Examination of seroprevalence of coronavirus HKU1 infection with S protein-based ELISA and neutralization assay against viral spike pseudotyped virus

J Clin Virol. 2009 May;45(1):54-60. doi: 10.1016/j.jcv.2009.02.011. Epub 2009 Apr 1.


Background: Human coronavirus HKU1 (HCoV-HKU1) is a recently identified coronavirus with a global distribution and known to cause mainly respiratory infections.

Objectives: To investigate the seroepidemiology of HKU1 infections in our local population.

Study design: An ELISA-based IgG antibody detection assay using recombinant HCoV-HKU1 nucleocapsid and spike (S) proteins (genotype A) were developed for the diagnosis of CoV-HKU1 infections, Additionally, a neutralization antibody assay using the HCoV-HKU1 pseudotyped virus was developed to detect the presence of neutralizing antibodies in serum with antibody positivity in an S protein-based ELISA.

Results: Results of the recombinant S protein-based ELISA were validated with Western blot, immunofluorescence analysis and flow cytometry. The coupled results demonstrated good correlation with Spearmen's coefficient of 0.94. Seroepidemiological study in a local hospital-based setting using this newly developed ELISA showed steadily increasing HCoV-HKU1 seroprevalence in childhood and early adulthood, from 0% in the age group of <10 years old to a plateau of 21.6% in the age group of 31-40 years old.

Conclusions: Our study demonstrated the usefulness of the S-based ELISA which could be applied to future epidemiological studies of HCoV-HKU1 in other localities.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Animals
  • Antibodies, Viral / blood*
  • Antigens, Viral / immunology
  • Cell Line
  • Child
  • Coronavirus / immunology*
  • Coronavirus Infections / epidemiology*
  • Coronavirus Infections / immunology
  • Coronavirus Nucleocapsid Proteins
  • Enzyme-Linked Immunosorbent Assay*
  • Hong Kong
  • Humans
  • Membrane Glycoproteins / immunology*
  • Microscopy, Fluorescence
  • Middle Aged
  • Neutralization Tests*
  • Nucleocapsid Proteins / immunology
  • Recombinant Proteins / immunology
  • Reproducibility of Results
  • Seroepidemiologic Studies
  • Spike Glycoprotein, Coronavirus
  • Statistics, Nonparametric
  • Viral Envelope Proteins / immunology*


  • Antibodies, Viral
  • Antigens, Viral
  • Coronavirus Nucleocapsid Proteins
  • Membrane Glycoproteins
  • Nucleocapsid Proteins
  • Recombinant Proteins
  • Spike Glycoprotein, Coronavirus
  • Viral Envelope Proteins
  • spike glycoprotein, SARS-CoV
  • spike protein, mouse hepatitis virus