vaccine trials according to their opinion and comparing it with the actual graphical representation of data.