Bispecific antibody generated with sortase and click chemistry has broad antiinfluenza virus activity.

Bispecific antibodies have therapeutic potential by expanding the functions of conventional antibodies. Many different formats of bispecific antibodies have meanwhile been developed. Most are genetic modifications of the antibody backbone to facilitate incorporation of two different variable domains into a single molecule.

Rapid emergence of a virulent PB2 E627K variant during adaptation of highly pathogenic avian influenza H7N7 virus to mice.

Background: Highly pathogenic avian influenza (HPAI) viruses pose a potential human health threat as they can be transmitted directly from infected poultry to humans. During a large outbreak of HPAI H7N7 virus among poultry in The Netherlands in 2003, bird to human transmission was confirmed in 89 cases, of which one had a fatal outcome.

Methods: To identify genetic determinants of virulence in a mammalian host, we passaged an avian H7N7/03 outbreak isolate in mouse lungs and evaluated the phenotype of the mouse-adapted variant in animal models and in vitro.

Protective efficacy of Newcastle disease virus expressing soluble trimeric hemagglutinin against highly pathogenic H5N1 influenza in chickens and mice.

Background: Highly pathogenic avian influenza virus (HPAIV) causes a highly contagious often fatal disease in poultry, resulting in significant economic losses in the poultry industry. HPAIV H5N1 also poses a major public health threat as it can be transmitted directly from infected poultry to humans. One effective way to combat avian influenza with pandemic potential is through the vaccination of poultry.

Glycan-dependent immunogenicity of recombinant soluble trimeric hemagglutinin.

Recombinant soluble trimeric influenza A virus (IAV) hemagglutinin (sHA(3)) has proven an effective vaccine antigen against IAV. Here, we investigate to what extent the glycosylation status of the sHA(3) glycoprotein affects its immunogenicity. Different glycosylation forms of subtype H5 trimeric HA protein (sH5(3)) were produced by expression in insect cells and different mammalian cells in the absence and presence of inhibitors of N-glycan-modifying enzymes or by enzymatic removal of the oligosaccharides.

Variants of the recently discovered avian gyrovirus 2 are detected in Southern Brazil and The Netherlands.

A genome of a virus preliminarily named avian gyrovirus 2 (AGV2), a close relative to chicken anemia virus, was recently discovered in a chicken in the state of Rio Grande do Sul, Southern Brazil. To study the occurrence of AGV2 in Rio Grande do Sul and the neighboring state Santa Catarina, a number of adult chickens (n=108 and n=48, respectively) were tested for the presence of AGV2 DNA. An AGV2-specific PCR was developed, optimized and used to analyze DNA extracted from clinical samples.

A highly conserved neutralizing epitope on group 2 influenza A viruses.

Current flu vaccines provide only limited coverage against seasonal strains of influenza viruses. The identification of V(H)1-69 antibodies that broadly neutralize almost all influenza A group 1 viruses constituted a breakthrough in the influenza field. Here, we report the isolation and characterization of a human monoclonal antibody CR8020 with broad neutralizing activity against most group 2 viruses, including H3N2 and H7N7, which cause severe human infection.

A single immunization with soluble recombinant trimeric hemagglutinin protects chickens against highly pathogenic avian influenza virus H5N1.

Background: The highly pathogenic avian influenza (HPAI) virus H5N1 causes multi-organ disease and death in poultry, resulting in significant economic losses in the poultry industry. In addition, it poses a major public health threat as it can be transmitted directly from infected poultry to humans with very high (60%) mortality rate. Effective vaccination against HPAI H5N1 would protect commercial poultry and would thus provide an important control measure by reducing the likelihood of bird-to-bird and bird-to-human transmission.

Pre- and postexposure use of human monoclonal antibody against H5N1 and H1N1 influenza virus in mice: viable alternative to oseltamivir.

New strategies to prevent and treat influenza virus infections are urgently needed. A recently discovered class of monoclonal antibodies (mAbs) neutralizing an unprecedented spectrum of influenza virus subtypes may have the potential for future use in humans. Here, we assess the efficacies of CR6261, which is representative of this novel class of mAbs, and oseltamivir in mice.

Challenges for porcine reproductive and respiratory syndrome virus (PRRSV) vaccinology.

Porcine reproductive and respiratory syndrome virus (PRRSV) continues to be a threat for the pig industry. Vaccines have been developed, but these failed to provide sustainable disease control, in particular against genetically unrelated strains. Here we give an overview of current knowledge and gaps in our knowledge that may be relevant for the development of a future generation of more effective vaccines.