Prospects for a MERS-CoV spike vaccine

Area of Science:

• Virology
• Immunology
• Vaccinology

Background:

• Middle East respiratory syndrome coronavirus (MERS-CoV), first identified in 2012, poses a significant public health threat due to its high human mortality rate.
• Despite the persistent threat, no vaccines are currently approved for human use against MERS-CoV infection.

Purpose of the Study:

• To review the structure and function of the MERS-CoV spike (S) protein as a vaccine target.
• To describe animal models used for evaluating MERS vaccines.
• To summarize progress in MERS-CoV S-protein-based vaccine development, focusing on immune responses and protection.

Main Methods:

• Literature review of MERS-CoV S-protein-based vaccine candidates.
• Analysis of studies evaluating vaccine immunogenicity (antibody and cellular responses) and efficacy in animal models.
• Assessment of different MERS-CoV S protein constructs (full-length S, S1, RBD) as vaccine platforms.

Main Results:

• Most MERS vaccines in development utilize the MERS-CoV S protein, including full-length S, S1 subunit, and the receptor-binding domain (RBD).
• Vaccines based on S protein have shown varying abilities to elicit antibody and cellular immune responses, including neutralizing antibodies.
• Protection against MERS-CoV infection has been demonstrated in different animal models using S-based vaccines, with specific strategies needed to enhance RBD-based vaccine efficacy.

Conclusions:

• The MERS-CoV S protein is a primary target for vaccine development.
• Evaluating the safety of full-length S and S1-based vaccines is crucial.
• Further optimization of RBD-based MERS vaccines is necessary for improved efficacy.
• This review offers guidance for developing safe and effective MERS vaccines targeting the viral S protein.