Diphtheria, Tetanus, and Pertussis Immunizations in Adults

A ten year follow-up after immunization with a two component acellular pertussis vaccine

OBJECTIVES

To investigate the duration of antitoxin response and immunity to pertussis 10 years after priming with either two or three doses of a two component acellular pertussis vaccine or with three doses of a whole cell vaccine and then boostered with the acellular vaccine.

SUBJECTS

At 11 years of age 207 of 304 (68%) children of the original cohort returned for a blood sample and 262 (86%) participated by answering a questionnaire.

METHODS

Neutralizing antibodies to pertussis toxin (antitoxin) were analyzed by the Chinese hamster ovary cell assay. Clinical pertussis and pertussis exposure were investigated by a structured questionnaire.

RESULTS

Measurable antitoxin was found in 77% of the samples, with no differences by type of vaccine or by the number of doses given for priming. A significant decrease of antibody concentration (P<0.001) was noted from the previous recall at 4 years of age, and significant titer rises were found for 14% of the children, irrespective of known exposure. Confirmed pertussis during follow-up, as defined in the study, was reported for 14 of 262 (5%) children.

CONCLUSIONS

The study showed that antitoxin concentrations are maintained in a situation of endemic pertussis and indicated that the long term protection after an acellular booster was good, irrespective of type of vaccine or the number of doses of acellular vaccine given for priming.

The immunogenicity and safety of a new combined diphtheria, tetanus and poliomyelitis booster vaccine (Td-eIPV)

In view of the continuing risk of contracting tetanus, diphtheria and poliomyelitis, and the well-documented decline in immunity with time, the need for booster vaccinations is substantial. The immunogenicity and safety of a new combined booster vaccine against tetanus, diphtheria and poliomyelitis (REVAXIS) developed by Pasteur Mérieux Connaught (Lyon, France) were evaluated in four clinical studies. This vaccine (Td-eIPV) combines an adsorbed tetanus toxoid and low-dose diphtheria toxoid vaccine (Td) with an enhanced, inactivated polio vaccine against poliovirus types 1, 2 and 3 (eIPV). In 256 healthy young adults, a single dose of Td-eIPV was shown to be immunogenic, eliciting antibody levels considered protective against disease for each vaccine component in > or = 99.6% of the subjects. In 112 healthy older subjects (> 40 years of age), two doses of Td-eIPV elicited seroprotective levels of antibodies in 94% of the subjects for diphtheria, and in all subjects for tetanus and poliovirus types 1, 2 and 3. Safety data from all 368 subjects, as well as 31 phase I volunteers and 1,742 subjects included in a safety study, reveal that the vaccine is safe. Most reactions were predictable, temporary and mild. There was no evidence that the vaccine was associated with any clinically serious event or modification of clinical laboratory parameters. The data reviewed here show that Td-eIPV is immunogenic and safe when administered as a booster vaccination in healthy adults of all ages.

Pediatric immunizations

The record of disease prevention in children is an impressive testament to our universal immunization program. However, these successes are being threatened by rates of vaccination in some areas of the country that are substantially less than those seen in the developing world. Unless the pediatric immunization rates are improved, epidemics of other vaccine-preventable diseases will recur, as evidenced by the measles outbreaks. Although the tools needed for disease prevention are available, the means for their delivery are lacking. It is the obligation of us all to immunize the nation's children.