2 September 2020

Viral antigen bank by Sino Biological

Sino Biological launches the world largest recombinant viral antigen collection, ProVir™, which includes over 1000 products from 90 different types, 350 strains of viruses.

Recombinant antigens are key reagents in infectious disease research. They are widely used in the context of antibody and vaccine development. In addition, high-quality antigens and antibodies are critical components in immunodiagnostic assays.

Sino Biological Inc. launches the world’s largest recombinant viral antigen collection, ProVir™, which includes over 1000 products from 90 different types/subtypes and 350 strains of viruses. The product line features a wide range of high quality recombinant proteins expressed in insect and mammalian cells. These products are rigorously tested for their purity and bioactivity.

This unique portfolio includes the one-of-a-kind coronavirus catalog, a huge collection of infleunza antigens from over 250 strains, and many other hard-to-find viral proteins such as RSV, Ebola, and Cytomegalovirus. These reagents are specifically developed to help vaccine research and drug development.

Research reagents by virus types

CHIKVHAdV-BInfluenza virusSABV
Dengue virusHCVMERS-CoVVaccinia virus
Ebola virusHIVNiVVSIV
EV-D68HPVRSVZika virus
Click on a virus type and go directly to the products.

Human coronavirus

Coronavirus are positive sense, single stranded RNA viruses. There are seven types of coronaviruses known to infect humans. Patients infected with these viruses develop respiratory symptoms of various severity. HCoV-229E and HCoV-OC43, the two coronaviruses discovered in early years, cause common cold. The other five coronaviruses lead to more severe respiratory tract infection, which can potentially be lethal. Since 2000, there have been three major world-wide health crisis caused by coronaviruses, the 2003 SARS outbreak, the 2012 MERS outbreak, and the 2019 COVID-19 outbreak. Thousands of people died during these epidemics, while surprisingly no vaccine, treatment, or diagnostic has been established. The outbreak of COVID-19 is yet another wake-up call for the biomedical community to make serious efforts to understand the biology of these viruses, and find ways to prevent and treat the infections.

SARS-CoV-2BetacoronavirusCoronavirus disease 2019 (COVID-19). As of 14th July, >130M infected, >572K death.
SARS-CoVBetacoronavirusSevere acute respiratory syndrome (SARS), mortality rate 9%
MERS-CoVBetacoronavirusMiddle East respiratory syndrome (MERS), mortality rate >30%
HCoV-HKU1BetacoronavirusMild respiratory disease
HCoV-NL63AlphacoronavirusMild respiratory disease
HCoV-OC43BetacoronavirusMild respiratory disease
HCoV-229EAlphacoronavirusMild respiratory disease
Click on a virus type and go directly to the products.

All coronaviruses share very similar structures. The viral genome encodes several proteins of unique functions, including Spike protein, N protein, HE protein, papain-like proteases, and M protein. The two antigens of main pharmaceutical interest are the S (spike) protein and the N protein. The N (nucleocapsid) protein is often conserved, which can be used as a diagnostic marker. The Spike protein is mainly responsible for receptor binding, and is a common target for vaccines and antibodies.

The spike protein is particular important as its interaction with the host cell receptor is the pivotal step during the infection. Different viruses may utilize different surface receptor for binding. The HCOV- NL63, SARS-COV, and the new SARS-COV-2 viruses all use the ACE2 receptor, while the MERS-COV virus selectively binds with the DPP4 receptor. The HCOV-229E virus targets APN receptor. The rest two common coronavirus, HKU1 and OC43 bind with O-ac Sia.

Influenza virus

Influenza (flu) is a respiratory infection in mammals and birds. It is caused by an RNA virus in the family Orthomyxoviridae. Influenza virus is divided into four main types (Influenza A, Influenza B, Influenza C, Influenza D), which are distinguished by differences in two major internal proteins (hemagglutinin (HA) and neuraminidase (NA)). Three of the four types of influenza viruses affect humans: Type A, Type B, and Type C. Type D has not been known to infect humans, but is believed to have the potential to do so. Influenza virus type A is found in a wide variety of bird and mammal species and can undergo major shifts in immunological properties. Influenza virus type B is largely confined to humans and is an important cause of morbidity.

Little is known about Influenza virus type C, which is not an important source of morbidity. Influenza D was identified in 2016.

