Immunogenicity of high-dose MVA-based MERS vaccine candidate in mice and camels

Journal article

The Middle East respiratory syndrome coronavirus (MERS-CoV) is a zoonotic pathogen that can transmit from dromedary camels to humans, causing severe pneumonia, with a 35% mortality rate. Vaccine candidates have been developed and tested in mice, camels, and humans. Previously, we developed a vaccine based on the modified vaccinia virus Ankara (MVA) viral vector, encoding a full-length spike protein of MERS-CoV, MVA-MERS. Here, we report the immunogenicity of high-dose MVA-MERS in prime–boost vaccinations in mice and camels. Methods: Three groups of mice were immunised with MVA wild-type (MVA-wt) and MVA-MERS (MVA-wt/MVA-MERS), MVA-MERS/MVA-wt, or MVA-MERS/MVA-MERS. Camels were immunised with two doses of PBS, MVA-wt, or MVA-MERS. Antibody (Ab) responses were evaluated using ELISA and MERS pseudovirus neutralisation assays. Results: Two high doses of MVA-MERS induced strong Ab responses in both mice and camels, including neutralising antibodies. Anti-MVA Ab responses did not affect the immune responses to the vaccine antigen (MERS-CoV spike). Conclusions: MVA-MERS vaccine, administered in a homologous prime–boost regimen, induced high levels of neutralising anti-MERS-CoV antibodies in mice and camels. This could be considered for further development and evaluation as a dromedary vaccine to reduce MERS-CoV transmission to humans.

Authors: Alharbi, NK; Aljamaan, F; Aljami, HA; Alenazi, MW; Albalawi, H

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: MDPI
• Journal: Vaccines
• Volume: 10
• Issue: 8
• Article number: 1330
• Place of publication: Switzerland
• Publication date: 2022-08-17
• Acceptance date: 2022-08-15
• DOI: 10.3390/vaccines10081330
• EISSN: 2076-393X
• Pmid: 36016218
• Language: English
• Keywords: MVA; MERS-CoV; viral vector; vaccine; antibody; camel; mice