There are several reasons that vaccines must be tested in equitable numbers of men and women. These include:

• Physiological differences between women and men could have implications for the protective potential of an AIDS vaccine
• Regulators are likely to require data on a vaccine’s efficacy in both men and women for licensure
• Both women and men should, for ethical reasons, have access to the benefits that accrue from participation in AIDS vaccine-related clinical research
• Men and women might have different preferences and social challenges related to vaccine use. It is important for women to participate in clinical trials to establish a vaccine’s future acceptability and potential use by women 

IAVI has engaged in a number of activities to address gender issues within clinical trial processes and advocacy efforts, and to ensure sufficient numbers of women and men in trials, including:

• Social research on the barriers women face in volunteering for clinical research, and the social impact of participation
• Training for clinical research staff and community advisory boards on gender and sexuality issues related to AIDS vaccine research, and the integration of a gender perspective in clinical research processes; development of gender training manuals for AIDS vaccine research in Africa and India
• Establishment of gender advisory boards and other mechanisms to ensure that gender perspectives continue to inform clinical research in countries in which we work
• Active engagement of women’s organizations and the recruitment of prominent women into our advocacy efforts to draw attention to the need for female-initiated and  controlled HIV prevention methods, including vaccines