Classification / types of Influenza virus

Influenza AInfluenza BInfluenza C
HostsHumans, waterfowl, poultry, pigs, horses, sea mammals, batsHumans, sealsHumans, pigs, dogs
Gene segments887
HA/NA antigenic subtypes18 HA, 11 NANoneNone
Clinical featuresModerate to severe illnessMilder disease than Influenza ALargely subclinical
Epidemiological featuresCauses pandemicsLess severe epidemics than Influenza A; no pandemicsDoes not cause epidemics or pandemics

Influenza A virus is further divided into subtypes based on differences in the membrane proteins hemagglutinin (HA) and neuraminidase (NA), which are the most important targets for the immune system. The notation HhNn is used to refer to the subtype comprising the hth discovered Hemagglutinin (HA) protein and the nth discovered neuraminidase (NA) protein.

List of all subtype

H1 SubtypeH1N1H1N2H1N3H1N8H1N9
H2 SubtypeH2N2H2N3H2N8
H3 SubtypeH3N1H3N2H3N8
H4 SubtypeH4N2H4N4H4N6H4N8
H5 SubtypeH5N1H5N2H5N3H5N6H5N8H5N9
H6 SubtypeH6N1H6N2H6N4H6N5H6N6H6N8
H7 SubtypeH7N1H7N2H7N3H7N7H7N8H7N9
H8 SubtypeH8N4
H9 SubtypeH9N1H9N2H9N5H9N8
H10 SubtypeH10N3H10N4H10N7H10N8H10N9
H11 SubtypeH11N2H11N6H11N9
H12 SubtypeH12N1H12N3H12N5
H13 SubtypeH13N6H13N8
H14 SubtypeH14N5
H15 SubtypeH15N2H15N8
H16 SubtypeH16N3
H17 SubtypeH17N10
H18 SubtypeH18N11
B influenzaInfluenza B
Click on a subtype and go directly to the products.

The influenza viral Hemagglutinin (HA) protein is a homo trimer with a receptor binding pocket on the globular head of each monomer, and the influenza viral neuraminidase (NA) protein is a tetramer with an enzyme active site on the head of each monomer. Subtypes are further divided into strains; each genetically distinct virus isolate is usually considered to be a separate strain.


  1. Tony Mazzulli, in Principles and Practice of Pediatric Infectious Diseases (Fifth Edition), 2018;
  2. David R. Peaper, Marie Louise Landry, in Handbook of Clinical Neurology, 2014;
  3. Stephen N.J. Korsman MMed FCPath, … Wolfgang Preiser MRCPath, in Virology, 2012;
  4. Anthony R. Fehr and Stanley Perlman. Coronaviruses: An Overview of Their Replication and Pathogenesis. Methods Mol Biol., 2015;
  5. R.J.G. Hulswit. Coronavirus Spike Protein and Tropism Changes. Advances in Virus Research, 2016;
  6. Yudong Yin and Richard G. Wunderink. MERS, SARS and other coronaviruses as causes of pneumonia. Asian Pacific Society of Respirology, 2017;
  7. Xintian Xu.Evolution of the novel coronavirus from the ongoing Wuhan outbreak and modeling of its spike protein for risk of human transmission. Science China Life Sciences, 2020;
  8. Dan Dou. Influenza A Virus Cell Entry, Replication, Virion Assembly and Movement. Front Immunol. 2018; 9: 1581;
  9. Scott H. James, Richard J. Whitley, in Infectious Diseases (Fourth Edition), 2017;
  10. Donald J. Benton, Influenza hemagglutinin membrane anchor, PNAS, 2018 115 (40):10112-10117;
  11. Steven J. Gamblin, Influenza Hemagglutinin and Neuraminidase Membrane Glycoproteins, J Biol Chem. 2010 Sep 10; 285(37): 28403–28409;
  12. Wilson IA. 1981. Structure of the haemagglutinin membrane glycoprotein of influenza virus at 3 A resolution. Nature. 289 (5796): 366–73;
  13. Boonstra S. 2018. Hemagglutinin-Mediated Membrane Fusion: A Biophysical Perspective. Annual Review of Biophysics. 47 (1): 153–173;
  14. Y.A. Shtyrya. Influenza Virus Neuraminidase: Structure and Function. Acta Naturae. 2009 Jul; 1(2): 26–32;
  15. Russell R.J. The structure of H5N1 avian influenza neuraminidase suggests new opportunities for drug design. Nature. 2006;44:45–49;
  16. Julie L. McAuley. Influenza Virus Neuraminidase Structure and Functions. Front. Microbiol., 29 January 2019.

Find the product you need

All product groups

Related articles

Newsletter for researchers

We gladly support you by keeping you updated on our latest products and the developments around our services.

we Connect you
Need help? Contact our technical support