Alphaviruses In-Vitro

Alphaviruses are arthropod-borne viruses that cause disease in humans and a wide range of domestic and agricultural animals. Interest in the development of alphavirus therapeutics and vaccines has risen in recent years due to epidemics of Chikungunya virus (CHIKV) causing severe illness in Africa and Asia and concerns about possible use of Venezuelan equine encephalitis virus (VEEV) as an agent of bioterrorism.

A major obstacle in the development of antivirals for alphaviruses is the requirement for the work to be performed in a costly high-containment BSL-3 laboratory. IBT Bioservices has established reliable in vitro assays for alphaviruses using attenuated strains of CHIKV and VEEV, allowing testing in a BSL-2 environment.

Our attenuated alphaviruses include CHIKV 181/25, a well-known experimental vaccine strain, and VEEV TC-83, derived from the highly pathogenic strain Trinidad Donkey (TrD).

  • Vero cells infected and CPE detected using a standard crystal violet staining
  • Boxed point is excluded from the curve fitting of CPE assay  due to the interference from cytotoxicity

  • Vero cells infected and cell supernatants titrated using a standard plaque assay
Fig. 1 Survival after challenge with INFV H1N1 A/Pert/261/2009 (Tamiflu-resistant strain). Inoculum 1xLD90=1.0E+05 PFU/mouse
Survival after challenge with INFV H1N1 A/Pert/261/2009 (Tamiflu-resistant strain) 1.0E+05 PFU/mouse
Survival and weight change in BALB/c mice challenged with INFV A/ Texas/36/91 (H1N1) and treated with antiviral Osletamivir Phosphate (Tamiflu)
Lung viral load and Survival (30 % weight loss cut-off) in BALB/c mice challenged with INFV H3N2 A/HK/1/68.

Alpha (UK) – B. 1.1.7 / 501Y.V1

amino acid mutations: del69–70 HV, del144 Y, N501Y, A570D, D614G, P681H, T761I, S982A, D1118H

Beta (South Africa) – B.1.351

amino acid mutations: K417N, E484K, N501Y, D614G, A701V

Gamma (Brazil) – P.1

amino acid mutations: L18F, T20N, P26S, D138Y, R190S, K417T, E484K, N501Y, D614G, H655Y, T1027I

Epsilon (Ca, USA) B.1.427

amino acid mutations: L452R, D614G

SARS-CoV-2 Parental Strain Wild Type (Wuhan)
SARS-CoV-2 D614G Variant

amino acid mutations: D614G

Epsilon (Ca, USA) B.1.429

amino acid mutations: S13I, W152C, L452R, D614G

SARS-CoV-2 Delta Variant

amino acid mutations: L452R, E484Q