Clinical studies of component ("acellular") pertussis vaccines have been undertaken in recent years, and several acellular vaccines have been used in Japan for 10 years. The Committee has reviewed these trials and related data and herein provides its assessment regarding the current status of the acellular vaccines and their possible use in the United States.
The pertussis vaccines in current use in the United States are prepared from whole cells of a strain of Bordetella pertussis that is grown in broth medium, harvested by centrifugation, and killed or partially detoxified by heat or by the addition of a chemical agent, such as thimerosal, or by a combination of these methods. In contrast, the acellular vaccines developed in Japan and used in that country since 1981 contain one or more antigens derived from biologically active components of the B pertussis organism.1 An inactivated form of lymphocytosis promoting factor (LPF), also known as pertussis toxin and a variety of other synonyms, is a frequent component of acellular pertussis vaccines, as are filamentous hemagglutinins (FHA). Other constituents included in acellular vaccines are agglutinogens, a term denoting a variety of protein antigens on the surface of the B pertussis organism. Of the agglutinogens, a 69-kd outer membrane protein, when injected into neonatal mice, protects against B pertussis challenge.2 Acellular vaccines also have recently been derived from mutant pertussis toxin molecules prepared with recombinant DNA technology.3
The acellular vaccines produced in Japan have been classified into two types: B type, which contains LPF and FHA in roughly equal amounts; and T type, which contains mostly FHA but some LPF and agglutinogens.1,4
- Copyright © 1991 by the American Academy of Pediatrics