Protect the newborns from whooping

Natasha Lee, University of Cambridge School of Clinical Medicine, Addenbrooke’s Hospital, Hills Road, Cambridge, CB2 0SP

The Department of Health (DH) announced recently that pregnant women at 28-38 weeks gestation would be offered vaccination against pertussis, also known as whooping cough [1]. Pertussis might be something that we would only associate with developing countries, but maybe it is no longer so rare in the UK.
Data from the Health Protection Agency has shown that in England and Wales in 2012, there were a total of 4791 laboratory-confirmed cases which have exceeded the total number of cases (1118) in the whole of 2011 by more than four times [2]. The first eight months of 2012 also saw nine deaths in infants under four months, which is the highest ever since 1982.

Pertussis is caused by the Gram negative bacilli Bordetella pertussis. Infections are characterised by alternating paroxysms of cough and ‘whoop’ when air is forced in through a partially-closed glottis. Infants suffer from apnoeas due to the inability to ‘whoop’ and have a higher mortality rate due to severe infections and complications.

Under the current immunisation schedule, children are vaccinated against pertussis at 2, 3, 4 and 40 months of age. However, natural infections or immunisations do not provide lifelong protection [3], thus the bacteria continue to circulate when infected teenagers and adults develop milder cough as their immunity wanes. After the unfounded scare over the old whole cell pertussis vaccine in the 1970-80s vaccine uptake has recovered to a relatively good level of about 88-95% [4]. There is, however suggestion that the new acellular vaccine may be less potent than the old whole cell vaccine that cannot be explained by genetic changes in the bacterial antigens [5].

The acellular pertussis vaccine is not licensed for children under two months. Neonates do respond to the vaccine but the efficacies of other vaccines administered in combination are reduced [6]. The DH’s decision means that newborns will acquire passive immunity in utero with further boosting of immunity according to the normal vaccination schedule. The vaccine has good safety profile in children but there is limited data in pregnant women which will need monitoring [7].
It is possible that the rise in the number of cases is simply due to increased awareness, better reporting and improved detection techniques. Although this may seem like a minor glitch compared to the pre-vaccine era when the incidence was over 100 000 per year, perhaps one should not take this so lightly when the rise in disease is manifesting globally [8, 9]. It is therefore necessary to regularly review the vaccination programme, consider catch up immunisations and continue to educate the public about vaccines in general.

References: 

1. Department of Health. Pregnant women to be offered whooping cough vaccination London [updated 2012 Sep 28]; Available from: http://www.dh.gov.uk/health/2012/09/whooping-cough/.
2. Health Protection Agency. HPA welcomes introduction of whooping cough vaccination for pregnant women as outbreak continues [updated 2012 Sep 28]; Available from: http://www.hpa.org.uk/webw/HPAweb&HPAwebStandard/HPAweb_C/1317136292634.
3. Winter K, Harriman K, Zipprich J, Schechter R, Talarico J, Watt J, Chavez G. California Pertussis Epidemic, 2010. J Pediatr. 2012 Jul 20. doi:10.1016/j.jpeds.2012.05.041
4. COVER (Cover of Vaccination Evaluated Rapidly) programme. COVER data Q12-1 Apr-Jun 2012 (Excel Spreadsheet). Health Protection Agency; [updated 2012 Sep 28]; Available from: http://www.hpa.org.uk/webc/HPAwebFile/HPAweb_C/1317136302861.
5. Cherry JD. Why do pertussis vaccines fail? Pediatrics. 2012 May;129(5):968-70. doi:10.1542/peds.2011-2594
6. Knuf M, Schmitt HJ, Wolter J, Schuerman L, Jacquet JM, Kieninger D, Siegrist CA, Zepp F. Neonatal vaccination with an acellular pertussis vaccine accelerates the acquisition of pertussis antibodies in infants. J Pediatr. 2008 May;152(5):655-60, 60 e1. doi:10.1016/j.jpeds.2007.09.034
7. Billingsley M. Pregnant women in UK are offered whooping cough vaccine to protect newborns. BMJ. 2012;345. doi:10.1136/bmj.e6594
8. Centers for Disease Control and Prevention. Pertussis Epidemic - Washington, 2012. MMWR. 2012 Jul 20;61(28).
9. Department of Health. Ongoing pertussis epidemic in Western Australia. Disease WAtch [Internet]. 2012 Mar; 16(1): Available from: http://www.health.wa.gov.au/diseasewatch/vol16_issue1/all.cfm.

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