CONNAUGHT’s TRIPEDIA ACELLULAR PERTUSSIS VACCINE APPROVED FOR DTP IMMUNIZATION STARTING AT 15 MONTHS; FIRM PREDICTS LIMITED INITIAL SUPPLY

Connaught's Tripedia diphtheria, tetanus toxoids and acellular pertussis vaccine is indicated for the fourth or fifth booster dose of the five-part DTP series in children. Final labeling, approved by FDA on Aug. 20, states that Tripedia is indicated "for immunization of children 15 months to seven years of age (prior to seventh birthday) who have previously been immunized against diphtheria, tetanus and pertussis with three or four doses of whole-cell pertussis DTP vaccine." Tripedia is the second acellular pertussis vaccine approved by FDA. The agency cleared the Lederle-Praxis acellular pertussis vaccine Acel-Imune last December ("The Pink Sheet" Dec. 23, 1991, T&G-1). The Connaught vaccine is specifically indicated for use in 15 month-old children. Lederle's Acel-Imune is indicated for children from 17 months with the proviso that it may be considered for children as young as 15 months "when it is expected that the child will not return at 18 months." Connaught's clinicals included studies in the 15-17 month age group, while Lederle's did not. The acellular pertussis components of the vaccine are produced in Japan by Biken (The Research Foundation for Microbial Diseases of Osaka University). Biken received an establishment license approval for manufacturing and importation on Aug. 20. Acellular pertussis vaccines have been marketed in Japan since 1981 for vaccination of two-year-old children. Biken's acellular pertussis vaccine concentrate is combined with Connaught's diphtheria and tetanus toxoids for production of the final vaccine in the U.S. The acellular pertussis concentrate for Tripedia is composed of two antigens, pertussis toxoid and filamentous hemagglutinin, compared to the Lederle vaccine, which is composed of four components. Connaught's cost for the vaccine to pediatricians is expected to be $11.36 per dose or $170.40 per 7.5 ml bottle. Lederle's current price to wholesalers and physicians is $15.60 per dose or $156 per 5 ml bottle. The companies are likely to set lower prices to compete for federal vaccine program contracts. Connaught said it will begin shipping the vaccine in the next few days but supplies may be limited due to a three month lag time between ordering the acellular pertussis concentrate from Biken and manufacturing the final product in the U.S. Advertising for the vaccine will be handled by William Douglas McAdams (see T&G- 5.) Like Acel-Imune, Connaught's acellular pertussis vaccine reduces the severity of adverse reactions compared to whole-cell pertussis vaccine. Labeling states that "when compared to [Connaught's] whole-cell pertussis DTP vaccine, Tripedia produced fewer and milder local reactions such as erythema, swelling, and tenderness at the injection site; as well as fewer and milder systemic reactions such as fever, irritability, drowsiness, vomiting, anorexia and high-pitched unusual cry." Connaught filed the applications for Tripedia (PLA 90-0352, 90-0353) in July 1989. Data included findings from a trial sponsored by the Swedish government of 1,389 children aged six to 11 months. A three-year follow-up of that trial showed a protective efficacy of 77% for all culture-proven cases of pertussis and an efficacy of 92% for children with positive pertussis cultures and coughs greater than 30 days in duration, labeling notes. Data from two randomized, double-blind, placebo- controlled U.S. trials in about 3,200 children aged 15-20 months and four-to-six years shows similar efficacy for Tripedia. The PLA was recommended for approval by FDA's vaccines advisory committee last November ("The Pink Sheet" Nov. 18, 1991, p. 18). Both Connaught and Lederle have begun Phase III trials with the acellular pertussis components of their vaccines in children under six months of age ("The Pink Sheet" April 27, p. 5). Connaught's trial, which is being conducted by the National Institute of Allergy and Infectious Diseases, will enroll 10,000 children in a comparison of acellular and whole-cell pertussis vaccines. Lederle is recruiting 8,000 children for a a trial based in Munich.