It is very common to give antibiotics to babies in order to treat a bacterial infection, such as a urinary infection. But new research has warned that babies and toddlers who were given antibiotics might have a less vigorous immune response to routine childhood vaccinations. This is the first of its kind suggestion made by a study that hints antibiotics might dampen the ability of babies and toddlers to generate infection-fighting antibodies in response to vaccination.
However, experts are of the view that more research is necessary, and it is not clear whether the use of antibiotics is linked to higher rates of breakthrough infections.
But the study supports findings of earlier work, in lab animals and one study of adults, that antibiotics could hinder antibody production: The drugs temporarily kill off some of the beneficial bacteria that live in the gut, and those bugs play a key role in immune function.
Babies typically get different vaccines in the first six months of life and get boosters in their second year. For the study, the author collected blood samples from 560 children in the age group of 6 to 24 months during routine visits with their pediatricians, measuring antibody levels after they received polio, diphtheria-tetanus-pertussis, Haemophilus influenzae type b, and pneumococcal vaccines.
Of these children, 342 had collectively been prescribed close to 1,700 courses of antibiotics. The other 218 children had not received antibiotics. The team analyzed whether antibody levels induced by the four vaccines met the threshold of what is considered protective and found that at 9 and 12 months old, children who had received a course of antibiotics were significantly more likely to have subpar levels of antibodies than those who had not. The immune response was lower among children who’d had multiple courses of antibiotics than for those who’d had one, with each antibiotics dose associated with 5 to 11 percent lower antibody levels after initial vaccinations and 12 to 21 percent lower antibodies after booster shots.