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Biomedical subjects

D A Tyrrell

Publications and source records attributed to D A Tyrrell.

At least 235 records · Page 13Linked to original sources

A virus from epidemic vomiting disease.

An illness consisting of vomiting, fever, and mild diarrhoea after a short incubation period was observed in a boarding school and reproduced in volunteers who received filtered extracts of faeces from a typical case. The main discriminatory diagnostic feature of the illness in volunteers was vomiting. The faeces contained no pathogenic bacteria nor any virus that could be detected in tissue cultures and there was no evidence that an infective agent could be grown in organ cultures of human intestine. The agent was shown to be ether stable and passed a 50-nm filter. Laboratory studies on another agent of uncertain significance and obtained in other epidemics are briefly described.

Adolescent↗

Antibody responses and resistance to challenge in volunteers vaccinated with live attenuated, detergent split and oil adjuvant A2-Hong Kong-68 (H 3 N 2 ) influenza vaccines. A report to the Medical Research Council Committee on Influenza and other Respiratory Virus Vaccines.

Forty-nine subjects were vaccinated with either live attenuated, detergent split, or oil adjuvant A2/Hong Kong influenza vaccines, or a saline influenza B vaccine as control. Respiratory symptoms occurred more frequently in subjects who received the live vaccine but in total there was little difference between the symptoms in the four groups. Antibody titres in nasal washings and serum were measured by haemagglutination inhibition, neuraminidase inhibition and virus neutralization tests. The oil adjuvant vaccine stimulated larger antibody responses than the other procedures. Six weeks after vaccination the volunteers were challenged with partially attenuated live A2/Hong Kong influenza virus administered intranasally. The live attenuated and oil adjuvant vaccines provided the best protection against challenge.

Adjuvants, Immunologic↗

Common colds on Tristan da Cunha.

Eight epidemics of respiratory disease have been observed among islanders of Tristan da Cunha. They seem to be initiated by the arrival of ships and transmission seemed to occur as a result of close human contact but could not always be traced. Islanders suffered from less colds than those in less isolated communities.

Adult↗

A mathematical model of common-cold epidemics on Tristan da Cunha.

Records of seven common-cold outbreaks on the island of Tristan da Cunha are compared with the corresponding time courses given by the mathematical model of Kermack & McKendrick (1927) and with an alternative model that directly involves a constant average duration of individual infection. Using computer simulation techniques the latter model is shown to be preferred and is then closely matched to the field data to obtain values for the model parameters. Consideration is then given to the intensity of epidemics predicted by the model and to the distribution of the actual epidemics relative to the theoretical epidemic threshold.

Atlantic Islands↗

Neuraminidase and resistance to vaccination with live influenza A2 Hong Kong vaccines.

Thirty-seven volunteers were inoculated intranasally with living attenuated influenza A2 viruses. Rising titres of circulating antineuraminidase (AN) were detected in 14 of 17 infected volunteers. AN was also found in nasal secretions. Statistical analysis showed that there was a correlation between the titres of haemagglutination-inhibiting antibody (HI) and AN in nasal washings, and between AN in blood and washings. Resistance to infection could be predicted from antibody titres in 29 of 37 volunteers and blood AN alone predicted the outcome of 25 volunteers.

Antibodies↗

A comparative study of attenuated influenza viruses.

Influenza A and influenza B viruses were adapted to growth at 25 degrees C. When given to volunteer subjects, the viruses were attenuated but remained infective and antigenic. The minimum immunizing dose of an egg-adapted virus appeared to be 10(5.0) EID(50). Cloning by plaque selection at 25 degrees C gave seed cultures of relatively low infectivity titres. These titres were increased when necessary by passage at 33 degrees C. No reversion to virulence was observed.Viruses attenuated in the United Kingdom and the USA were compared in volunteer trials with vaccine strains that had already been used in the USSR for mass immunization. Results were broadly similar. Currently available methods of attenuation and work with temperature-sensitive mutants are reviewed.

England↗