Factors affecting antibody response of newborns to repeated administration of rotavirus RIT 4237

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A comparative trial of rhesus monkey (RRV-1) and bovine (RIT 4237) oral rotavirus vaccines in young children

Heterologous live, oral rotavirus vaccines of rhesus monkey (RRV-1) and bovine (RIT 4237) origin were tested for immunogenicity, excretion of virus, and clinical reactions in six- to eight-month-old infants. Antibody response, indicating infection with the vaccine virus, was detected in 21 (88%) of 24 children receiving the RRV-1 vaccine and in 18 (75%) of 24 receiving the RIT 4237 vaccine. Excretion of virus in the stools within one week after vaccination was demonstrable in 84% of the RRV-1 and in 21% of the RIT 4237 vaccinees. RRV-1 vaccination was associated with a febrile response (over 38 C) that clustered on days 3 or 4 postvaccination in 64% of the recipient children. In addition, 20% of the RRV-1 vaccinees had watery stools on days 4 or 5. Fever on days 3 and 4 and loose stools were not seen in the RIT 4237 vaccinees. We concluded that in young children the RRV-1 (rhesus monkey) rotavirus vaccine is more immunogenic than the RIT 4237 (bovine) rotavirus vaccine, but vaccination with RRV-1 is associated with significant adverse reactions. © 1986 by The University of Chicago. All rights reserved.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Immunogenicity and safety of live oral attenuated bovine rotavirus vaccine strain RIT 4237 in adults and young children

A candidate oral live rotavirus vaccine, strain RIT 4237, of bovine origin, was tested for immunogenicity and safety in man. In adults the vaccine did not cause clinical symptoms, and a booster response in rotavirus serum antibodies was seen in 2/20 subjects. In seronegative young children one oral dose induced seroconversion to homologous virus in 15/17 (88%) children seronegative by enzyme immunoassay and in 13/19 (68%) children seronegative by a neutralisation assay. The vaccine did not produce gastrointestinal or constitutional symptoms in the children, nor did it cause rotavirus excretion in the stools. The results suggest that the RIT 4237 strain is a promising candidate for a vaccine against human rotavirus, and the vaccine-induced immunity against natural human rotavirus infection should be evaluated in future trials.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

PROTECTION OF INFANTS AGAINST ROTAVIRUS DIARRHOEA BY RIT 4237 ATTENUATED BOVINE ROTAVIRUS STRAIN VACCINE

A randomised, double-blind, placebo-controlled trial was conducted to evaluate the ability of RIT 4237 live attenuated bovine rotavirus (subgroup 1) vaccine strain to protect against natural rotavirus infection in children. 178 infants aged 8 to 11 months received a single oral dose of RIT 4237 vaccine or placebo and were followed up serologically and clinically during a subgroup 2 rotavirus epidemic. No side-effects attributable to the vaccine were observed. During the 5 months' observation after vaccination 2 of the 86 vaccine recipients and 18 of 92 placebo recipients had rotavirus diarrhoea lasting more than 24 h (p<0·001). The vaccine-protection rate was thus 88%. The 2 children in the vaccine group with rotavirus diarrhoea were regarded as primary vaccine failures since they had no detectable serum antibody responses after vaccination. Vaccine prepared from RIT 4237 strain of attenuated bovine rotavirus thus seems to protect children against heterologous subgroup 2 rotavirus diarrhoea. © 1984.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Factors affecting antibody response of newborns to repeated administration of the rotavirus vaccine RIT 4237

