The adjuvant access problem: barriers to broader vaccine development

Vaccine development increasingly relies on adjuvants, especially for vaccines that need extra help to produce a strong immune response. Adjuvants can improve antibody responses, reduce the amount of antigen needed, and strengthen the cellular immunity required against some difficult pathogens.

However, access to powerful adjuvants such as MF59, Matrix-M, and GSK’s AS-series remains limited. This is due not only to patents, but also to trade secrets, technical know-how, licensing and supply restrictions, and high development costs. These barriers particularly affect manufacturers in low- and middle-income countries (LMICs) and smaller vaccine developers, who often rely on aluminium-based adjuvants instead.

Some initiatives, including technology-transfer programs and non-exclusive licensing, show that wider access is possible, but usually under controlled arrangements. This commentary argues that unequal access to adjuvants is a result of current commercial, regulatory, and manufacturing systems. Improving access will require more transparent and structured approaches that protect incentives for innovation while making proven adjuvant technologies more affordable and accessible to LMIC manufacturers and smaller developers.