A new study, “Antibiotic Use and Vaccine Antibody Levels,” in the May 2022 Pediatrics (published online April 27) finds that vaccine-induced antibody levels, which protect children from getting sick, were lower in children who were given antibiotics early in life. Researchers in Rochester, N.Y., studied 560 children, ages 6-24 months, comparing blood vaccine antibody levels of 342 children with antibiotic prescriptions against 218 who hadn’t received antibiotics. The study found that the toddlers who were given antibiotics were more likely to have antibody levels under the level of protection compared with children with no antibiotic prescriptions. The impact seems dose dependent, meaning when more antibiotics were given there was a greater reduction of antibody levels. Treatment with broad-spectrum antibiotics, longer duration of therapy and more antibiotic courses during the first year of life were associated with blood antibodies more frequently below the level of protection. For example, after each antibiotic course the child received, antibody levels for the diphtheria, tetanus, and pertussis (DTaP) vaccine were reduced 5.8%; Haemophilus influenzae b (Hib) vaccine antibodies were reduced 6.8%; polio vaccine antibodies were reduced 11.3%; pneumococcal conjugate (PCV) vaccine antibodies were reduced 10.4% for un-boosted vaccinations; and the antibodies were reduced by 12.2% to 21.3% post boosters. The study also found that children in daycare were more likely to have taken antibiotics—42.7% of the group given antibiotics were in daycare compared to 20.6% who hadn’t received any antibiotics. The authors also noticed that race and ethnicity were associated with the frequency of antibiotic prescriptions. Researchers concluded that these results provide new evidence suggesting caution regarding over-prescription of antibiotics to prevent against outbreaks of vaccine-preventable disease. More research is needed with more children with more frequent antibody testing to understand vaccine immunity in young children receiving antibiotics.
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The American Academy of Pediatrics is an organization of 67,000 primary care pediatricians, pediatric medical subspecialists and pediatric surgical specialists dedicated to the health, safety and well-being of infants, children, adolescents and young adults.