1 Laboratory of Vaccine and Biomolecules, Institute of Bioscience, Universiti Putra Malaysia, Serdang, Selangor, Malaysia; Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia.
2 UK Health Security Agency, Porton Down, Salisbury SP4 0JG, UK. Electronic address: karen.buttigieg@ukhsa.gov.uk.