Immunogenicity and reactogenicity of rhesus rotavirus vaccine given in combination with oral or inactivated poliovirus vaccines and diphtheria-tetanus-pertussis vaccine.

Immunogenicity and reactogenicity of the oral rhesus rotavirus vaccine (RRV) were assessed among 72 infants (6 weeks old) in Lahore, Pakistan, from August to December 1985. Special emphasis was placed on the possible interaction or interference caused by giving RRV at the time infants received their first polio immunization. RRV was given to the infants at the same time as diphtheria-tetanus-pertussis (DTP), oral poliovirus vaccine (OPV), or inactivated poliovirus vaccine (IPV). The immune response to RRV was assessed by plaque-reduction neutralization 3 weeks after immunization and serum immunoglobulin (Ig) G and IgA antibody levels to poliovirus type 1 were tested by enzyme-linked immunosorbent assay (ELISA) after polio immunizations. Of the infants in the group given RRV with OPV, 50% had a two- to four-fold rise in neutralization titre against rotavirus, compared with 22% in the group given RRV with DTP and 20% in the group given RRV and IPV (P less than 0.05). Interference by live oral polio vaccination in the response to RRV seems unlikely. We observed no significant difference in rates of seroconversion of IgG antibodies to poliovirus type 1 among infants aged 18 and 21 weeks who received RRV and OPV (81%), RRV with delayed OPV (67%), or RRV and IPV (59%). Administration of RRV was safe and was not associated with adverse reactions in the 6 weeks old infants. The low rate of seroconversion to rotavirus suggests that a more antigen-rich vaccine or multiple doses of the same vaccine might produce a better immune response.