PPV23 provided no protection against IPD in at-risk children

New study findings revealed that only 25% of children older than 2 years with comorbidities who developed invasive pneumococcal disease had received the 23-valent pneumococcal polysaccharide vaccine.

However, there was no evidence of protection against the serotypes included in the 23-valent pneumococcal polysaccharide vaccine (PPV23) among children who received the vaccine, according to the study findings published in Clinical Infectious Diseases.

Shamez N. Ladhani, MRCPCH, PhD, of the immunization, hepatitis, and blood safety department at Public Health England, and colleagues distributed a survey to general practitioners on children aged 5 to 15 years with laboratory-confirmed invasive pneumococcal disease (IPD) from July 2009 to June 2011.

In the United Kingdom, patients aged at least 2 years at increased risk for IPD have been offered PPV23 since 1992.

During the study period, 447 IPD cases occurred in 439 patients. More than one-quarter of patients had comorbidities and one-third of the children were immunocompromised, had chronic respiratory disease or other comorbidities. Thirty-four patients with chronic respiratory disease developed pneumonia.

PPV23 was administered to 26.6% of patients with comorbidities; however, IPD caused by vaccine serotypes was not associated with prior PPV23 vaccination (adjusted OR=1.09; 95% CI, 0.36-3.32).

“Irrespective of this observation, the evidence for a protective effect of PPV23 in at-risk children remains poor and we cannot comment on PPV23 effectiveness in healthy children,” the researchers wrote. “Clinicians contemplating offering PCV13 to at-risk children instead of PPV23, however, need to consider that there are only about 20 laboratory-confirmed PCV13-IPD cases annually in England and Wales among at-risk 5- to 15-year-olds, that PCV13-type IPD should decline in all age groups through herd protection and the cohort of children immunized with PCV13 in infancy will increase every year and soon enter the 5- to 15-year age group.”

In an accompanying editorial, Stephen I. Pelton, MD, who is a professor of pediatrics and epidemiology at Boston University Schools of Medicine and Public Health, wrote that PPV23 use in the United Kingdom has been limited despite guidelines that encouraged use in children older than 5 years with at-risk and high-risk conditions.

“Pneumococcal disease remains a concern specifically in children with comorbid illnesses, both immunocompromising conditions as well as chronic heart, lung, kidney and neurologic disease,” Pelton told Infectious Diseases in Children. “Clinicians should have high levels of vigilance in such children for pneumococcal disease when they present with a compatible clinical picture. PPV23 is recommended by both US and UK public health authorities for use in high-risk and at-risk children. However, insufficient data is available to be confident about the effectiveness of PPV23 against IPD or nonbateremic pneumonia due to the serotypes unique to PPV23 (compared to PCV13).” — Amber Cox

Stephen I. Pelton, MD, can be reached at Maxwell Finland Laboratory for Infectious Diseases, Boston Medical Center, 670 Albany Street, Boston, MA 02118.

For more information:

Ladhani SN. Clin Infect Dis. 2013;doi:10.1093/cid/cit791.

Pelton SI. Clin Infect Dis. 2013;doi:10.1093/cid/cit792.

Disclosure: See study and editorial for a full list of disclosures.