Adult pertussis in the pre- and post-vaccine eras: lifelong vaccine-induced immunity?

Abstract

In the pre-vaccine era, there was little information about clinical pertussis in adults, although deaths were noted. Today Bordetella pertussis infection in adults is noted to cause a full spectrum of clinical manifestations. If single serum serologic diagnosis becomes routine, the finding of adult cases would increase dramatically. Reported adult pertussis was rare in the pre-vaccine era and it has been increasing markedly in the present era. In the present vaccine era, data on adult pertussis and B. pertussis infection have been gathered by studying prolonged cough illnesses, serologic studies determining recent infections and prospective rate of illness studies. These studies suggest that approximately 15% of prolonged cough illnesses are due to B. pertussis infections; the yearly rate of infection is approximately 6% and the yearly rate of B. pertussis infection with clinical manifestations is >500/100,000. The duration of protection following natural infection or vaccination is relatively short. Therefore, unless new and better pertussis vaccines are developed, lifelong vaccine-induced immunity is not possible.

Keywords::

• adult
• Bordetella pertussis
• immunity
• pertussis
• vaccine

Financial & competing interests disclosure

The author has no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.

Key issues

• In the pre-vaccine era, clinical pertussis in adults was rarely reported. Nevertheless, it was recognized by the ‘pertussis experts’ of the time.

• Clinical pertussis in adults frequently has specific signature findings. These are: an afebrile paroxysmal cough illness which is worse at night; the cough is nonproductive and associated with posttussive apnea, vomiting and whoop; and there are often sweating episodes during non-coughing interludes.

• Laboratory confirmation of pertussis in adults is best done by PCR and single serum serologic study.

• Reported pertussis in adults was uncommon until relatively recently.

• Today Bordetella pertussis infection accounts for approximately 15% of prolonged afebrile cough illnesses in adults; infections (mostly asymptomatic) occur in about 6% of adults per year; and the rate of B. pertussis illness in adults is >500/100,000 per year.

• The duration of protection following infection on vaccination is relatively short. Contrary to popular belief, studies have shown that protection offered by DTwP vaccination may be better than immunity after natural infection in childhood.

• With our present DTaP and Tdap vaccines, lifelong vaccine-induced immunity is not possible.

• With our present vaccines, we should concentrate on preventing infection in young infants by immunizing pregnant women, cocooning around young infants and lowering the start date of immunization in infants.