Inmunogenicidad, inocuidad y eficacia de una vacuna tetravalente obtenida por recombinación genética de rotavirus aislados de monos rhesus y seres humanos en Belém, Brasil

• A. C. Linhares ^[1] ; Y. B. Gabbay ^[1] ; J. D. P. Mascarenhas ^[1] ; R. B. de Freitas ^[1] ; C. S. Oliveira ^[1] ; N. Bellesi ^[2] ; T. A. F. Monteiro ^[1] ; Zéa Lins-Lainson ^[1] ; F. L. P. Ramos ^[1] ; S. A. Valent ^[1]
  1. [1] Instituto Evandro Chagas, Belém, Pará, Brasil
  2. [2] Clínica de Medicina Preventiva de Pará, Belém, Pará, Brasil.
• Localización: Revista Panamericana de Salud Pública = Pan American Journal of Public Health, ISSN-e 1680-5348, ISSN 1020-4989, Vol. 3, Nº. 5 (Mayo), 1998, págs. 326-336
• Idioma: español
• Títulos paralelos:
  • Immunogenicity, safety and efficacy of tetravalent rhesushuman, reassortant rotavirus vaccine in Belém, Brazil
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• Resumen

  • A tetravalent rhesus-human reassortant rotavirus (RRV-TV) vaccine (4 104 plaqueforming units/dose) was evaluated for safety, immunogenicity and efficacy in a prospective, randomized, double-blind, placebo-controlled trial involving 540 Brazilian infants. Doses of vaccine or placebo were given at ages, 1, 3 and 5 months. No significant differences were noted in the occurrence of diarrhoea or vomiting in vaccine and placebo recipients following each dose. Low-grade fever occurred on days 3–5 in 2–3% of vaccinees after the first dose, but not after the second or third doses of vaccine. An IgA antibody response to rhesus rotavirus (RRV) occurred in 58% of vaccinees and 33% of placebo recipients. Neutralizing antibody responses to individual serotypes did not exceed 20% when measured by fluorescent focus reduction, but exceeded 40% when assayed by plaque reduction neutralization.

    There were 91 cases of rotavirus diarrhoea among the 3-dose (vaccine or placebo) recipients during two years of follow-up, 36 of them among children given the vaccine. Overall vaccine efficacy was 8% (P = 0.005) against any diarrhoea and 35% (P = 0.03) against any rotavirus diarrhoea. Protection during the first year of followup, when G serotype 1 rotavirus predominated, was 57% (P = 0.008), but fell to 12% in the second year. Similar results were obtained when analysis was restricted to episodes in which rotavirus was the only identified pathogen. There was a tendency for enhanced protection by vaccine against illness associated with an average of 6 or more stools per day. These results are sufficiently encouraging to warrant further studies of this vaccine in developing countries using a higher dosage in an attempt to improve its immunogenicity and efficacy.