MyRosie, the daycare said it was the first year they had Pertussis. According to my pediatrician, even though infants are vaccinated against it (at 2, 4 and 6 months), the vaccine is not 100% effective. What is effective though is taking a small dose of antibiotics as soon as you find out your child has been in contact with a sick one.
Thank you for your replies Duxxy, MRD and Canuck. I was frustrated that I couldn't find any info on the net and made a call to the doctor who followed me throughout my pregnancy. I really value his opinion (not that I don't that of the pediatrician; I just needed a second opinion). He said that it is a good vaccine, BUT he's not a big defender of it as of now. He might change his mind next year when there is more data on it, but he thinks that all it does is reduce the strength of the "disease" so that kids spend less time in the hospital. His opinion is that is should target a specific audience, like premature babies and babies born in an environment where parents are more ignorant of cleansiness. As I don't fit the bill, I think I will just skip this one.