By Mary Welch

Certiva, a combined diphtheria, tetanus and acellular pertussis (DTaP) vaccine, received approval from the FDA for use in infants and children ages six weeks to seven. The vaccine is manufactured by North American Vaccine, of Beltsville, Md.

"We're really excited about this and we expect the vaccine to do really well," said Stephen Keith, vice president of marketing and sales. "In the 1970s, the search began for a vaccine that would offer protection but have fewer side effects. Certiva represents one of the results of this effort. The medical community is aware of Certiva and anxiously awaiting it."

The vaccine should be available no later than early four quarter, Keith said. It will be marketed in the U.S. by the Ross Products Division of Abbott Laboratories Inc., of Abbott Park, Ill., to private physicians and managed care organizations, and by North American Vaccine to government purchasers.

Traditionally, children were given a DTP vaccine with a whole-cell pertussis component, which resulted in a range of side effects, from redness to fever to seizures.

DTaP vaccine is recommended for administrations at the following ages: two, four and six months; between 15 and 18 months; and between four and six years. Pertussis, or whopping cough, is a respiratory disease caused by the Gram-negative organism Bordetella pertussis. A highly contagious disease, pertussis is responsible for 350,000 deaths in unvaccinated people yearly. Nearly one-third of all adults entering emergency rooms in this country complaining of a chronic cough are diagnosed with pertussis "but they don't whoop," said Keith.

"The traditional vaccine used the whole killed pertussis bacteria. It effectively reduced the incidence of pertussis, but there were high rates of adverse effects," Keith noted.

Instead, North American Vaccine uses only pertussis toxin that is inactivated using hydrogen peroxide. The inactivated pertussis toxin (know as a toxoid) induces protection against the disease with fewer side effects, especially the more severe ones that are associated with the whole cell DTP vaccine.

Swedish Trial Studies Vaccine During Epidemic

"The demonstrated efficacy for Certiva in Sweden was especially significant since the study was done during an epidemic of pertussis," said Keith. "The trials, both done in the U.S. and Europe, show Certiva to be safe and efficacious. These trials were done with thousands of children. In one project, we are vaccinating 60,000 infants and children in Goteborg, Sweden. We're very confident of this product."

North American Vaccine has 15 vaccines in its pipeline, with three in advanced stages.

In June, the FDA's Vaccines and Related Biologicals Advisory Committee agreed with the company that safety and immunogenicity studies alone on the acellular pertussis vaccine would be sufficient to warrant an indication for adolescent and adult booster doses. This vaccine has finished Phase II trials and a product license application will be filed by late 1998 or early 1999, Keith said.

"This is important because, not only will it reduce the number of adults and adolescents getting pertussis, but because it is so contagious, it will reduce the number of children exposed as well," he said.

The second vaccine, now in Phase II/III trials, is a DTaP vaccine combined with an inactivated polio virus (IPV) vaccine. The vaccine is already approved in Denmark and in June received clearance from the European Committee for three other member countries.

The third vaccine, now in Phase II in the U.K. and labeled a British "fast track vaccine," is intended to prevent group C meningococcal infection, the leading cause of bacterial meningitis in children and young adults, with an estimated 2,600 cases yearly and a mortality rate estimated as high as 15 percent. Soon after completion of trials in the U.K., the company will start trials in the U.S.

SmithKline Beecham plc, of London, received FDA approval for its DTaP vaccine, Infanrix, last year. Two other companies have DTaP vaccines on the market. Tripedia is the vaccine marketed by Connaught Laboratories Inc., of Swiftwater, Pa., a subsidiary of Rhone-Poulenc Group, in Paris. Wyeth-Lederle Vaccines and Products, of Radnor, Pa., a division of American Home Products Corp., of Madison, N.J., received FDA approval for its vaccine, Acel-Imune, in December 1996.

Chiron Corp., of Emeryville, Calif., has a DTaP vaccine on the market in Europe and is awaiting FDA approval.

North American Vaccine reported the FDA clearance Thursday. Its stock (AMEX:NVX) closed Friday at $14, down $0.312. *