Vaccine
http://www.sciencedirect.com/science/journal/0264410X
Volume 28, Issue 38 pp. 6123-6402 (31 August 2010)

Methodology and measurement of the effectiveness of Haemophilus influenzae type b vaccine: Systematic review Review Article
Pages 6128-6136
Rosalyn E. O’Loughlin, Karen Edmond, Punam Mangtani, Adam L. Cohen, Sharmila Shetty, Rana Hajjeh, Kim Mulholland

Abstract
The use of the highly effective Haemophilus influenzae type b (Hib) conjugate vaccine has increased globally. We review the benefits and limitations of studies measuring Hib vaccine effectiveness (VE). We critically examine the case–control approach by assessing the similarities and differences in methodology and findings and discuss the need for future Hib VE studies. In the absence of good surveillance data, vaccine effectiveness studies can play an important role, particularly with the increasing use of pneumococcal vaccine that has not been well tested under field conditions in less developed countries. However, the effectiveness of Hib vaccine has been well documented so the need for future VE Hib studies is minimal.