Influenza In Vitro

Influenza viruses (INFV) are segmented RNA viruses that cause seasonal influenza epidemics and influenza pandemics. INFV A infects birds and some mammals (e.g. pigs and humans), while VFV B only infects humans and seals. Both Influenza A and B pose a severe threat to public health and the agricultural economy. Influenza viruses mutate quickly by antigenic drift and reassortment, re- quiring the development and reformulation of new vaccines each year. Influenza strains resistant to almost all known drugs have been identified, making influenza drug development a high priority. Con- cerns about INFV have been further heightened due to the potential for transmission of highly patho- genic avian influenza (HPAI) strains to humans.

MDCK cells infected and CPE detected using a standard crystal violet staining

Vero cells infected and viral plaque detected by a standard immunoplaque assay

INFV plaque formation in PRNT 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