HOMEPRODUCTSCOMPANYCONTACTFAQResearchDictionaryPharmaSign Up FREE or Login

Case-control studies of the effectiveness of vaccines: validity and assessment of potential bias.

AbstractBACKGROUND:
Because case-control studies of the effectiveness of vaccines are nonexperimental, it is difficult to assure that bias does not affect the validity of the results.
METHODS:
A case-control study of the effectiveness of vaccines against Haemophilus influenzae type b (Hib) was replicated with a "sham" study. Cases were children > or =18 months of age with invasive infection caused by either Hib (original study) or Streptococcus pneumoniae (sham study) between January 1988 and December 1990. Controls were matched to the cases by both date and town of birth.
RESULTS:
Overall 34% of the 29 cases with invasive Hib infections and 64% of matched controls had received Hib vaccine. The effectiveness of Hib vaccines against infection with Hib was 88% (95% confidence interval, 57 to 97%; P < 0.01). In the sham study 74% of the 62 cases with invasive pneumococcal infections and 74% of matched controls had received Hib vaccine. The effectiveness of Hib vaccines against pneumococcal infection was 0% (P = 0.9).
CONCLUSION:
With the use of a virtually identical study design, vaccines against Hib were shown to be highly effective in preventing invasive Hib infections but were not effective in preventing invasive infections due to S. pneumoniae. Case-control studies are a valid method of assessing the effectiveness of vaccines.
AuthorsEugene D Shapiro
JournalThe Pediatric infectious disease journal (Pediatr Infect Dis J) Vol. 23 Issue 2 Pg. 127-31 (Feb 2004) ISSN: 0891-3668 [Print] United States
PMID14872178 (Publication Type: Comparative Study, Journal Article, Research Support, U.S. Gov't, P.H.S.)
Chemical References
  • Antibodies, Bacterial
  • Haemophilus Vaccines
  • Haemophilus influenzae type b polysaccharide vaccine
  • Polysaccharides, Bacterial
Topics
  • Antibodies, Bacterial (analysis)
  • Bacterial Capsules
  • Bias
  • Case-Control Studies
  • Child, Preschool
  • Confidence Intervals
  • Female
  • Haemophilus Infections (epidemiology, prevention & control)
  • Haemophilus Vaccines (administration & dosage)
  • Haemophilus influenzae type b (immunology)
  • Humans
  • Immunity (physiology)
  • Immunization Schedule
  • Infant
  • Male
  • Polysaccharides, Bacterial (administration & dosage)
  • Probability
  • Reference Values
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Treatment Outcome
  • Vaccination (methods)

Join CureHunter, for free Research Interface BASIC access!

Take advantage of free CureHunter research engine access to explore the best drug and treatment options for any disease. Find out why thousands of doctors, pharma researchers and patient activists around the world use CureHunter every day.
Realize the full power of the drug-disease research graph!


Choose Username:
Email:
Password:
Verify Password:
Enter Code Shown: