RxPRODUCT NEWS: PROFILE: Boostrix (diphtheria-tetanus-acellular pertussis vaccine)

JULY 01, 2005
Monica Holmberg, PharmD

Boostrix—a booster vaccine combining Tetanus Toxoid, Reduced Diphtheria Toxoid, and Acellular Pertussis, Adsorbed—has received FDA approval for use in children and adolescents 10 to 18 years old. Boostrix, produced by GlaxoSmithKline, is the first pertussis vaccine in the United States for children >7 years old.1

Most people are vaccinated during childhood from diphtheria, tetanus, and pertussis with a combination vaccine (DTaP). The DTaP vaccination series is completed around age 5.2,3 Although regular boosters of tetanus and diphtheria are required and available as a combination vaccine (Td), additional vaccination for pertussis has not been available. Immunity begins to fade 5 to 10 years after immunization, leaving the adolescent population especially susceptible to pertussis infections.1

Adolescents with pertussis, often undiagnosed due to its less-symptomatic presentation, often act as a host to the disease. Bordetella pertussis, the organism responsible for the disease, is highly contagious and easily transmitted through airborne droplets in sneezes or coughs. In infants, who have not yet developed the immune system to ward off such infections, pertussis can be deadly.1

Pertussis, also known as "whooping cough,"typically presents similarly to the common cold; patients may complain of mild fever, runny nose, and coughing. As the disease progresses, the cough usually becomes severe and exhibits as a classic high-pitched "whooping"sound. Adolescent patients, however, generally do not develop the "whooping"noise associated with pertussis.1

Diphtheria usually presents as malaise, sore throat, and low-grade fever. Later in the disease, a membrane may form over the airway, creating respiratory obstruction. Five percent to 10% of individuals infected with diphtheria die from the disease; this rate rises to up to 20% in patients <5 and >40 years old.

Tetanus is caused by bacteria typically found in soil and manure. Initial symptoms include lockjaw, neck and abdomen stiffness, and difficulty swallowing. Later symptoms include fever, elevated blood pressure, and severe muscle spasms.

Clinical Trials

A US phase 3 clinical trial of Boostrix involving ~3000 patients aged 10 to 18 years demonstrated Boostrix to be of comparable safety and efficacy to an already-approved Td [Tetanus and Diphtheria Toxoids for Adult Use] vaccine. Antipertussis antibodies in the Boostrix patients were found to be noninferior to levels in infants vaccinated with the standard DTaP vaccine.1

An observer-blinded, randomized, controlled, multicenter clinical trial of 4114 patients aged 10 to 18 years compared vaccination with either 1 dose of Boostrix or an adult Td vaccine. Serology reports established that both groups obtained antidiphtheria and antitetanus levels that indicated immunity. The Boostrix group, however, demonstrated antipertussis levels similar to those in vaccinated infants with established pertussis immunity.1

Warnings, Precautions, and Adverse Events

Use as a primary vaccination has not yet been established. Boostrix should not be given to anyone with a history of hypersensitivity to any vaccine containing tetanus toxoid, diphtheria toxoid, or pertussis. Encephalopathy, progressive neurologic disorder, and uncontrolled epilepsy are contraindications for the administration of Boostrix. Additional caution should be used in patients experiencing fever >105ºF, collapse, shock, or inconsolable crying within 48 hours of administration or seizures within 3 days of administration.4

Pain, redness, and swelling at the site of injection were the most common local reactions to Boostrix. Systemic adverse effects included headache and fatigue.4

Dosage and Administration

Boostrix should be administered to the deltoid muscle as a 0.5-mL intramuscular injection. It never should be administered intravenously or subcutaneously.

Dr. Holmberg is a pharmacist with Phoenix Children's Hospital, Phoenix, Ariz.

For a list of references, send a stamped, self-addressed envelope to: References Department, Attn. A. Stahl, Pharmacy Times, 241 Forsgate Drive, Jamesburg, NJ 08831; or send an e-mail request to: astahl@ascendmedia.com.