Antibody responses in acute and chronic rubella

Clinical and laboratory studies with rubella vaccines in adults

Three live attenuated rubella vaccines were tested in adult volunteers. Clinical reactions were mild, but were more noticeable in vaccinated non-immune subjects than in control subjects. With the exception of two individuals, all of the remaining 54 subjects developed an immune response; the level of antibodies found was somewhat lower than that resulting from natural infection. Though virus could be isolated from some of the seronegative volunteers after vaccination, no evidence was found of transmission of infection.

Cellular viraemia in babies infected with rubella virus before birth

Chronic viraemia has been detected in 10 out of 12 rubella syndrome babies at periods ranging from 1 to 196 days. The virus was found to be associated with leucocytes, and it is assumed that removal of neutralizing antibody is the most likely explanation for the high success rate in detecting viraemia. The findings are discussed in relation to diagnosis by virus isolation, to pathogenesis, and to the possible significance in explaining the failure of the foetus to develop a tolerance to rubella virus. Several published reports of viraemia in the acute exanthematous disease are contrasted with the less frequent reports of viraemia in the chronic disease of early postnatal life.

Anticorpos neutralizantes contra rubéola num grupo de gestantes de São Paulo

Determinou-se os níveis de anticorpos neutralizantes contra rubéola em 778 soros de igual número de pacientes que freqüentam o ambulatório da Casa Maternal Leonor Mendes de Barros. Destas 778 mulheres, 600 (77,12%) apresentavam níveis de anticorpos iguais ou superiores a 4 (diluição 1:4). Em relação à idade, o grupo examinado, com uma idade média de 25,6 anos, permite verificar que no grupo etário de 15 a 19 anos a freqüência de pacientes com anticorpos na diluição 1:4 ou maior é de 79,43%; no grupo de 20 a 24 anos, 75,69%; no de 25 a 29, 77,38%; de 30 a 34, 82,50%; de 35 a 39, 75,68% e de 40 a 44, 50.00%. A comparação dos resultados obtidos em cada grupo etário da amostra examinada, mostra que os percentuais de positividade das idades compreendidas entre 15 e 39 anos são muito próximas, sendo que o grupo de 40 a 44 anos apresenta um percentual notadamente menor de pacientes com anticorpos. Esta discordância demonstrou-se estatisticamente significativa ao nível de 0,01. No que se refere à cor, das 350 gestantes de cor branca, 79,14% apresentaram anticorpos nos níveis mencionados anteriormente; das 90 pacientes de cor preta, 75,56%; das 317 mulheres grávidas de cor parda, 75,71% e das 21 gestantes de cor amarela, 71,43% possuiam níveis de anticorpos. Para inquéritos sôro-epidemiológicos de larga escala, a prova de neutralização apresenta inconvenientes de ordem prática pelo que se faz necessário estudar mais amplamente a correlação dos resultados desta técnica com aqueles fornecidos por outros, entre as quais se destaca, sem dúvida, a reação de inibição da hemaglutinação.

Vascular lesions in infants with congenital rubella

Vascular lesions were reviewed in 13 autopsied infants with congenital defects of maternal rubella. The characteristic finding was intimal fibromuscular proliferation. The internal elastic lamella and media were almost always unchanged, even in the presence of a greatly thickened intima. These arterial changes appeared to be unlike other vascular lesions described in infancy.

Severe and extensive lesions were found in four infants, and lesser changes in another five. The lesions in the pulmonary artery were probably related to clinically diagnosed peripheral pulmonary artery stenosis. Ostial stenosis of a renal artery was found in an infant with documented systemic hypertension.

The occurrence of neutralizing and complement fixing antibodies in rubella

Neutralization and complement-fixation tests to detect rubella antibody are described. Results of such tests show that between 80 and 95% of adults in England and Wales have neutralizing antibody. The presence of complement-fixing antibody indicates recent infection with rubella virus.

Results are presented showing the development of neutralizing and complement-fixing antibody after rubella.

Antibody tests on children with congenital rubella and their mothers are detailed. It is noted that higher neutralizing antibody titres are found in this group than in the general population.