THE VALUE OF THE PEDIATRIC heptavalent pneumococcal conjugate vaccine (PCV7) in preventing pneumococcal meningitis has been confirmed by a study, the results of which were recently published in the New England Journal of Medicine. The findings reiterate data that were reported by the CDC and published in Morbidity and Mortality Weekly Report a year ago.
The research team, headed by Lee H. Harrison, MD, at the University of Pittsburgh School of Medicine, reviewed 1379 cases of pneumococcal meningitis in children and adults from 1998 to 2005. They found an overall 30.1% decline in the incidence of pneumococcal meningitis between years 1998 to 1999 and 2004 to 2005. More striking findings were noted in special populations: a 64% decline in incidence was seen among children younger than 2 years, and a 54% decline was seen in persons 65 years and older. The decline was attributed to the introduction of the PCV7 vaccine in 2000.
In a statement to the press, Harrison stressed that immunization of children against pneumococcal disease is protective for society at large. “[Immunized children] are much less likely to carry pneumococcal strains covered by the vaccine in the back of the throat. They don’t end up transmitting them to other children, their parents, and grandparents,” he said.
With this promising data, however, another challenge was uncovered. While disease attributed to PCV7-susceptible serotypes declined, pneumococcal disease attributed to other serotypes (specifically 19A, 22F, and 35B, including antibiotic-resistant strains) increased—and the increase is significant, according to the authors of the study. Serious effort must now be turned toward control of the causes of pneumococcal infection.
The citations for these studies are the following:
•Hsu HE, Shutt KA, Moore MR, et al. Effect of pneumococcal conjugate vaccine on pneumococcal meningitis. N Engl J Med. 2009;360:244-256.
•Centers for Disease Control and Prevention. Invasive pneumococcal disease in children 5 years after conjugate vaccine introduction—eight states, 1998-2005. MMWR. 2008;57:144-148.