title: Immune interference in the setting of same-day administration of two similar inactivated alphavirus vaccines: eastern equine and western equine encephalitis.
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.
authors.affiliation: United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, MD 21702-5011, United States. Ronald.Reisler@hhs.gov
authors.forename: Ronald B
authors.initials: RB
authors.lastname: Reisler
authors.forename: Paul H
authors.initials: PH
authors.lastname: Gibbs
authors.forename: Denise K
authors.initials: DK
authors.lastname: Danner
authors.forename: Ellen F
authors.initials: EF
authors.lastname: Boudreau
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000524:Alphavirus / Q000235:genetics / Q000276:immunology; D057134:Antibodies, Neutralizing / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood; D004337:Drug Carriers / Q000008:administration & dosage*; D004347:Drug Interactions; D004663:Encephalitis Virus, Eastern Equine / Q000235:genetics / Q000276:immunology*; D004667:Encephalitis Virus, Western Equine / Q000235:genetics / Q000276:immunology*; D020242:Encephalomyelitis, Eastern Equine / Q000517:prevention & control; D020241:Encephalomyelitis, Western Equine / Q000517:prevention & control; D005260:Female; D005822:Genetic Vectors; D006801:Humans; D008297:Male; D008875:Middle Aged; D013997:Time Factors; D014611:Vaccination / Q000379:methods*; D010948:Viral Plaque Assay; D014765:Viral Vaccines / Q000008:administration & dosage*; D055815:Young Adult
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D004337:Drug Carriers; D014765:Viral Vaccines