Development of humanised antibodies for Crimean-Congo Haemorrhagic fever virus: Comparison of hybridoma-based versus phage library techniques

Humanised antibodies targeting Crimean-Congo Haemorrhagic virus (CCHFV) are needed for the development and standardisation of serological assays. These assays are needed to address a shortfall in available tests that meet regulatory diagnostic standards and to aid surveillance activities to extend knowledge on the distribution of CCHFV. To generate a humanised monoclonal antibody against CCHFV, we have compared two methods: the traditional mouse hybridoma approach with subsequent sequencing and humanisation of antibodies versus a non-animal alternative using a human combinatorial antibody library (HuCAL). Our results demonstrated that the mouse hybridoma followed by humanisation protocol gave higher affinity antibodies. Whilst not yet able to demonstrate the generation of equivalent humanised antibodies without the use of animals, sequencing data enables the subsequent production of recombinant antibodies, thus providing a reduction in future animal usage for this application. Ultimately, our report provides information on development of a humanised standardised control, which can form an important positive control component of serological assays against CCHFV.