Can giving several vaccines overwhelm a child’s immune system?

Editorial Board

Editorial Board

March 27th, 2021

Editorial Board

Although children are now immunised against more diseases than ever before, the actual number of antigens (foreign particles) they receive through vaccination is considerably lower.

For example, the old version of the whooping cough vaccine contained around 3,000 antigens whereas the total number of antigens contained in all of today’s childhood vaccines together is around 150.

How can this be? Well, modern vaccines are highly purified, generally containing a single ‘piece’ of the disease-causing pathogen. A child’s immune system is well-equipped to cope with numbers of foreign molecules far greater than this on a daily basis.

In addition, research has turned up no signs that combination vaccines could ‘overload’ the immune system. What is known is that some vaccine components are less efficient in stimulating the immune system when administered as part of a combination. This can result in children needing more separate injections instead of fewer injections with a combination vaccine but, overall, combination vaccines still significantly reduce the total number of injections necessary.

Up to six vaccines (tetanus, whooping cough, polio, diphtheria, Hib, and hepatitis B) can be combined into a single injection. Critics have questioned the need for hepatitis B protection, for newborn babies are unlikely to get it given that the disease is typically transmitted through sexual contact. Experts say hepatitis B in new babies is nearly always very severe and becomes chronic in the vast majority of cases.

There are also purely practical reasons for combining vaccines where appropriate and including hepatitis B. The vaccination rate is generally low in adolescents so the WHO recommends that immunisation be offered at an early age in order to reduce the spread of the disease.

For more information, see ‘Vaccination – 20 Objections & Responses’, produced by the Robert Koch Institute and Paul Ehrlich Institute