Safety and immunogenicity on the formulation of trivalent split influenza vaccine among healthy people aged over 18 years

Abstract

To evaluate the safety and immunogenicity of split influenza vaccine (Anflu(®)). An open-labeled clinical trial was carried out in adults aged 18 - 60 years and elders aged over 60 years from August to September, 2010 in Shenyang, Liaoning province. One dose of split influenza vaccine was administered and adverse events were observed. Serum samples were obtained prior to vaccination and 21 days post vaccination. A/H1N1, A/H3N2 and B antibodies against influenza virus were measured using micro-hemagglutination inhibition (HI) assay. A total of 130 subjects were recruited and 120 paired serum samples were obtained. The overall rate of adverse events was 2.3% (3/130) and all of them with systemic reaction. No single serious adverse event was reported. 21 days after the vaccination, the sero-conversion rates of A/H1N1, A/H3N2 and B antibodies against influenza virus among adults were 82.5%, 93.7% and 92.1%, respectively. The Geometric Mean Titer (GMT) ratios were 20.2, 32.0 and 11.4, while the sero-protection rates were 92.1%, 98.4% and 98.4%, respectively. The sero-conversion rates of antibodies among elders were 89.5%, 91.2% and 87.7%, with the GMT ratios as 23.9, 39.8 and 15.1, respectively. The sero-protection rates were 93.0%, 94.7% and 96.5%, respectively. All indexes of A/H1N1, A/H3N2 and B antibodies exceeded the licensure criteria established by the EU Committee for Medicinal Products for Human Use, proving the trial vaccine Anflu(®) with good safety and immunogenicity.