The rotavirus vaccine introduced in Mexico in 2007 still appears to be preventing diarrhea-related deaths in children, despite speculation that years later the vaccine may not be as effective.
In a letter released Wednesday in the New England Journal of Medicine, researchers report that the vaccine still seems to be successful in reducing mortality rates among children. They compared diarrhea-related deaths during the three years after the vaccine was introduced with death rates during rotavirus seasons from 2003 to 2006.
The rotavirus disease is responsible for 527,000 childhood deaths per year.
The decline in diarrhea-related deaths was maintained for three years for children younger than 5. Diarrhea-related deaths fell by 56% during rotavirus seasons after children were vaccinated, compared with earlier years before the vaccine was introduced nationally.
From 2007 to 2008, most of the declines were seen among children younger than 1 year, but in ensuing seasons older children were included. In children under age 5, diarrhea-related deaths decreased by 46%, from an average of 18 deaths per 100,000 from 2003 to 2006 to nine deaths per 100,000 from 2008 t0 2010. That represents a drop of about 880 deaths per year.
The authors noted that the decrease in death rates due to diarrhea continued for three seasons after the vaccine was introduced shows that some of the drop in mortality rates is probably due to the vaccinations.
The letter concludes, "The cumulative reduction of some 2,640 childhood deaths since the vaccination program was initiated in Mexico highlights the lifesaving promise of rotavirus vaccines and supports the World Health Organization recommendation for immunization of all children worldwide against rotavirus."