Antigen content of inactivated poliovirus vaccine for use in a one- or two-dose regimen.

The immunologic response to inactivated poliovirus vaccine following one and two doses has been studied in infants in developing and developed countries using vaccine prepared at the Rijks Instituut voor de Volksgezondheit, The Netherlands. Virus was grown in microcarrier cultures of monkey kidney cells, purified, concentrated, and inactivated with formalin. The vaccines used contained different quantities of D-antigen units for each of the three types. The data reveal that both antibody and immunologic memory (booster-type responsiveness) were induced in virtually all individuals following a single dose of a sufficient quantity of antigen. Immunologic memory was readily revealed by the booster-type response following a second dose given six months after the first. The degree of booster-type response to a second dose is linked primarily to the quantity of antigen used for primary immunization, and secondarily to the quantity of antigen used for the booster dose. The data base is presented for formulating the antigen content of an inactivated poliovirus vaccine that can be relied upon to be protective after the first dose when given alone or when incorporated with combinations of other antigens (diphtheria-per tussis-tetanus) that may require two or more doses.