Following positive results from studies in Asia and Africa on the efficacy of rotavirus vaccines in preventing severe rotavirus gastroeneteritis (RVG), international health experts are promoting the distribution of the vaccine in both continents. RVG causes diarrhea, vomiting and fever, and is responsible for the deaths of about half a million children around the world each year.
In a clinical efficacy trial in Bangladesh and Vietnam of Merck s RotaTeq, the vaccine efficacy was calculated to be 48 percent after a two-year follow-up of 2,036 infants aged 4-12 weeks. A randomized-controlled trial of the same vaccine on 5,468 children aged 4-12 weeks in Ghana, Kenya and Mali produced a vaccine efficacy of 39 percent. (RotaTeq, incidentally, is co-developed by Dr. Paul Offit, an ACSH trustee and chief of Infectious Disease at Children s Hospital of Philadelphia).
The good news is that these numbers represent the worst-case scenario, says ACSH s Dr. Gilbert Ross. If these vaccines were distributed widely, as they should be, then transmission of RVG would be even lower due to herd immunity.
In a related story further demonstrating the vital public health impact of vaccinations, the resurgence of polio has been reported in Tajikistan, the former Soviet republic. The recent outbreak thwarts efforts to globally eradicate the debilitating disease. There have been 452 documented cases of polio in Tajikistan since February, indicating its spread from Africa and South Asia where it has been isolated for the majority of the past decade. Four major immunization drives have considerably slowed the pace of new infections, but disease investigators caution it s too soon to declare the outbreak over.
Dr. Ross further reiterates the importance of vaccines in eliminating disease outbreak. The fact that we re now seeing polio cases in Russia and Central Asia is a bad sign. Vaccines would prevent this catastrophe, and public health authorities have to mobilize now more than ever to end this for good.