BACKGROUND: The influenza A(H1N1)2009 virus has been spreading throughout the world since April 2009. Since then, several studies have been undertaken to measure the frequency of antibodies that react against the virus. Microneutralisation assays have regularly been used for these analyses, and titres of ≥40 have conventionally been taken to represent significant levels of antibodies (this significance is derived from it being four times the minimum level of antibodies that the assay can detect rather an established correlate of protection). However a microneutralisation titre that correlates with protection against influenza A(H1N1)2009 has not been established. OBJECTIVES: Analysing influenza A(H1N1)2009 antibody seroprevalence in Scotland at multiple timepoints, and in different age groups and geographical locations, and comprehensively describing the spread of the virus in Scotland (taken alongside previously published data). This study presents for the first time the effects of a novel influenza virus on a naïve population that has been followed from the initial outbreak to a time when the majority of the population have reactive antibodies. STUDY DESIGN: A microneutralisation titre ≥10 represents the minimum level of antibodies detectable by the assay. Blood samples (taken in April 2009 and April 2010 in Edinburgh (n=400 each year), and in February 2011 in Aberdeen, Edinburgh, Glasgow, and Inverness (n=1600)) were tested for the presence of influenza A(H1N1)2009 antibodies at this titre. This represents an effective indicator of the proportion of a population who have been exposed to the virus. RESULTS: Following the 2010/2011 influenza season, there is evidence of exposure to influenza A(H1N1)2009 in approximately four fifths of the Scottish population. CONCLUSIONS: This study provides impetus to the call for further research in establishing robust correlates of susceptibility to influenza infection and the development of clinical illness, provides useful information for future outbreaks, and is relevant to public health policy in planning for future influenza seasons.
BACKGROUND: The influenza A(H1N1)2009 virus has been spreading throughout the world since April 2009. Since then, several studies have been undertaken to measure the frequency of antibodies that react against the virus. Microneutralisation assays have regularly been used for these analyses, and titres of ≥40 have conventionally been taken to represent significant levels of antibodies (this significance is derived from it being four times the minimum level of antibodies that the assay can detect rather an established correlate of protection). However a microneutralisation titre that correlates with protection against influenza A(H1N1)2009 has not been established. OBJECTIVES: Analysing influenza A(H1N1)2009 antibody seroprevalence in Scotland at multiple timepoints, and in different age groups and geographical locations, and comprehensively describing the spread of the virus in Scotland (taken alongside previously published data). This study presents for the first time the effects of a novel influenza virus on a naïve population that has been followed from the initial outbreak to a time when the majority of the population have reactive antibodies. STUDY DESIGN: A microneutralisation titre ≥10 represents the minimum level of antibodies detectable by the assay. Blood samples (taken in April 2009 and April 2010 in Edinburgh (n=400 each year), and in February 2011 in Aberdeen, Edinburgh, Glasgow, and Inverness (n=1600)) were tested for the presence of influenza A(H1N1)2009 antibodies at this titre. This represents an effective indicator of the proportion of a population who have been exposed to the virus. RESULTS: Following the 2010/2011 influenza season, there is evidence of exposure to influenza A(H1N1)2009 in approximately four fifths of the Scottish population. CONCLUSIONS: This study provides impetus to the call for further research in establishing robust correlates of susceptibility to influenza infection and the development of clinical illness, provides useful information for future outbreaks, and is relevant to public health policy in planning for future influenza seasons.
Authors: Jodie McVernon; Karen Laurie; Helen Faddy; David Irving; Terry Nolan; Ian Barr; Anne Kelso Journal: Influenza Other Respir Viruses Date: 2013-12-31 Impact factor: 4.380
Authors: Xuexiang Lin; Xiao-Yu Liu; Bo Zhang; Ai-Qing Qin; Kwok-Min Hui; Kevin Shi; Yang Liu; Don Gabriel; X James Li Journal: Sci Rep Date: 2022-01-11 Impact factor: 4.379
Authors: Saranya Sridhar; Shaima Begom; Katja Hoschler; Alison Bermingham; Walt Adamson; William Carman; Steven Riley; Ajit Lalvani Journal: Am J Respir Crit Care Med Date: 2015-02-01 Impact factor: 21.405