E. Adam

Properties of a new type 3 attenuated poliovirus. VI. Alimentary tract resistance in children fed previously with type 3 Sabin vaccine to reinfection with homologous and heterologous type 3 attenuated poliovirus.

The report is concerned with the resistance of the alimentary tract of children primarily vaccinated with the Leon 12a1b virus (Sabin) to reinfection with the homologous and a new attenuated type 3 strain, USOL-D bac. The heterologous USOL-D bac virus elicited infection in 14 out of 15 children examined (93%). The remaining child, which neither excreted virus nor responded by an increased antibody level to this virus, yielded a non-poliomyelitic virus in both pre- and postvaccination stool samples. Strain Leon 12a1b elicited infection in only 11 out of 20 children (55%). Moreover, the amount of virus in stool specimens of children re-fed with the USOL-D bac virus was larger, the period of excretion longer, and the antibody response substantially higher, than after the readministration of the Leon 12a1b virus. Control groups of non-immune children revealed no significant differences between the two strains in any of the indices observed. It is inferred from the results obtained that alimentary tract resistance of children immunized withSabins vaccine is more pronounced against homologous than against heterologous virus.

Clinical reactivity and immuno-genicity of hemagglutinin influenza vaccine. II. Clinical reactions, hemagglutination-inhibiting and strain and type-specific complement-fixing antibody responses in infants.

The reactivity and immunogenicity of a polyvalent hemagglutinin influenza vaccine was studied in subjects aged 5–7 months. The vaccine was administered in three doses either subcutaneously (0.5 ml per dose) or intradermally (0.1 ml per dose) over a period of 6–7 months. Clinical reactions, both local and febrile, even after administering two or three doses, were quite mild. After two 0.5 ml doses of vaccine administered subcutaneously, most subjects possessed hemagglutination-inhibition (HI) antibodies to all the six vaccine viruses. In most subjects the antibodies dropped to und etectable levels in the course of four to five months. A booster effect was observed after the third vaccine dose. Intradermal administration of the vaccine (0.1 ml) was much less efficient. Even three doses of vaccine did not induce antibody development in most subjects. The antibody response in the complement-fixation (CF) test using strain-specific V antigens corresponded, in general, with the results of the HI test; however the CF antibodies to the A 2/Taiwan and B/Md viruses were found much less frequently than the corresponding HI antibody. Most of the infants vaccinated subcutaneously also developed antibodies reactive in the CF test with the soluble (S) antigens of influenza A and B. They were much less frequent in subjects immunized intradermally.

The Properties of a New Type 3 Attenuated Poliovirus. IV. Comparison of the Behaviour in Humans of the USOL-D bac and Leon 12a1b (Sabin) Polioviruses.

Further evidence on the behaviour of the type 3 attenuated poliovirus USOL-D bac in human beings is reported. 1. The results of a study in which the USOL-D bac and Leon 12a1b (Sabin) viruses were administered to corresponding small groups of subjects indicate: a) both viruses multiplied well in the alimentary tract of non-immune children, the antibody responses induced by the two viruses in these subjects were quite comparable; b) in children with prevaccination antibodies resulting from previous feedings of Sabins vaccine, the USOL-D bac multiplied better and produced a more significant antibody response than refeeding with the Leon 12a1b virus; c) simultaneous administration of the mixtures of P-712, ch, 2ab (Sabins type 2 attenuated poliovirus) with USOL-D bac and with Leon 12 a1b indicated a slight dominance of type 2 over Leon and of USOL-D bac over type 2; d) the ability to grow at 40° C and the paralytogenic activity of the progenies of the USOL-D bac virus was lower than that of the corresponding progenies of Leon 12a1b. 2. The USOL-D bac virus was administered to more than 22,000 persons, including more than 9000 children not fed previously with type 3 attenuated poliovirus and more than 1700 adults. No clinical reactions were reported. The investigation of type 3 antibodies in the primovaccinees and in those previously fed with Sabins virus indicated a high immunological activity of the virus in both groups. No evidence of interference with type 2 was obtained. The results of a study in which the USOL-D bac and Leon 12a1b (Sabin) viruses were administered to corresponding small groups of subjects indicate: both viruses multiplied well in the alimentary tract of non-immune children, the antibody responses induced by the two viruses in these subjects were quite comparable; in children with prevaccination antibodies resulting from previous feedings of Sabins vaccine, the USOL-D bac multiplied better and produced a more significant antibody response than refeeding with the Leon 12a1b virus; simultaneous administration of the mixtures of P-712, ch, 2ab (Sabins type 2 attenuated poliovirus) with USOL-D bac and with Leon 12 a1b indicated a slight dominance of type 2 over Leon and of USOL-D bac over type 2; the ability to grow at 40° C and the paralytogenic activity of the progenies of the USOL-D bac virus was lower than that of the corresponding progenies of Leon 12a1b. The USOL-D bac virus was administered to more than 22,000 persons, including more than 9000 children not fed previously with type 3 attenuated poliovirus and more than 1700 adults. No clinical reactions were reported. The investigation of type 3 antibodies in the primovaccinees and in those previously fed with Sabins virus indicated a high immunological activity of the virus in both groups. No evidence of interference with type 2 was obtained.