The safety and immunogenicity of repeated doses of RIT 4237, an oral live attenuated rotavirus vaccine of bovine origin, as well as the influence of gastric acidity and maternal antibodies on the vaccine 'take rate' were studied in newborns. The vaccine was given orally on the first day of life, at 1 month, and at 2 months of age. Fifty-seven newborns entered the study but only 36 completed the trial. No adverse reaction was observed after vaccination. Immune responses were evaluated by titrating pre- and postvaccination serum antibodies to RIT 4237 by a neutralization technique. Eight of 43 (18.6%) tested infants responded to the first dose of vaccine. Subsequently another six and 11 infants responded to the second and third dose, respectively. The total cumulative response after the third dose was 23 of 36 vaccinees (63.9%). The geometric mean neutralizing antibody titers was lower in responders than in nonresponders before the first dose of vaccine indicating that maternal antibodies interfered with vaccine 'take'. Since the RIT 4237 strain is acid sensitive, gastric pH was measured at the time of each vaccination. Mean pH values in responders were not significantly different than those found in nonresponders. Therefore, vaccine failures cannot be due to inactivation of the rotavirus vaccine in the stomach but instead they can be attributed to high levels of maternal antibodies. At each vaccination, additional subjects seroconverted. Therefore, a multiple dose scheme is advisable to obtain an optimal immune response.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

A rotavirus vaccine for prophylaxis against rotavirus gastroenteritis

Glaxo SmithKline Biologicals. Rixensart, Belgium.University of Tampere. Medical School. Tampere, Finland.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Belém, PA, Brasil.Universidad de Carabobo. Dr. Enrique Tejera. Ciudad Hospitalaria. Insalud, Valencia, Venezuela.Universidad Central de Venezuela. Instituto de Biomedicina. Caracas, Venezuela.Instituto Nacional de Ciencias Medicas y Nutricion. Mexico.Instituto Nacional de Ciencias Medicas y Nutricion. Mexico.KK Women’s and Children’s Hospital. Singapore.Glaxo SmithKline Biologicals. Rixensart, Belgium.Glaxo SmithKline Biologicals. Rixensart, Belgium.The need for safe and efective vaccines to reduce morbidity and mortality caused by rotavirus gastroenteritis in children is weel-known. A live attenuated monovalent ratavirus vaccine (Rotarix) containing human rotavirus strain RIX4414 of G1P1A P[8] specificity is being developed to meet the global need. An overview of RIX4414 trials in developed and developing sttings is presented for 3 selected trials conducted in Finland (pilot study), Latin America (Brazil, Mexico and venezuela) and Singapore involving 5024 infants. The vaccine was well-tolerte, with no increase in any solicited symptoms as compared with the placebo. After 2 doses, 61-91 per cent of vaccineted infants developed rotavirus-specific IgA antibodies. There was no interference with immunogenicity of coadministere routine pediatric vaccines. Rotarix significantly reduced rotavirus gastroenteritis episodes and rotavirus related hospitalizations in vaccinated infants compared wiyh placebo recipients (p0.05), Vaccine efficacy was observed against severe rotavirus gastroenteritis caused by G1 and non-G1 types including the emerging G9 tyoe (p0.05) in Latin America. these results show prospects for widespread us of Rotarix to reduce raotavieus disease burden ans warrant continued worldwide evaluation

Immunogenicity, reactogenicity and safety of human rotavirus vaccine (RIX4414) in Indian infants

Aim: This study was undertaken to assess the immunogenicity, reactogenicity and safety of two doses of an oral live-attenuated human rotavirus vaccine, strain RIX4414 (Rotarix<SUP>TM</SUP>) in an Indian setting. Patients and Methods: Healthy infants (N=363), approximately 8 weeks of age were enrolled to receive two doses of RIX4414 vaccine (n=182) or placebo (n=181) separated by one month. To assess the immune response, blood samples were taken before vaccination and one month post-dose 2 of RIX4414/placebo. Solicited symptoms were collected for 8-days post each dose and safety data was collected throughout the study. Results: The seroconversion rate observed one month post-dose 2 in the RIX4414 group 58.3% [95% CI: 48.7; 67.4] was significantly higher when compared to the placebo group 6.3%; [95% CI: 2.5; 12.5]. The reactogenicity and safety profile was similar for both groups. Conclusions: Two doses of RIX4414 (Rotarix<SUP>TM</SUP>) were immunogenic, had a good safety profile and were well-tolerated when administered to healthy Indian infants