Hi Barbara, I don't know if there is anything specific about tetanus infections but in general you acquire immunity for pathogen induced diseases that you survive.

The exceptions are RNA viruses that mutate rapidly like influenza and HIV.

Interestingly, a gene variant of CCR5 (delta-32) in some European populations protected against black death and later against AIDS.

The antibodies produced in the cause of this infection does not last for life so it is better to be vaccinated and to receive booster dose.

@Steingrimur Stefansson @Emmanuel Ifeanyi Obeagu, if I understand Wikipedia and other sources correctly, it seems that natural toxin kills before it can reach the treshold concentration necessary to induce immune response. I am confused by the treshold concentration idea. I understand, the toxin may not get in contact with the correct white blood cells if it is very diluted. However, stochastically, I would expect that sometimes the natural inmunity is induced. (I am not interested in protective ammount of antibodies or lifelong immunity right now). Is my thinking about how immunity wirks correct ? Are there documented data about antibodies in otherwise unvaccinated tetanus survivors ?

Wikipedia: "Unlike many infectious diseases, recovery from naturally acquired tetanus does not usually result in immunity to tetanus. This is due to the extreme potency of the tetanospasmin toxin. Tetanospasmin will likely be lethal before it will provoke an immune response."

Hi Barbara, most foreign proteins (non-self) will generate an antibody response in a healthy individual.

I am not an expert in immunology or toxicology but it is pretty obvious that all of us have been exposed to many pathogens at levels that would kill immuno-compromised individuals.