Immune interference in the setting of same-day administration of two similar inactivated alphavirus vaccines: eastern equine and western equine encephalitis

Vaccine. 2012 Nov 26;30(50):7271-7. doi: 10.1016/j.vaccine.2012.09.049. Epub 2012 Sep 29.

Abstract

We compared the effect on primary vaccination plaque-reduction neutralization 80% titers (PRNT80) responses of same-day administration (at different injection sites) of two similar investigational inactivated alphavirus vaccines, eastern equine encephalitis (EEE) vaccine (TSI-GSD 104) and western equine encephalitis (WEE) vaccine (TSI-GSD 210) to separate administration. Overall, primary response rate for EEE vaccine was 524/796 (66%) and overall primary response rate for WEE vaccine was 291/695 (42%). EEE vaccine same-day administration yielded a 59% response rate and a responder geometric mean titer (GMT)=89 while separate administration yielded a response rate of 69% and a responder GMT=119. WEE vaccine same-day administration yielded a 30% response rate and a responder GMT=53 while separate administration yielded a response rate of 54% and a responder GMT=79. EEE response rates for same-day administration (group A) vs. non-same-day administration (group B) were significantly affected by gender. A logistic regression model predicting response to EEE comparing group B to group A for females yielded an OR=4.10 (95% CL 1.97-8.55; p=.0002) and for males yielded an OR=1.25 (95% CL 0.76-2.07; p=.3768). WEE response rates for same-day administration vs. non-same-day administration were independent of gender. A logistic regression model predicting response to WEE comparing group B to group A yielded an OR=2.14 (95% CL 1.22-3.73; p=.0077). We report immune interference occurring with same-day administration of two completely separate formalin inactivated viral vaccines in humans. These findings combined with the findings of others regarding immune interference would argue for a renewed emphasis on studying the immunological mechanisms of induction of inactivated viral vaccine protection.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Alphavirus / genetics
  • Alphavirus / immunology
  • Antibodies, Neutralizing / blood
  • Antibodies, Viral / blood
  • Drug Carriers / administration & dosage*
  • Drug Interactions*
  • Encephalitis Virus, Eastern Equine / genetics
  • Encephalitis Virus, Eastern Equine / immunology*
  • Encephalitis Virus, Western Equine / genetics
  • Encephalitis Virus, Western Equine / immunology*
  • Encephalomyelitis, Eastern Equine / prevention & control
  • Encephalomyelitis, Western Equine / prevention & control
  • Female
  • Genetic Vectors
  • Humans
  • Male
  • Middle Aged
  • Time Factors
  • Vaccination / methods*
  • Viral Plaque Assay
  • Viral Vaccines / administration & dosage*
  • Young Adult

Substances

  • Antibodies, Neutralizing
  • Antibodies, Viral
  • Drug Carriers
  • Viral Vaccines