Can someone answer this question about the tetanus vaccine for me?

[bubbleymummy]

How does it work? If having tetanus doesn't give you lifelong immunity then how does the vaccine work? I thought when you got a vaccine your antibodies learn how to fight it off and then 'remember' for the future - same as what happens if you catch the disease. If you can't be immune to tetanus after catching it then how does 'catching' the weakened form in the vaccine work to trigger immunity? Very confused!

Vaccines all have a limited lifespan, I think - just depends on what the pathogen is, as to how long it lasts.

Someone else will know more!

Maybe it's because you have a series of tetanus injections not just one? It used to be that you had to have a tetanus booster every 5 years to be sure you were covered, then they stretched it to every 10 years and then to never! I had one at just the right time, so each time I went back to say I thought I should have a booster, they had changed the rules again and I never needed one!

Another thought - are there different strains of tetanus in nature? If so, you might be immune to one sort but not all of them - the injection might be weakened versions of more than one strain, to be sure your body would recognise any sort. That's just a guess though.