A new study from a collaboration between the Gambian government, the Medical Research Council (MRC) of the United Kingdom, and partners such as the London School of Hygiene & Tropical Medicine, demonstrated for the first time the impact of introducing pneumococcal conjugate vaccines (PCV) in a low-income country.
The Gambia PCV program had a significant impact on child health, reducing by 55 percent the incidence of pneumococcal pneumonia, meningitis, and sepsis.
The research article, “Effect of the introduction of pneumococcal conjugate vaccination on invasive pneumococcal disease in The Gambia: a population-based surveillance study,” was published in the journal The Lancet Infectious Diseases.
Pneumococcal diseases, caused by infection with the bacterium Streptococcus pneumoniae, include conditions with a range of severity, from ear and sinus infection to potentially fatal pneumonia, sepsis, and meningitis. Although pneumococcal diseases are a cause of morbidity and mortality worldwide, the rates of disease and death are much higher in developing countries, especially in the most fragile age groups: children and the elderly.
There are more than 90 serotypes, although only a few are known to cause disease. Pneumococcal conjugate vaccines (PCVs), which target the most prevalent serotypes in a safe and effective manner, are currently recommended to be included in childhood immunization programs worldwide.
The World Health Organization (WHO) specifically highlights the importance of these vaccines in countries with high childhood mortality. However, despite the high priority, there is still little information available about the impact of PCVs in low-income countries.
According to a news release, researchers used population surveillance tools to investigate the impact of pneumococcal disease by introducing two vaccines, the 7-valent vaccine (PCV7) introduced in August 2009, and the 13-valent vaccine (PCV13) introduced in May 2011.
Researchers monitored children age 2 months or older, enrolling in the investigation 14,650 patients in whom the scientists identified 320 cases of invasive pneumococcal disease during the follow-up period. After comparing to baseline observations, the incidence of invasive pneumococcal disease decreased by 55 percent in the age 2 months to 23 months age group, and by 56 percent in the age 2 years to 4 years group.
Researchers believe that these preliminary results corroborate the substantial benefit of PCVs in low-income and middle-income countries, significantly reducing invasive pneumococcal disease, and stressed the importance of continued advocacy for these vaccines, assuring developing countries which have not yet introduced them that PCVs are a safe and effective bet for childhood health and survival, and also for the economy of the healthcare system.