Infant vaccine drive pays off for SA
IN 2009, South Africa became the first African country to incorporate the pneumococcal conjugate vaccine (PCV) into its routine infant immunisation programme.
And now, five years later, that decision has been proved to have made a significant effect in reducing rates of invasive pneumococcal disease (IPD) – resulting in severe pneumonia or meningitis – including reducing cases caused by antibiotic-resistant bacteria.
Wits University and the National Institute for Communicable Diseases (NICD) released a study: “Effects of Vaccination on Invasive Pneumococcal Disease in South Africa”, which coincided with World Pneumonia Day yesterday.
The study, which has been published in the latest edition of the New England Journal of Medicine, compares invasive pneumococcal disease incidence after the introduction of PCV (2011 and 2012) to incidence prior to its introduction (2005 to 2008).
“The seven-valent (strain) PCV was introduced with the use of a novel three-dose schedule, with two primary doses given to infants at six and 14 weeks of age, and a booster at nine months. In April 2011, a 13-valent PCV replaced PCV7,” the study said.
Researchers used observational data to examine trends in the rates of invasive pneumococcal disease in all age groups in the population before and after the PCV, with stratification according to HIV status.
The study showed a significant decline in invasive pneumococcal disease in children and in adults who had not been vaccinated, which demonstrated the indirect protection as children were the most common carriers.
Through vaccination in children, the disease spread to unvaccinated adults plummeted, the study said.
Among children younger than 2, the overall incidence of invasive pneumococcal disease declined by about 70 percent after the introduction of the vaccine, and the rates of invasive pneumococcal disease caused by bacteria specifically targeted by the vaccine dropped nearly 90 percent.
“This study demonstrates significant declines in IPD cases caused by bacteria resistant to one or more antibiotics, a phenomenon of growing concern among health professionals.
“In fact, the rate of infections resistant to two different antibiotics declined nearly twice as much as infections that could be treated with antibiotics,” the university said in a statement.
The institution said this greater effect of vaccination on antibiotic-resistant strains points to a valuable added benefit of immunisation.
Dr Anne von Gottberg, a clinical microbiologist, head of the centre for respiratory diseases and meningitis at the NICD and lead author of the paper, said yesterday: “We’re really happy. It’s a good story from Africa. Many countries in Africa have introduced or are planning to introduce the vaccine.”