Low response in eliciting neuraminidase inhibition activity of sera among recipients of a split, monovalent pandemic influenza vaccine during the 2009 pandemic

• Published in: PLOS ONE Vol. 15; no. 5; p. e0233001
• Main Authors: Ito, Hiroko, Nishimura, Hidekazu, Kisu, Tomoko, Hagiwara, Haruhisa, Watanabe, Oshi, Kadji, Francois Marie Ngako, Sato, Ko, Omiya, Suguru, Takashita, Emi, Nobusawa, Eri
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science (PLoS) 13.05.2020; Public Library of Science
• Subjects: Acids; Adolescent; Adult; Antibodies; Antibodies, Neutralizing; Antibodies, Viral; Antibody response; Antigens; Biology and Life Sciences; Child; Child, Preschool; Control; Diagnosis; Disease transmission; Epidemics; Exo-a-sialidase; Female; Hemagglutinins; History, 21st Century; Hospitals; Host-virus relationships; Humans; Infection; Infections; Infectious diseases; Influenza; Influenza A Virus, H1N1 Subtype; Influenza Vaccines; Influenza viruses; Influenza, Human; Japan; Male; Medicine; Medicine and Health Sciences; Middle Aged; Neuraminidase; Neuraminidase inhibitors; Pandemics; Patient outcomes; People and Places; Population; Prevention; Q; R; Research Article; Science; Seroconversion; Vaccination; Vaccines; Vaccines, Inactivated; Viral infections; Viral Proteins; Viral research; Viruses; Young Adult; Japan; United States > US; California
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0233001

Antibodies against influenza virus neuraminidase (NA) protein prevent releasing of the virus from host cells and spreading of infection foci and are considered the 'second line of defence' against influenza. Haemagglutinin inhibition antibody-low responders (HI-LRs) are present among influenza split vaccine recipients. The NA inhibition (NAI) antibody response in vaccinees is worth exploring, especially those in the HI-LRs population. We collected pre- and post-vaccination sera from 61 recipients of an inactivated, monovalent, split vaccine against A/H1N1pdm09 and acute and convalescent sera from 49 unvaccinated patients naturally infected with the A/H1N1pdm09 virus during the 2009 influenza pandemic. All samples were subjected to haemagglutinin inhibition (HI), NAI and neutralisation assays. Most paired sera from naturally infected patients exhibited marked elevation in the NAI activity, and seroconversion rates (SCR) among HI-LRs and HI-responders (HI-Rs) were 60% and 87%, respectively; however, those from vaccinees displayed low increase in the NAI activity, and the SCR among HI-LRs and HI-Rs were 0% and 12%, respectively. In both HI-LRs and HI-Rs, vaccination with the inactivated, monovalent, split vaccine failed to elicit the NAI activity efficiently in the sera of the naive population, compared with the natural infection. Hence, the improvement of influenza vaccines is warranted to elicit not only HI but also NAI antibodies.