title: Clinical testing of pre-pandemic live attenuated A/H5N2 influenza candidate vaccine in adult volunteers: results from a placebo-controlled, randomized double-blind phase I study.
abstract: BACKGROUND
  This study describes a double-blinded randomized placebo-controlled phase I clinical trial of A/H5N2 live attenuated influenza vaccine in healthy volunteers.
  
  
  METHODS
  Two doses of vaccine or placebo were administered intranasally to 30 and 10 subjects, respectively. Nasal swabs were examined for vaccine shedding and local antibody responses; serum samples were tested for binding, hemagglutinating and neutralizing antibodies and peripheral blood mononuclear cells were tested for cell-mediated immune responses.
  
  
  RESULTS
  The vaccine was well tolerated and not associated with increased rates of adverse events or the occurrence of serious adverse events. Influenza virus was detected in nasal swabs on the first day in the majority of volunteers (93%), while 17% of volunteers tested positive on the second, none on the third day or later following the first vaccination; lower frequency of shedding was observed after the second vaccination. The vaccine was immunogenic as assessed four weeks after the second dose, with 37.9% and 48.3% of subjects seroconverting by hemagglutination inhibition and neutralization assays, respectively. An immune response was observed in 96.6% subjects that received A/H5N2 LAIV in at least one of the assays conducted. None of the placebo recipients exhibited a response in any of the assays.
  
  
  CONCLUSIONS
  The A/H5N2 vaccine was safe, well tolerated, and immunogenic in healthy adults.
  
  
  BACKGROUND
  ClinicalTrials.gov NCT01719783.
authors: Department of Virology, Institute of Experimental Medicine, 197376 St Petersburg, Russia.
authors: Larisa
authors: L
authors: Rudenko
authors: Department of Virology, Institute of Experimental Medicine, 197376 St Petersburg, Russia. Electronic address: irina.v.kiseleva@mail.ru.
authors: Irina
authors: I
authors: Kiseleva
authors: Department of Molecular Virology, Institute of Influenza, 197376 St Petersburg, Russia.
authors: Marina
authors: M
authors: Stukova
authors: Department of Epidemiology and Prophylaxis, Institute of Influenza, 197376 St Petersburg, Russia.
authors: Marianna
authors: M
authors: Erofeeva
authors: Department of Virology, Institute of Experimental Medicine, 197376 St Petersburg, Russia.
authors: Anatoly
authors: A
authors: Naykhin
authors: Department of Virology, Institute of Experimental Medicine, 197376 St Petersburg, Russia.
authors: Svetlana
authors: S
authors: Donina
authors: Department of Virology, Institute of Experimental Medicine, 197376 St Petersburg, Russia.
authors: Natalie
authors: N
authors: Larionova
authors: Department of Molecular Virology, Institute of Influenza, 197376 St Petersburg, Russia.
authors: Maria
authors: M
authors: Pisareva
authors: Department of Biotechnology, Institute of Influenza, 197376 St Petersburg, Russia.
authors: Vera
authors: V
authors: Krivitskaya
authors: PATH, Seattle, WA 98121, USA.
authors: Jorge
authors: J
authors: Flores
mesh_terms: D000281:Administration, Intranasal; D000293:Adolescent; D000328:Adult; D057134:Antibodies, Neutralizing / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood; D004311:Double-Blind Method; D064420:Drug-Related Side Effects and Adverse Reactions / Q000453:epidemiology / Q000473:pathology; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D053125:Influenza A Virus, H5N2 Subtype / Q000276:immunology*; D007252:Influenza Vaccines / Q000008:administration & dosage* / Q000009:adverse effects / Q000276:immunology*; D007251:Influenza, Human / Q000517:prevention & control* / Q000821:virology; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008297:Male; D008875:Middle Aged; D010919:Placebos / Q000008:administration & dosage; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology; D055815:Young Adult
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D007252:Influenza Vaccines; D010919:Placebos; D014613:Vaccines, Attenuated
keywords: A/H5N2; Clinical trial; Immune response; Influenza; Live attenuated influenza vaccine; Pre-pandemic vaccine