Dr Bob -
My son was sick this summer with what the dr diagnosed as pneumonia (although his chest Xray showed no signs of pnuemonia 3 days into a Zpack while his cough was still HORRIBLE). After his first Zpack, he was still coughing until he threw up. He had 2 more Zpacks, and I finally decided (this was in June/July) last week to have his titers checked (our 16 month old was coughing until vomiting and had one Zpack). The health dept called today to say he had whooping cough. His titer level was 1.8 and anything above 1.1 is considered positive. Do you know if, because we did antibiotics, they will have less immunity? Is is true that they will have immunity for about 5 years? My children are unvaccinated. Also whooping cough had been going around my son's school in March. Do you think that a 1.8 level titer is indicative that he HAD it or that he just developed immunity from being exposed in his school? We're still awaiting titers from the mycoplasma pneumonia. I am unsure if he had both or if he was misdiagnosed altogether.
I don't know what the titer numbers mean (as far as disease immunity versus vaccine or earlier exposure immunity). Regardless, if you think he had the disease (based on the symptoms and the titer), then lifelong immunity is possible (but not guaranteed) and I'd recommend you don't need any more doses.
Just heard back from the doctor's office. His mycoplasma pnuemonia titers were zero. So it looks like this was pertussis. I guess my question at this point is - is there a way to know how long he will have immunity based on his titer level? Does he have less immunity because of doing the antibiotics?