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Biomedical subjects

B Portnoy

Publications and source records attributed to B Portnoy.

At least 55 records · Page 3Linked to original sources
PubMed1972

Responses of previously reinfected rubella vaccinees to challenge with Brown strain rubella virus.

The responses of seven hpv-77 rubella vaccinees to initial challenge with "wild" rubella virus have been compared with their responses to rechallenge with Brown strain rubella virus and to the responses of five "natural" immunes to initial Brown strain challenge. Previous exposure to "wild" rubella virus 220 days post vaccine-induced immunity had resulted in six of the seven vaccinees experiencing asymptomatic reinfection. On "rechallenge" none of the previously "reinfected vaccine immunes" demonstrated clinical, virologic or serologic evidence of reinfection. These data are consistent with the conclusion that persons with vaccine-induced immunity may be assured of more prolonged and solid immunity to rubella without having to suffer the clinical disease if they are reinfected with nonattenuated rubella virus. Rigidly controlled experiments, designed to study the practicality and safety of immunization with live rubella vaccine(s), followed by deliberate challenge of vaccinees with "wild" or low tissue culture passage rubella virus, seem warranted. In addition, these data indicate that it is imperative that a distinction should be made between "vaccine immunes" and previously "reinfected vaccine immunes" in any evaluation of long term rubella vaccine(s) efficacy and vaccine-induced antibody decay.

Adolescent↗
PubMed1971

Q fever in Los Angeles County. Serological survey of human and bovine populations.

Q fever is endemic and enzootic in Los Angeles County. A serological survey conducted in 1949 is compared with a current survey. Infection in dairy herds is now almost universal, while the prevalence of positive complement fixation titers in man only increased from 1.2 percent to 2.3 percent (p <0.10). The relative stability in man is accounted for by the increase in temperature requirements for milk pasteurization, the decrease in consumption of raw milk and the decrease in the number of dairy farm foci.

Adolescent↗
PubMed1971

Transmission of rubella vaccine virus from vaccinees to contacts.

The report presents evidence of the transmission of hpv-77 derived rubella vaccine virus from vaccinees to two susceptible contacts. The first instance of transmission was to a child who served as a transmission control on a "closed" study ward, and the second was to an antibody-negative mother in an "open" family study. Neither of these persons had any clinical evidence of rubella. Both had significant increases in rubella hemagglutination inhibiting (hai) antibody titers, but detectable complement fixing (cf) antibodies did not develop in either. With the kind of antigen used in our rubella cf test, this pattern of serologic response is characteristic of, but not diagnostic of, infection with the rubella vaccine virus. The serological evidence which was compatible with rubella vaccine virus infection, the complete absence of serologic or clinical evidence of "wild" rubella virus infections among the other four rubella susceptible transmission control children and the security precautions employed to ensure isolation on the "closed" ward, make "wild" rubella virus infection extremely unlikely. The evidence for rubella vaccine virus infection in the other susceptible contact is not as conclusive, because "wild" rubella virus infection is difficult to rule out in any person living in an "open" family situation. Nevertheless the need for more data is emphasized by the virtual certainty that rubella vaccine virus transmission did occur in the subject on the isolation ward, plus the high probability that the infection observed in the family group setting also represented transmission of rubella vaccine virus. Such data can only come from close surveillance of recipients of live rubella virus vaccines and their contacts in the future.

Adult↗