Decreasing childhood pertussis infection through vaccination of the elderly

Pertussis presenting as hoarseness in an adult

Pertussis is a rare condition in adults. This report describes a 65-year-old man presenting to the otolaryngology service with hoarseness secondary to pertussis. He had a history of worsening cough and hoarseness occurring over several weeks. Laryngoscopy showed significant erythema at the medial edges of the vocal folds. Stroboscopy demonstrated bilateral decreased amplitude and decreased mucosal wave of the vocal folds. Polymerase chain reaction testing of the sputum revealed Bordetella pertussis. The patient was started on azithromycin, and he reported gradual resolution of the chest and laryngeal symptoms over the next few months. Pertussis, or whooping cough, is not common in the United States because of childhood vaccination protocols. Nevertheless, otolaryngologists need to be aware of this condition as a possible cause of hoarseness.

[Pertussis vaccination for parents: proposal and evaluation of two professional practices in a maternity hospital]

BACKGROUND

Despite good rates of immunization among children, an apparent increase in the incidence of pertussis disease in infants in France has been observed, mainly because of low vaccination coverage among adults. Guidelines drawn up in 2004 recommend a vaccination strategy called cocooning for parents, but those guidelines are rarely followed by the medical community. Raising the vaccination rate among parents to 65% and the extension of pertussis vaccine booster for people between 26 and 28 years old could help control the disease.

OBJECTIVE AND METHODS

In a primary healthcare setting in 2009, we studied 2 groups of 188 and 190 parents of newborns in a maternity unit. We proposed 2 strategies: information and vaccine prescription for both parents (if eligible) at the time of discharge from the maternity unit (group 1) or vaccination proposed to both parents during hospitalization in the maternity unit (group 2). After 6 weeks, the vaccination rates of both groups were compared.

RESULTS

Analysis shows that parents had insufficient knowledge of the disease. Parents were often unaware of their vaccination status. Hence, objective data concerning the vaccination status was quickly available for only 42% of the population, making determination of eligibility unreliable. Only 8% of the parents were up to date for pertussis vaccination in the last 10 years, whereas 90% of the parents had the opportunity for vaccination and 37% of them had been eligible before the pregnancy. At the end of the study, 53% of the parents in group 1 were vaccinated, showing the positive impact of the medical encounter and vaccine prescription. During the study, 40% of the parents in group 2 who were proposed immediate vaccination in the maternity unit accepted it. This increased to 43% of group 2 parents being immunized by the time they had left the maternity unit. Proposing the vaccination at the maternity hospital was the more effective of the 2 strategies (P=0.03): at the end of the study, the objective was nearly reached with 64% of the parents being vaccinated.

CONCLUSIONS

The promotion of parental vaccination by the pediatrician in the maternity ward is simple and effective. Medical encounters resulting from prescriptions made during hospitalization could raise awareness in general practitioners and enable them to identify eligible adults for pertussis vaccination and vaccinate themselves. There is a need to discuss the complementarity and interactions between perinatal teams and general practitioners within the community healthcare network.

Oligosaccharide conjugates of Bordetella pertussis and bronchiseptica induce bactericidal antibodies, an addition to pertussis vaccine

Pertussis is a highly contagious respiratory disease that is especially dangerous for infants and children. Despite mass vaccination, reported pertussis cases have increased in the United States and other parts of the world, probably because of increased awareness, improved diagnostic means, and waning vaccine-induced immunity among adolescents and adults. Licensed vaccines do not kill the organism directly; the addition of a component inducing bactericidal antibodies would improve vaccine efficacy. We investigated Bordetella pertussis and Bordetella bronchiseptica LPS-derived core oligosaccharide (OS) protein conjugates for their immunogenicity in mice. B. pertussis and B. bronchiseptica core OS were bound to aminooxylated BSA via their terminal Kdo residues. The two conjugates induced similar anti-B. pertussis LPS IgG levels in mice. B. bronchiseptica was investigated because it is easier to grow than B. pertussis. Using B. bronchiseptica genetically modified strains deficient in the O-specific polysaccharide, we isolated fractions of core OS with one to five repeats of the terminal trisaccharide, having at the nonreducing end a GlcNAc or GalNAc, and bound them to BSA at different densities. The highest antibody levels in mice were elicited by conjugates containing an average of 8-17 OS chains per protein and with one repeat of the terminal trisaccharide. Conjugate-induced antisera were bactericidal against B. pertussis, and the titers correlated with ELISA-measured antibody levels (r = 0.74). Such conjugates are easy to prepare and standardize; added to a recombinant pertussis toxoid, they may induce antibacterial and antitoxin immunity.