Impact of Childhood Vaccination on Racial Disparities in Invasive Streptococcus pneumoniae Infections. Flannery B, Schrag S, Bennett NM, Lynfield R, Harrison LH, Reingold A, Cieslak PR, Hadler J, Farley MM, Facklam RR, Zell ER, Whitney CG, for the Active Bacterial Core Surveillance/Emerging Infections Program Network. JAMA 2004;291:2197-2203
Explanatory note: In the past, the incidence of invasive pneumococcal disease has been higher among blacks than among whites in the United States. Since October 2000, when a 7-valent pneumococcal conjugate vaccine (Prevnar) became available for children, the number of new cases of serious pneumococcal disease in young children has declined dramatically.
What has been the effect of the pneumococcal conjugate vaccine on the rates of pneumococcal disease cases among whites and blacks in the United States?
Researchers analyzed data from seven states on serious pneumococcal infections and sorted the data by age and race. The seven states were California, Connecticut, Georgia, Maryland, Minnesota, New York, and Oregon. Pneumococcal infections were confirmed by laboratory tests.
They then compared the rates for pneumococcal diseases by age and race, before and after the introduction of the conjugate vaccine. They also estimated vaccination coverage in each racial group using the National Immunization Survey.
The study found that the number of new cases of serious pneumococcal disease diagnosed every year decreased for both blacks and whites, when the two years before vaccine were compared to the first two years of widespread vaccine use.
Before the vaccine became available, blacks had almost three times more cases than whites. In 2002—two years after the vaccine was introduced—blacks had only two times more cases than whites. The greatest reductions were among children younger than 2 years.
The researchers also found that by 2002, 74% of white children and 68% of black children aged 19 to 35 months in the 7 states had received at least 1 dose (out of 4) of pneumococcal conjugate vaccine; 43% of white and 39% of black children received 3 or more doses.
The rates of serious pneumococcal disease have fallen dramatically in the first two years of widespread use of the new pneumococcal conjugate vaccine. Declines were greater among black children than white children, despite similar rates of vaccine use.
The rates of serious pneumococcal infection have declined among all children. Although black children remain at higher risk of invasive pneumococcal disease than white children, the introduction of childhood pneumococcal vaccination has reduced the racial disparity in incidence of pneumococcal disease despite serious shortages of vaccine. Rates of serious pneumococcal infection are very high among some Native American groups; it would be important to learn whether they are experiencing a similar decline in disease as well.
Before the vaccine was available, black infants and children were at substantially greater risk—sickle cell disease contributed to this increased risk in part—than white children for pneumococcal disease. Since the black children respond well to the conjugate vaccine, it was hoped that the racial disparity would be diminished—the data now indicates that this is so.