Abstract: The invention relates to a mucosal surface antigen which is used to promote and increase in the immune response against co-administered antigens in the formulations out line in the invention. Said novel formulations are obtained from the dual use of the surface antigen as an immunostimulatory agent and, at the same time, as a vaccine antigen. In this way it is possible to obtain multiple formulations of the hepatitis B surface antigen and heterologous antigens, with immunogenicity levels similar to those obtained following parenteral administration and with a reduction in components that can dispense with the use of nasal adjuvants, thereby converting same antigens into elements that can promote an increase in the response to the other co-administered antigens. Said novel use of the hepatitis B virus surface antigen and the resulting antigen formulations can be used in the pharmaceutical industry as therapeutic and preventive vaccine formulations.