‘Vaccines are the tugboats of preventive health’ – William Foege
Vaccines, shots, immunization – so many names for this agent of childhood trauma. But apart from making little kids terrified of anyone with a stethoscope, why do we need vaccines anyway?
Well, diseases are caused by various micro-organisms, like viruses and bacteria. When the micro-organisms breach the body’s initial defences (like the skin) and infect the body, the body fights back internally with its own arsenal of defence mechanisms that it creates, and eventually beats off the infection.
Vaccines have a weakened form of those micro-organisms, so when you get vaccinated, you get infected with a little bit of a weakened form of the virus — not enough to actually get you sick, but enough for your body to recognise the virus and equip itself to fight it off when it actually hits you.
It’s like taking a self-defence class. You take the class and you might get a few bruises as you learn the moves to fight off an attacker; but, at the end of it, you’ve learnt exactly how to defend yourself. But what if you didn’t take the class? You won’t know where to hit, what to do – you’d be defenceless. The mugger could rob you; injure you so severely that you’d have permanent damage, or you might even die.
Vaccines are the self-defence class for your body’s immune system. It’s the dress rehearsal before the main event, so your body has everything in place to deal with the actual full-strength virus.
And vaccines aren’t just important at the individual level; they help the population as a whole. There’s this concept called “Herd Immunity”. Let’s say, for example, there’s a room of 50 people — all unvaccinated — and someone walks in with a dangerous disease. The infection will spread from person to person until the entire room is infected. But what if everyone in the room were vaccinated, except for 5 people near the door and 3 people furthest from the door? Well, the 5 people near the door would be infected, but it won’t spread to anyone else; it’ll never reach the 3 other unvaccinated people, because the 42 vaccinated people between them and the door acted as a buffer, preventing the disease from spreading.
And if you apply that concept to the entire population, if enough of us are vaccinated, we’ll be able to control the spread of disease, protecting those people who cannot be vaccinated. And who are those people? Well there are some people who are born without a functioning immune system; they can’t even fight off the weakened virus in the vaccine. Cancer patients on chemotherapy can’t get vaccinated because the chemotherapy weakens their immune system too much for them to be able to tolerate the vaccine. That’s why herd immunity is so important. It’s like when a herd of elephants are under attack: the adults gather in a circle around their young to protect them. That’s what we do when we’re vaccinated: we help to protect those who can’t be vaccinated.
Vaccines can also help to prevent cancer. Cervical cancer is highly linked with HPV. There’s a vaccine against HPV, making cervical cancer one of the most preventable types of cancer. This is good news to us women, and we ought to take advantage of this.
I received three vaccines last week. I finally got around to getting my chicken pox and HPV vaccines; and, for the first time, I got a flu shot. So when I exhort all of you to make sure you’re up-to-date on your vaccines, I’m not all talk; my still-sore arms can attest to that!