Sir.—I was delighted to read your comments1 on pertussis vaccine in reply to Dr Stewart's letters.2 I agree that pertussis vaccination does reduce the incidence and severity of pertussis. As administration of pertussis vaccine is not without risks, extreme caution must be taken in patients who are at high risk.3,4 I was shocked when I learned that the Wyeth Laboratories, Philadelphia, one of the three companies producing pertussis vaccine in the United States, ceased production of its diphtheria-tetanus-pertussis (DPT) vaccine in June 1984. Wyeth Laboratories' decision was prompted by "uncertainties about and increased cost of insurance coverage, the risk of liability exposure from suits alleging pertussis vaccine injury, and litigation expenses."
Although convulsions, infantile spasms, hypotonic hyporesponsive episodes, encephalopathy, and permanent brain damage have been reported following pertussis vaccination,5 those complications are extremely rare. Griffith reported that the incidence of permanent neurologic damage or death following