title: H7N9 live attenuated influenza vaccine in healthy adults: a randomised, double-blind, placebo-controlled, phase 1 trial.
abstract: BACKGROUND
  H7N9 avian influenza viruses characterised by high virulence and presence of mammalian adaptation markers have pandemic potential. Specific influenza vaccines remain the main defence. We assessed the safety and immunogenicity of an H7N9 live attenuated influenza vaccine (LAIV) candidate in healthy adult volunteers.
  
  
  METHODS
  We did a phase 1, double-blind, randomised, placebo-controlled trial in Saint Petersburg, Russia. Eligible participants were healthy adults aged 18-49 years. The participants were randomised 3:1 to receive live vaccine or placebo, according to a computer-generated randomisation scheme. Two doses of vaccine or placebo were administered intranasally 28 days apart, each followed by 7 day stays in hospital. Immune responses were assessed in nasal swabs, saliva, and serum specimens collected before and 28 days after each vaccine dose. The primary outcome was the safety profile. This trial is registered with ClinicalTrials.gov, number NCT02480101.
  
  
  RESULTS
  Between Oct 21, 2014, and Oct 31, 2014, 40 adults were randomised, of whom 39 (98%) were included in the per-protocol analysis (29 in the vaccine group and ten in the placebo group). The frequency of adverse events did not differ between the vaccine and placebo groups. Seroconversion of neutralising antibodies was seen in 14 participants after the first vaccine dose (48%, 95% CI 29·4-67·5) and 21 after the second vaccine dose (72%, 52·8-87·3). Immune responses were seen in 27 of 29 recipients (93%, 95% CI 77·2-99·2). Adverse effects were seen in 19 (63%) vaccine recipients and nine (90%) placebo recipients after the first dose and in nine (31%) and four (40%), respectively, after the second dose. These effects were mainly local and all were mild.
  
  
  CONCLUSIONS
  The H7N9 LAIV was well tolerated and safe and showed good immunogenicity.
  
  
  BACKGROUND
  WHO.
authors.affiliation: Department of Virology, Institute of Experimental Medicine, Saint Petersburg, Russia.
authors.forename: Larisa
authors.initials: L
authors.lastname: Rudenko
authors.affiliation: Department of Virology, Institute of Experimental Medicine, Saint Petersburg, Russia. Electronic address: isakova.sivak@gmail.com.
authors.forename: Irina
authors.initials: I
authors.lastname: Isakova-Sivak
authors.affiliation: Department of Virology, Institute of Experimental Medicine, Saint Petersburg, Russia.
authors.forename: Anatoly
authors.initials: A
authors.lastname: Naykhin
authors.affiliation: Department of Virology, Institute of Experimental Medicine, Saint Petersburg, Russia.
authors.forename: Irina
authors.initials: I
authors.lastname: Kiseleva
authors.affiliation: Department of Molecular Virology, Research Institute of Influenza, Saint Petersburg, Russia.
authors.forename: Marina
authors.initials: M
authors.lastname: Stukova
authors.affiliation: Department of Epidemiology and Prophylaxis, Research Institute of Influenza, Saint Petersburg, Russia.
authors.forename: Mariana
authors.initials: M
authors.lastname: Erofeeva
authors.affiliation: Department of Virology, Institute of Experimental Medicine, Saint Petersburg, Russia.
authors.forename: Daniil
authors.initials: D
authors.lastname: Korenkov
authors.affiliation: Department of Virology, Institute of Experimental Medicine, Saint Petersburg, Russia.
authors.forename: Victoria
authors.initials: V
authors.lastname: Matyushenko
authors.affiliation: Department of Essential Medicines and Health Products, World Health Organization, Geneva, Switzerland.
authors.forename: Erin
authors.initials: E
authors.lastname: Sparrow
authors.affiliation: Department of Health Systems and Innovation, World Health Organization, Geneva, Switzerland.
authors.forename: Marie-Paule
authors.initials: MP
authors.lastname: Kieny
mesh_terms: D000328:Adult; D000914:Antibodies, Viral / Q000096:biosynthesis / Q000097:blood; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007115:Immunization Schedule; D064766:Influenza A Virus, H7N9 Subtype / Q000276:immunology*; D007252:Influenza Vaccines; D007251:Influenza, Human / Q000517:prevention & control* / Q000821:virology; D008297:Male; D008875:Middle Aged; D014613:Vaccines, Attenuated; D055815:Young Adult
chemical_list: D000914:Antibodies, Viral; D007252:Influenza Vaccines; D014613:Vaccines, Attenuated