Vaccine
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Randomized Controlled Trial Multicenter Study
Secondary efficacy endpoints of the pentavalent rotavirus vaccine against gastroenteritis in sub-Saharan Africa.
The efficacy of the pentavalent rotavirus vaccine (PRV), RotaTeq(®), was evaluated in a double-blind, placebo-controlled, multicenter Phase III clinical trial conducted (April 2007-March 2009) in 3 low-income countries in Africa: Ghana, Kenya, and Mali. In total, 5468 infants were randomized 1:1 to receive 3 doses of PRV/placebo at approximately 6, 10, and 14 weeks of age; concomitant administration with routine EPI vaccines, including OPV, was allowed. HIV-infected infants were not excluded. ⋯ There was a trend towards higher VE with higher disease severity, although in some cases the numbers were small. In African countries with high under-5 mortality rates, PRV significantly reduced RVGE through nearly 2 years of follow-up; more modest reductions were observed against gastroenteritis of any etiology. PRV provides protection against severe-RVGE caused by diverse rotavirus genotypes, including those not contained in the vaccine.
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Diarrhoeal disease is one of the commonest causes of death in children, especially in developing countries in Africa and Asia. Rotavirus has been consistently identified as the commonest pathogen associated with severe diarrhoea. Hence, the availability of vaccines against this organism provides the opportunity to reduce child mortality. ⋯ Additional research is required to improve understanding on the performance of these vaccines in developing countries in Africa and Asia and measures that may improve performance. Data that will assist in the definition of the optimal immunization schedule and possibly allow relaxation of the age restrictions for vaccine use may help in enhancing the impact of the vaccines in these countries. Finally, disease surveillance and studies are required to document the impact of vaccination and monitor changes in disease epidemiology.
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Randomized Controlled Trial Multicenter Study
Efficacy of human rotavirus vaccine against severe gastroenteritis in Malawian children in the first two years of life: a randomized, double-blind, placebo controlled trial.
Rotavirus gastroenteritis is a major cause of morbidity and mortality among African infants and young children. A phase III, placebo-controlled, multi-centre clinical trial of a live, oral G1P[8] human rotavirus vaccine (RIX4414) undertaken in Malawi and South Africa significantly reduced the incidence of severe rotavirus gastroenteritis in the first year of life. We now report on vaccine efficacy in the Malawi cohort of children who were followed into the second year of life. ⋯ There were non-significant trends towards a higher efficacy in the second year of life among children who received the three-dose schedule compared with the two-dose schedule, and a higher anti-rotavirus IgA seroresponse rate in the three-dose RIX4414 group. Rotavirus strains detected included genotype G12 (31%); G9 (23%); and G8 (18%); only 18% of strains belonged to the G1P[8] genotype. While the optimal dosing schedule of RIX4414 in African infants requires further investigation, vaccination with RIX4414 significantly reduced the incidence of severe gastroenteritis caused by diverse rotavirus strains in an impoverished African population with high rotavirus disease burden in the first two years of life.
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Randomized Controlled Trial Multicenter Study
Efficacy and immunogenicity of two or three dose rotavirus-vaccine regimen in South African children over two consecutive rotavirus-seasons: a randomized, double-blind, placebo-controlled trial.
Human rotavirus vaccine (HRV; i.e., Rotarix) reduced the incidence of severe rotavirus gastroenteritis (RVGE) by 77% (95% Confidence interval: 56-88%) during the first year of life in South Africa. Persistence of HRV-derived protection against RVGE during subsequent rotavirus seasons, although evident in industrialized settings, remains to be established in African settings. This study reports on the efficacy of HRV against severe RVGE over two consecutive rotavirus seasons in South African children. ⋯ Rotarix is associated with significant reductions in severe gastroenteritis episodes through 2 years of life among South African children. Further research is needed to determine the optimal dosing schedule of Rotarix in providing long-term protection against rotavirus illness in African children.
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Randomized Controlled Trial Multicenter Study
Analyses of health outcomes from the 5 sites participating in the Africa and Asia clinical efficacy trials of the oral pentavalent rotavirus vaccine.
Efficacy of the pentavalent rotavirus vaccine (PRV), RotaTeq(®), against severe rotavirus gastroenteritis (RVGE) was evaluated in two double-blind, placebo-controlled, multicenter Phase III clinical trials conducted in GAVI-eligible countries in Africa (Ghana, Kenya, and Mali) and in Asia (Bangladesh and Vietnam) from March 2007 through March 2009. The findings from each continent have been analyzed and presented separately, according to a single identical protocol. Ad hoc analyses combining data from the five sites were performed to further assess the impact of PRV. ⋯ Combining data from the 5 sites strengthens the precision of VE estimates and reveals rising VE with increased RVGE severity. Extrapolating data from VE against severe GE and RVGE suggest that 39% of severe GE episodes during the first year of life were due to rotavirus, highlighting substantial, potentially preventable, public health burden of RVGE. PRV provides protection against non-vaccine serotypes (G8P2A[6]).