Greetings.
These are the few facts which one needs to know about the pertussis;
1) Neither acquisition of the disease nor vaccination provides complete or lifelong immunity. Protection against typical disease wanes/decreases 3-5 years after vaccination and is usually not measurable after 12 years.
2) The majority (almost all) of patients with pertussis who require hospitalization or develop complications are infants. Of the all reported pertussis-related fatalities, 99% are infants.
3) Older children, adolescents, and adults usually have mild or atypical illness.
So your risk for the pertussis is low and for its complications almost negligible. With your history of allergic reaction to it, it is safer to avoid it.
Hope this helps. Please feel free for your follow up questions.
Dr. Arun
I agree there are few different opinion on it. Your 2 year must have been vaccinated with DPT so, chance of you kid getting pertussis is almost nil. With your reaction of respiratory cessation, my opinion would be not to take the risk. There are adult vaccination available but efficacy (transmitting the infection from adult to child) of them is still under observation. So, I don't think there is any risk of your kid getting the infection, in the light of his vaccination.
Doctor (MD)
MBBS, MS (General Surgery), Post-doctoral Fellowship in Sports Medicine