Vaccines

No, combination vaccines don’t overwhelm kids’ immune systems

No, combination vaccines don't overwhelm kids' immune systems
Parents are concerned combination vaccines, which protect against several diseases at once, can be too much for a young immune system to cope with. Credit: www.shutterstock.com

No parent likes seeing their child have injections. Yet, around 93% of parents across Australia protect their children against 15 serious diseases by giving them all the recommended vaccines on the National Immunisation Program Schedule. This success is due in part to the value of combination vaccines, which protect against two or more diseases in one go.

Combination vaccines mean kids need fewer injections overall. By adding several antigens (the part of the germ that stimulates the immune system) together in one vaccine, we can protect kids against up to six diseases in a few shots. These shots are typically given in a series of two or three injections over time.

Our new study released today in JAMA Pediatrics, backs the safety of a four-in-one combination vaccine – designed to protect against measles, mumps, rubella and varicella (chickenpox) and known as the MMRV vaccine. We also show its added benefits in protecting kids by the time they reach pre-school.

Making a combination vaccine typically involves decades of research to ensure the precise balance of “active” components is included, the immune response to each component is effective, and even the slightest change in a vaccine doesn’t change its safety profile.

This is stringently regulated across the world, by groups such as the Therapeutic Goods Administration in Australia and Food and Drug Administration in the USA, before a vaccine is even trialled in humans, or indeed ultimately licensed for use.

Once these combination vaccines are used, their safety (as well as the safety of other vaccines) is also actively monitored. One new way we do this in Australia is by monitoring any side-effects in real time. Parents respond to an SMS survey about their child’s recent vaccination, the results of which are collated and posted online.

Too much to handle?

However, some parents question if giving an injection that protects against multiple diseases will overwhelm the immune system or be too much to handle. The answer is “no” for many reasons.

A review into parental concerns about combination vaccinations confirms the moment babies enter the world they are covered in millions of foreign germs. The infant immune system is no longer considered “immature” but is finely tuned to respond to the incredible number of viruses, bacteria and other…