New evidence on rotavirus and pneumococcal vaccine disease impact, safety and dosing optimization were presented by the AVI-TAC Special Studies consortium and partners
Copyright UNICEF/2008/Shehzad Nooran
New evidence on rotavirus and pneumococcal vaccine disease impact, safety and dosing optimization were presented by the AVI-TAC Special Studies consortium and partners.
Data from Kenya, South Africa, Nicaragua, and Bolivia, all studies supported by the GAVI Alliance, provided compelling evidence for the effectiveness of these vaccines in routine use settings and focused attention on the remaining issues for vaccine impact optimization.
Rotavirus vaccine studies from early use countries in Latin America confirm the effectiveness of both licensed rotavirus vaccines against severe rotavirus diarrheal disease.
Because of the higher rates of rotavirus diarrheal disease in GAVI country settings, the absolute reduction in rotavirus disease from use of the vaccine is well beyond that of developed countries where the effectiveness of the vaccine is somewhat higher.
There was evidence across a range of studies showing that rotavirus vaccines confer cross-protection to strains not represented in the vaccine.
A review of Mexican diarrheal mortality data following introduction of rotavirus vaccine shows that the mortality reduction observed is persistent across multiple years of observation, lending confidence to the inference that this is vaccine associated.
Pneumococcal conjugate vaccine impact assessments in Kenya reveal over a 90% reduction in the burden of vaccine serotype pneumococcal disease following PCV introduction into the routine immunization schedule in 2011.
In South Africa where a novel PCV dosing schedule was evaluated for vaccine effectiveness (2 primary infant doses and a 9 month booster) showed vaccine performance among HIV-negative children similar to the high efficacy seen during the randomized trial in South Africa.
However, among HIV-infected children the regimen effectiveness was lower than expected, resulting in a recommendation that this 2+1 regimen may be insufficient for HIV-infected children.
A safety evaluation in Kenya of the 2-dose PCV10 product without preservative showed no increased risk of local injection reactions.
Finally an analysis of all available serotype replacement data concluded that in those settings with long-term use of PCV, and long-term surveillance, the modest degree of serotype replacement is significantly smaller than the reductions in vaccine serotype disease resulting in a sustained net reduction in overall pneumococcal disease among children less than 5 years over the 7 years of PCV program use.