Babies as young as two months of age are immunised against a number of infectious diseases because these infections can be significantly more harmful to infants than to older children. Whooping cough and the Haemophilus influenzae type b (Hib) bacterium are good examples of where early immunisation is seen as essential due to the devastating effect these pathogens can have on babies.
Around a quarter of children who catch whooping cough before they are six months of age can develop serious complications such as pneumonia. In older children, the complications rate falls to around 5%. The cost of waiting until children are older before vaccinating is high.
Giving the first dose of the whooping cough vaccine at the two-month mark can cut the rate of hospitalisation by around two thirds. Babies also receive a booster jab given later in their second year.
Although our intuition might make us inclined to think that infants are less able to tolerate vaccinations than older children, there is no evidence to support this position. Babies born very early – before the 32nd week of pregnancy – are given certain vaccinations because they are particularly vulnerable due to their immature immune systems.
However, as a precaution, doctors typically monitor heart and lung activity after immunisation in order to watch for any complications. Even for such delicate newborns, the evidence suggests that, on balance, the benefit of vaccination outweighs the risk.
Of course, lots of vaccines are not administered at such an early stage. Immunisation against measles, mumps and rubella (MMR) and against meningococci (which cause meningitis) are typically given around the 12-month mark.
For more information, see ‘Vaccination – 20 Objections & Responses’, produced by the Robert Koch Institute and Paul Ehrlich Institute