Why are Children Vaccinated at Different Ages?

Routine childhood vaccination is an important preventative measure in many parts of the world, and the UK is no exception. The NHS has devised a scheme of immunisations designed to protect children and adults alike from contagious and dangerous diseases. This article looks at why this programme has been designed to provide immunisations at particular ages.

The childhood vaccination timetable

This routine starts when a newly born child is two months old. This is an important point in terms of the immunity of a young child. Babies are born with what are called maternal antibodies, these are important immune molecules that target disease causing pathogens to protect new-borns against the many viruses and bacteria they will encounter after being born.


At two months of age this inherited protection begins to wear off, and this is why vaccination begins at this point. Any vaccines administered before 2 months probably won’t have any effect as those maternal antibodies will probably just clear them from a baby’s system. After 2 months however, vaccines begin to have their desired effect, namely, to induce immunity against particular diseases.

Doses will continue to be administered over the coming months. Many of these will be booster shots of the same vaccine, and these are delivered to effectively ‘top up’ a child’s existing immunity. Certain types of vaccine, mostly inactivated vaccines made up of dead virus or bacteria, need to have follow up booster shots to grant a child lasting immunity against the disease. Again these are timed in such a way that a child’s existing immunity is enhanced by the administration of the booster.

Some vaccines are at later dates, and these are, again, given when they will be most beneficial. The cervical cancer vaccine, for example, an immunisation against the human papillomavirus responsible for most cases of cervical cancer, is given to teenage girls, usually before the age at which they become sexually active. This is because the particular strains of HPV responsible for cancers are usually sexually transmitted. This vaccination routine has vastly reduced incidences of related cancers since its inception, and timing is important in getting the full preventative benefit of the HPV vaccine.

It is extremely important that you follow the NHS’ guidance on when to vaccinate your children. As this article has shown, the timetable has been devised based on studies that show when vaccines can be safely and effectively administered to the benefit of a child’s health.

The childhood vaccination programme will usually have been completed by the age of 18, and the benefits of these immunisations will last a lifetime.


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VACCINATIONS