Hib and pneumococcal vaccines

How it saves lives

Haemophilus influenzae type b and the pneumococcus are bacteria that live harmlessly in many throats but can invade the lungs and the lining of the brain, causing pneumonia and meningitis that kill quickly in small children. Plain versions of these vaccines did not work in babies, whose immune systems ignore them. The breakthrough was to link, or conjugate, the bacteria's sugar coat to a protein the infant immune system does recognise, which finally gave the youngest children real protection.

The story

Pneumonia and meningitis are among the biggest infectious killers of young children, and two bacteria cause much of it. For years the vaccines against them failed in the children who needed them most, because infant immune systems do not respond to the bacteria's sugar coating. Conjugate vaccines solved that, and the effect at scale was enormous. A 2018 study in The Lancet Global Health estimated that Hib and pneumococcal vaccines together saved about 1.45 million children's lives between 2000 and 2015, roughly 1.2 million from Hib and 250,000 from the pneumococcal vaccine. Both are now in routine immunisation across most of the world, though coverage of the pneumococcal vaccine still lags.