Clinical Infectious Diseases (CID) – November 1, 2014

Clinical Infectious Diseases (CID)
Volume 59 Issue 9 November 1, 2014

Editorial Commentary: Fifteen Years of Protection by Meningococcal C Conjugate Vaccines: Lessons From Disease Surveillance
Martin C. J. Maiden and Jenny M. MacLennan
Author Affiliations
Department of Zoology, University of Oxford, United Kingdom
(See the Major Articles by Sadarangani et al on pages 1208–15, and Bijlsma et al on pages 1216–21.)
Despite the extensive advances that have been made in biomedical sciences in the past few decades, the development and implementation of novel vaccines remains a highly pragmatic and uncertain endeavor. Although the concept of vaccination is >200 years old and was formalized by Pasteur >100 years ago, progress in the development of vaccines remains comparatively slow and has not accelerated in the way seen in virtually all other areas of technology. The many reasons for this include safety concerns arising from the administration of vaccinations to otherwise healthy individuals, often infants or children, and our inability to predict reliably the behavior of a novel human vaccine at the population level from data gathered in laboratory experiments or even during phase I or phase II trials of human subjects [1]. Although large placebo-controlled double-blind phase III trials can provide useful information in both regards, these are very expensive, prohibitively so if the disease is rare, and even very large studies may be insufficiently powered to detect population effects [1].

It is often the case, therefore, that vaccines are introduced without full knowledge of their likely impact, particularly without knowledge of how population effects might be best exploited in vaccination schedules. Consequently, it is important to ensure that enhanced disease surveillance is in place before, during, and after any vaccine introduction to evaluate vaccine impact post hoc and enable immunization schedules to be modified as necessary. Two articles in this issue [2, 3], describing the effectiveness of meningococcal serogroup C conjugate (MCC) vaccines during a 15-year period in the Netherlands and Canada, demonstrate the lasting value of such surveillance data in understanding how a vaccine

The Impact of the Meningococcal Serogroup C Conjugate Vaccine in Canada Between 2002 and 2012
Clin Infect Dis. (2014) 59 (9): 1208-1215 doi:10.1093/cid/ciu597
Manish Sadarangani, David W. Scheifele, Scott A. Halperin, Wendy Vaudry, Nicole Le Saux,
Raymond Tsang, and Julie A. Bettinger
For the investigators of the Canadian Immunization Monitoring Program, ACTive (IMPACT)
The meningococcal serogroup C conjugate vaccine has significantly reduced serogroup C meningococcal disease in Canada, despite different immunization schedules used in different provinces. Direct and indirect protection was achieved with the largest reduction in the 15–24 year age group.

A Decade of Herd Protection After Introduction of Meningococcal Serogroup C Conjugate Vaccination
Clin Infect Dis. (2014) 59 (9): 1216-1221 doi:10.1093/cid/ciu601
Merijn W. Bijlsma, Matthijs C. Brouwer, Lodewijk Spanjaard, Diederik van de Beek, and Arie van der Ende
Nationwide laboratory surveillance data from the Netherlands (1998–2012) shows a decline of >93% in meningococcal serogroup C (MenC) invasive disease. Herd protection is responsible for >36% of MenC conjugate vaccine impact and lasts for ≥10 years.

Rotavirus Vaccines in Routine Use
Clin Infect Dis. (2014) 59 (9): 1291-1301 doi:10.1093/cid/ciu564
Jacqueline E. Tate and Umesh D. Parashar
Rotavirus vaccines have had substantial impact on diarrhea and rotavirus hospitalizations and on diarrhea mortality in children. The risk-benefit analysis of rotavirus vaccine is extremely favorable, but other strategies to improve vaccine effectiveness, particularly in low-income settings, should be considered.