Development of a Vaccine Candidate for Crimean-Congo Haemorrhagic Fever Virus

1. Development of a vaccine candidate against Crimean-Congo Haemorrhagic Fever (CCHF) virus Dr Stuart Dowall Project Team Leader Virology and Pathogenesis group

2. Background Crimean-Congo Haemorrhagic Fever (CCHF) virus: • Severe human infection. • Fatality rate 30% (9-50%). • No FDA or European approved vaccine or treatment. • Transmission by tick bite or contact with • infected blood/body fluids. • ACDP hazard group 4 pathogen. 2 Preclinical development of the PHE CCHF vaccine PHE pipeline fund PLF 1516/108/MR Development of a vaccine against CCHF virus

3. Why is it important to PHE? 2. Increased incidence in tourism areas. • 1. Spread of vector across Europe. Development of a vaccine against CCHF virus

4. Why is it important to PHE? 5. Threat to armed forces. • 3. Threat is national and international 4. Increases PHE international profile Development of a vaccine against CCHF virus

5. Why is it important to PHE? 7. Maintain emergency response capability so expertise available. • 6. Potential bioweapon • Negative sense RNA genome giving high rate of mutations. • Segmented genome allows genetic reassortment of viruses. • Existence of an animal reservoir. • Highly pathogenic (requiring Containment Level 4 facilities). • Large risk of nosocomial spread within hospitals. Development of a vaccine against CCHF virus

6. Lack of treatments against CCHF No vaccines or antiviral drugs are approved for CCHF by FDA or EMA. Bulgarian vaccine candidate has major disadvantages: • Requires live CCHF virus • Crude preparation (non-standardised homogenisation of mouse brain) • No efficacy studies, no interest to generate data package since 70s • Is not acceptable to FDA/MHRA/EMA approval • Alternative approach badly needed for a modern CCHF vaccine that can meet regulatory approval and is proven to be effective. Development of a vaccine against CCHF virus

7. Development of the vaccine candidate Our approach:We have used Modified Vaccinia Ankara (MVA) as a viral vector to induce immune responses against an inserted CCHF protein antigen. Properties of MVA that make it attractive: • Human safety history: >100,000 doses in 1970s with no adverse effects. • Human cells non-permissive. • Induction of humoral and cellular immunity. • Industrial GMP established. • Thermostable. • Production of recombinant proteins. • Clear commercial opportunities • Vaxgene, Baxter, Bavarian Nordic, Emergent  all in clinical trials with MVA-based vaccines. • Approximately extra 100,000 people vaccinated with no adverse signs. • Inexpensive, low cost approach Development of a vaccine against CCHF virus

8. Development of the vaccine candidate Glycoprotein Antigen sequence GFP for selection of recombinant viruses N-terminal tPA for secretion & Nab induction C-terminal V5 for in vitro antibody recognition L R L R MVA genome L R Transfer plasmid MVA GFP+ plaque purification L R MVA permissive cell Development of a vaccine against CCHF virus

9. Confirmation of antigen expression CCHF+ SW13 SW13 cells MVA-1974 positive control MVA-GP MVA-GP Anti-V5 antibody (expected size of GP-V5 fusion protein = 76.6kDa, positive control protein = 62kDa) Anti-CCHF rabbit polyclonal sera (similar post-translational cleavages in MVA-GP to native protein) Development of a vaccine against CCHF virus

10. The vaccine induces cellular immunity… IFN-g ELISPOT assay Solid bars = 129Sv/Ev mice; hatched bars = A129 mice Media Summed antigen responses Individual peptide pools GP peptides Similar responses in 129Sv/Ev and A129 mice were detected. Immunogenicity was not evenly distributed across the antigen. Responses were specific to the glycoprotein, and similar between mouse strains. Development of a vaccine against CCHF virus

11. …and humoral immunity. CCHFv-infected SW13 cells Western blot Uninfected SW13 cells ELISA studies The MVA-GP vaccine induced significant CCHF glycoprotein-specific antibodies. Development of a vaccine against CCHF virus

12. CCHF Challenge Analysis Boost Prime • Efficacy studies Day 0 7 14 21 28 35 42 100% protection from lethal challenge  First demonstration of CCHF vaccine efficacy Development of a vaccine against CCHF virus

13. Viral loads RT-PCR for CCHFv gene expression (normalised to mouse HPRT gene expression). Day 32 = 4 days post-challenge Day 42 = 14 days post-challenge (end of study) Viral load was significantly lower in MVA-GP vaccinated mice than in control groups. Blood Spleen Liver Development of a vaccine against CCHF virus

14. Spleen Liver • Histology H&E staining Immunised A129 mice, 4 days post-challenge MVA-1974 Marked lymphocyte loss with prominent apoptotic bodies, and infiltration by macrophages. Marked, multifocally extensive hepatocyte necrosis (arrows). MVA-GP A single infiltration of macrophages in the white pulp (asterisk) (scored minimal). Scattered, multifocal areas of hepatocellular necrosis with a mixed inflammatory cell infiltrate (arrows) (scored moderate). Development of a vaccine against CCHF virus

15. Spleen Liver • Histology Immunostaining Immunised A129 mice, 4 days post-challenge MVA-1974 A few, scattered cells with cytoplasmic staining within the parenchyma. Frequent, diffuse, positively stained hepatocytes. MVA-GP Normal parenchyma. A few, positively stained cells within an inflammatory cell focus. Development of a vaccine against CCHF virus

16. Next steps Isolate splenocytes (T-cells) and sera (antibody) from immunised mice Immunise mice with MVA-GP Adoptively transfer splenocytes into naïve mice Passively transfer sera into naïve mice Challenge with CCHF virus Determine survival effects Development of a vaccine against CCHF virus

17. Market sizing • CCHF represents a niche market • Main opportunity in military based on a range of between $33.1 – $57.1 million • Market only likely to be capable of supporting a single manufacturer and heavily reliant on military Development of a vaccine against CCHF virus

18. Summary • CCHF is a real and growing threat – most widespread VHF across Europe/Asia Africa. • PHE’s vaccine candidate is promising with efficacy proof of concept in mouse model. • Next step is to confirm mechanism of action (passive/adoptive transfer studies). Development of a vaccine against CCHF virus