Vaccines have a crucial role to play

 

The role of vaccines

Dear Doctor,

I recently had a baby and was handed a vaccines schedule. I was astonished by the number of vaccines my child has to receive by the age of five. I have many questions.

How do vaccines work? Are all vaccines 100 per cent effective? Can babies’ immune systems handle so many vaccines?

Why can’t all the vaccines be combined into one injection and given once?

Why do we have so many vaccines? So if vaccines are effective, why do some require boosters? Can my baby get a disease from the vaccine that’s supposed to prevent it?

Mary

Dear Mary,

Indeed have many questions so let’s tackle this step by step. Today, I will tell you how vaccines work. The idea behind vaccines is what is medically referred to as priming.

Vaccines work to prime your immune system against future “attacks” by a particular disease. Diseases are caused by viruses, bacteria, and fungus; which are medically referred to as pathogens and the protection guards produced by the body against these pathogens are called antibodies.

When a pathogen enters your body, your immune system generates antibodies to try to fight it off.

Depending on the strength of your immune response and how effectively the antibodies fight off the pathogen, you may or may not get sick.

The body, however, remembers, so it keeps what we medically call “memory” of the infection. That means if you do fall ill, some of the antibodies that are created will remain in your body playing watchdog after you’re no longer sick. If you’re exposed to the same pathogen in the future, the antibodies will recognise it and fight it off.

This memory ability of the immune system is the main pillar of how vaccines work. Vaccines are made from a killed, weakened, or partial version of a pathogen.

When your baby gets a vaccine, whatever version of the pathogen it contains isn’t strong or plentiful enough to make him sick, but it’s enough for his immune system to generate antibodies against it.

As a result, the baby gains future immunity against the disease without having gotten sick; and when the baby is exposed to the pathogen again, his immune system will recognise it and be able to fight it off.

Vaccines are designed to generate an immune response that will protect the vaccinated individual during future exposures to the disease. While we all have similar immune system, there are some differences, which in some cases; a person’s immune system will not generate an adequate response.

As a result, he or she will not be effectively protected after immunization. Aware of these subtle differences, vaccines have been tested to provide as high effectiveness as possible.

— Watch out for more on vaccines next week. Dr Ombeva Malande is a paediatrics and child health expert