Pneumococcal Conjugate Vaccines for Preventing Invasive Pneumococcal Disease and Pneumonia in Children Under Two Years of Age

A Cochrane review [Abstract] 1 included 11 publications from 6 studies on the pneumococcal conjugate vaccines (PCV) in prevention of invasive pneumococcal disease (IPD) and pneumonia in children under two years of age, with a total of 113 044 subjects. The vaccines used were 7-valent, 9-valent, and 11-valent pneumococcal conjugate vaccine, and as control, either placebo, hepatitis B or meningococcus type C vaccine were given.

Results from pooling HIV-1 negative children from the South African study with the other studies in United States, Philippines, and Finland were as follows: the pooled vaccine efficacy (VE) for vaccine-type IPD was 80% (95% CI 58% to 90%); all-serotype IPD, 58% (95% CI 29% to 75%); for x-ray confirmed pneumonia was 27% (95% CI 15% to 36%); and all-cause mortality, 11% (95% CI -1% to 21%, P = 0.08). Analysis involving HIV-1 positive children had similar findings.

In another cluster-randomised, double-blind trial 2, 47 369 children aged younger than 19 months received 10-valent PCV in 52 clusters or hepatitis vaccine as control in 26 clusters. Infants aged younger than 7 months at the first vaccination received either a 3 + 1 or a 2 + 1 vaccination schedule, children aged 7 - 11 months received a 2 + 1 schedule, and those 12 -18 months of age received a two-dose schedule. 13 culture-confirmed vaccine-type cases of invasive pneumococcal disease were detected: none in the PCV 3 + 1 group, one in the PCV 2 + 1 group, and 12 in the control groups. The estimates for vaccine effectiveness were 100% (95% CI 83 - 100) for PCV 3 + 1 and 92% (58 - 100) for PCV 2 + 1 groups. Two cases of any culture-confirmed invasive disease irrespective of serotype were detected in combined PCV infant cohorts compared with 14 in the corresponding control cohorts (vaccine effectiveness 93%, 75 - 99). In catch-up cohorts, seven cases of invasive disease were reported, all in the control group: two cases in the children enrolled at 7 - 11 months of age; and five cases in children enrolled at 12 - 18 months of age (vaccine effectiveness 100%, 79 - 100). Non-fatal serious adverse events suspected to be vaccine-related were reported via routine post-immunisation safety surveillance in 18 children.

References

• Lucero MG, Dulalia VE, Nillos LT, Williams G, Parreño RA, Nohynek H, Riley ID, Makela H. Pneumococcal conjugate vaccines for preventing vaccine-type invasive pneumococcal disease and X-ray defined pneumonia in children less than two years of age. Cochrane Database Syst Rev 2009;(4):CD004977. [PubMed].
• Palmu AA, Jokinen J, Borys D et al. Effectiveness of the ten-valent pneumococcal Haemophilus influenzae protein D conjugate vaccine (PHiD-CV10) against invasive pneumococcal disease: a cluster randomised trial. Lancet 2013;381(9862):214-22. [PubMed]