Pertussis in adolescents and adults: should we vaccinate?
BACKGROUND
The incidence of reported pertussis among adolescents, adults, and young infants has increased sharply over the past decade. Combined acellular pertussis vaccines for adolescents and adults are available in Canada, Australia, and Germany and may soon be considered for use in the United States.


OBJECTIVE
To evaluate the potential health benefits, risks, and costs of a national pertussis vaccination program for adolescents and/or adults.


METHODS
The projected health states and immunity levels associated with pertussis disease and vaccination were simulated with a Markov model. The following strategies were examined from the health care payer and societal perspectives: (1) no vaccination; (2) 1-time adolescent vaccination; (3) 1-time adult vaccination; (4) adult vaccination with boosters; (5) adolescent and adult vaccination with boosters; and (6) postpartum vaccination. Data on disease incidence, costs, outcomes, vaccine efficacy, and adverse events were based on published studies, recent unpublished clinical trials, and expert panel input.


METHODS
Cases prevented, adverse events, costs (in 2004 US dollars), cost per case prevented, and cost per quality-adjusted life-year (QALY) saved.


RESULTS
One-time adolescent vaccination would prevent 30800 cases of pertussis (36% of projected cases) and would result in 91000 vaccine adverse events (67% local reactions). If pertussis vaccination cost $15 and vaccine coverage was 76%, then 1-time adolescent vaccination would cost $1100 per case prevented (or $1200 per case prevented) or $20000 per QALY (or $23000 per QALY) saved, from the societal (or health care payer) perspective. With a threshold of $50000 per QALY saved, the adolescent and adult vaccination with boosters strategy became potentially cost-effective from the societal perspective only if 2 conditions were met simultaneously, ie, (1) the disease incidence for adolescents and adults was > or =6 times higher than base-case assumptions and (2) the cost of vaccination was less than $10. Adult vaccination strategies were more costly and less effective than adolescent vaccination strategies. The results were sensitive to assumptions about disease incidence, vaccine efficacy, frequency of vaccine adverse events, and vaccine costs.


CONCLUSIONS
Routine pertussis vaccination of adolescents results in net health benefits and may be relatively cost-effective.
Lee
Grace M
GM
Center for Child Health Care Studies, Department of Ambulatory Care and Prevention, Harvard Pilgrim Health Care and Harvard Medical School, Boston, Massachusetts 02215, USA. grace_lee@hphc.org
Lebaron
Charles
C
Murphy
Trudy V
TV
Lett
Susan
S
Schauer
Stephanie
S
Lieu
Tracy A
TA
D000293:Adolescent; D000328:Adult; D003198:Computer Simulation; D017281:Cost of Illness; D003362:Cost-Benefit Analysis; D003365:Costs and Cost Analysis; D003661:Decision Support Techniques; D022422:Diphtheria-Tetanus Vaccine / Q000008:administration & dosage* / Q000009:adverse effects / Q000191:economics; D015721:Diphtheria-Tetanus-Pertussis Vaccine / Q000008:administration & dosage / Q000009:adverse effects / Q000191:economics; D022681:Diphtheria-Tetanus-acellular Pertussis Vaccines / Q000008:administration & dosage* / Q000009:adverse effects / Q000191:economics; D004198:Disease Susceptibility; D018562:Disease Transmission, Infectious; D005260:Female; D006801:Humans; D007115:Immunization Schedule; D007117:Immunization, Secondary; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008390:Markov Chains; D008962:Models, Theoretical; D049590:Postpartum Period; D011247:Pregnancy; D019057:Quality-Adjusted Life Years; D014481:United States / Q000453:epidemiology; D014917:Whooping Cough / Q000150:complications / Q000191:economics / Q000453:epidemiology / Q000517:prevention & control*
D022422:Diphtheria-Tetanus Vaccine; D015721:Diphtheria-Tetanus-Pertussis Vaccine; D022681:Diphtheria-Tetanus-acellular Pertussis Vaccines