Improving protection against pertussis requires sorting the facts from the artefacts
Pertussis is a disease of significant morbidity and, in infants, mortality. Regrettably, even though there is greater than 20-fold reduction in pertussis burden with immunisation,1 it persists globally as a significant public health problem. For more than two decades, Australia has had the highest reported rates of pertussis in the world.2 In the 1990s, this was driven by the introduction of mandatory reporting by laboratories of positive test results for vaccine-preventable diseases to the National Notifiable Diseases Surveillance System and extensive use of serological tests for diagnosis, primarily in adults.3 Unlike many other countries, all positive test results in Australia are included in national data. Also, testing for pertussis by polymerase chain reaction (PCR) has qualified for reimbursement since 2008, after which a sevenfold increase in testing of children in general practice was documented.4 Pertussis epidemics occurred sequentially across Australia from 2008 to 2012 and, unlike previous epidemics, the highest notification rates were for children under 10 years of age. This raises the question of whether Australia’s “pertussis problem” is related to vaccines with poor effectiveness or is an artefact of testing.
- 1. Cherry JD. Epidemic pertussis in 2012 — the resurgence of a vaccine-preventable disease. N Engl J Med 2012; 367: 785-787.
- 2. McIntyre PB. Is Australia the world capital of pertussis? National Pertussis Workshop; 2011 Aug 25–26; Sydney, Australia. http://ncirs.edu.au/news/past-news-events/Day%201/McIntyre-Is-Australia-world-capital-PertussisWS-25_26Aug11.pdf (accessed Feb 2014).
- 3. Quinn HE, McIntyre PB. Pertussis epidemiology in Australia over the decade 1995–2005 — trends by region and age group. Commun Dis Intell Q Rep 2007; 31: 205-215.
- 4. Kaczmarek MC, Valenti L, Kelly HA, et al. Sevenfold increase in likelihood of pertussis test requests in a stable set of Australian general practice encounters, 2000–2011. Med J Aust 2013; 198: 624-628. <MJA full text>
- 5. Farrington CP. Estimation of vaccine effectiveness using the screening method. Int J Epidemiol 1993; 22: 742-746.
- 6. Sheridan SL, McCall BJ, Davis CA, et al. Acellular pertussis vaccine effectiveness for children during the 2009–2010 pertussis epidemic in Queensland. Med J Aust 2014; 200: 334-338. <MJA full text>
- 7. Klein NP, Bartlett J, Rowhani-Rahbar A, et al. Waning protection after fifth dose of acellular pertussis vaccine in children. N Engl J Med 2012; 367: 1012-1019.
- 8. Misegades LK, Winter K, Harriman K, et al. Association of childhood pertussis with receipt of 5 doses of pertussis vaccine by time since last vaccine dose, California, 2010. JAMA 2012; 308: 2126-2132.
- 9. Sheridan SL, Ware RS, Grimwood K, Lambert SB. Number and order of whole cell pertussis vaccines in infancy and disease protection. JAMA 2012; 308: 454-456.
- 10. Quinn HE, Snelling TL, Macartney KK, McIntyre PB. Duration of protection after first dose of acellular pertussis vaccine in infants. Pediatrics 2014; 133: e513-e519.
- 11. McCallum LK, Liu B, McIntyre P, Jorm LR. Estimating the burden of pertussis in young children on hospitals and emergency departments: a study using linked routinely collected data. Epidemiol Infect 2014; 142: 695-705.
- 12. Hethcote HW, Horby P, McIntyre P. Using computer simulations to compare pertussis vaccination strategies in Australia. Vaccine 2004; 22: 2181-2191.
- 13. Salmaso S, Mastrantonio P, Tozzi AE, et al. Sustained efficacy during the first 6 years of life of 3-component acellular pertussis vaccines administered in infancy: the Italian experience. Pediatrics 2001; 108: E81.
- 14. Campbell P, McIntyre P, Quinn H, et al. Increased population prevalence of low pertussis toxin antibody levels in young children preceding a record pertussis epidemic in Australia. PLOS ONE 2012; 7: e35874.
- 15. Thorstensson R, Trollfors B, Al-Tawil N, et al. A phase I clinical study of a live attenuated Bordetella pertussis vaccine — BPZE1; a single centre, double-blind, placebo-controlled, dose-escalating study of BPZE1 given intranasally to healthy adult male volunteers. PLOS ONE 2014; 9: e83449.
- 16. Australian Government Department of Health. National Immunisation Strategy 2013–2018. Canberra: DOH, 2013. http://www.immunise.health. gov.au/internet/immunise/publishing.nsf/Content/A894B6DF512D815DCA 257BA300053819/$File/nat-immune-strategy-2013-18-final.pdf (accessed Mar 2014).
Publication of your online response is subject to the Medical Journal of Australia's editorial discretion. You will be notified by email within five working days should your response be accepted.