Acellular pertussis vaccine

Diphtheria and tetanus toxoids and acellular pertussis vaccine (DTaP). The... 

In the 1940s, diphtheria toxoid was combined with tetanus toxoid and whole cell pertussis vaccines, and later with the acellular pertussis vaccine. The diphtheria toxoid, tetanus toxoid, and acellular pertussis vaccine are part of the routine childhood immunization schedule. Diphtheria toxoid is also combined with tetanus toxoid and is commonly used as a booster vaccine. The pediatric product (DT) has a higher amount of diphtheria toxoid than does the adult product (Td). Diphtheria toxoid is not available as an individual vaccine. 

The first pertussis whole cell vaccine was a mixture of killed organisms that was associated with frequent local and systemic reactions. In the late 1980s, an acellular pertussis vaccine was introduced that contains purified pertussis components that are immunogenic but associated with fewer adverse reactions. Acellular pertussis vaccine is available in combination with tetanus and diphtheria toxoids. Pertussis is not available as a separate vaccine component. In the spring of 2005, the Food and Drug Administration (FDA) approved tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccines for use in adolescents and adults. 

Tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine (Tdap) is recommended as a single booster for the following groups in place of a tetanus booster. 

The whole cell pertussis vaccine has been highly associated with temperature elevations however, the prevalence has significantly decreased since the introduction of the acellular pertussis vaccine. Live virus vaccines are also associated with fever. 

Acellular pertussis vaccine is usually administered in combination with diphtheria and tetanus toxoids (as DTaP). 

Acel-Imune Diphtheria, tetanus toxoids acellular pertussis vaccine Jan. 6, 1992 Takeda Chemical Industries /American Cyanamid... 

Olin, P., Rasmussen, F., Gustafsson, L., Hallander, H.O., and Heijbel, H. (1997) Randomised controlled trial of two-component, three-component, and five-component acellular pertussis vaccines compared with whole-cell pertussis vaccine. Ad Hoc Group for the Study of Pertussis Vaccines. Lancet. 350, 1569-1577. 

To some extent the simplest vaccines are those in which the bacterial or viral pathogens has been killed by chemicals or heat so that they themselves cannot cause disease but can confer protection against invasion. This has been used, for example, for the combined diphtheria-tetanus-pertussis vaccine. In this case there were concerns about the presence of entire cells that could cause complications other than the needed protection. Recently acellular systems have been introduced which may... 

Nakayama, T., Aizawa, C., and Kuno-Sakai, H. 1999. A clinical analysis of gelatine allergy and determination of its causal relationship to the previous administration of gelatin-containing acellular pertussis vaccine combined with diphtheria and tetanus toxoids. J Allergy Clin Immunol 103(2) 321—325. 

The pertussis vaccine consists either of whole, killed bacteria, or selected subunits of the bacteria. Until 1991, only the whole cell vaccine was available. In 1991, FDA (Center for Biological Evaluation and Research) licensed the first vaccine that contained pertussis subunits (referred to as acellular pertussis) for use in the last two doses of the five-dose series. In 1996, an acellular vaccine was licensed for use in the first three doses. It is expected that acellular vaccine will be licensed for all five doses in the near future. 

The U.S. standard pertussis vaccine is used to standardize the potency of the whole cell pertussis vaccine. The number of protective units in the vaccine is estimated for each lot from the results of simultaneous intracerebral mouse-protection tests of the vaccine being studied and the U.S. reference standard (14,17). The potency of the acellular vaccines is estimated by their ability to produce antibodies to the proteins in the vaccine in a mouse model. These vaccines also undergo a series of animal safety tests to ensure that the inactivation and toxoiding steps were carried out correcdy (14,17). 

Matheson AJ, Goa KL. Diphtheria-tetanus-acellular pertussis vaccine adsorbed (Triacelluvax DTaP3-CB) a review of its use in the prevention of Bordetella pertussis infection. Paediatr Drugs 2000 2(2) 139-59. 

Whole-cell and acellular pertussis vaccines have been reviewed, with emphasis on the protectivity of the various virulence factors and antigens (1). The authors summarized their review as follows although Bordetella pertussis has at least five proteins required for virulence and an additional two toxic components, only serum neutralizing antibodies to pertussis toxin have been shown to confer immunity to pertussis. 

Quality control of acellular pertussis vaccines presents particular problems related to the various methods used for preparation of the active components, the different compositions of the final formulations, and different amounts of antigen. Researchers in the National Institute for Biological Standards and Control in the UK have presented a strategy capable of addressing the key problem areas likely to be encountered with all existing types of acellular pertussis vaccines and combinations (2). Their proposal could be considered as a starting point for improvement of quality control programs for these vaccines. 

An overview of clinical trials with a special diphtheria and tetanus toxoids and acellular pertussis (DTaP) vaccine has been published (3). The vaccine contains as pertussis components purified filamentous hemagglutinin, pertactin, and genetically engineered pertussis toxin. The vaccine induces high and long-lasting immunity and is at least as efficacious as most whole-cell pertussis vaccines and similar in efficacy to the most efficacious acellular... 

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