An overview of Middle East respiratory syndrome coronavirus vaccines in preclinical studies

Abstract

Introduction: Middle East respiratory syndrome coronavirus (MERS-CoV) causes high mortality in humans. No vaccines are approved for use in humans; therefore, a consistent effort to develop safe and effective MERS vaccines is needed. Areas covered: This review describes the structure of MERS-CoV and the function of its proteins, summarizes MERS vaccine candidates under preclinical study (based on spike and non-spike structural proteins, inactivated virus, and live-attenuated virus), and highlights potential problems that could prevent these vaccines entering clinical trials. It provides guidance for the development of safe and effective MERS-CoV vaccines. Expert opinion: Although many MERS-CoV vaccines have been developed, most remain at the preclinical stage. Some vaccines demonstrate immunogenicity and efficacy in animal models, while others have potential adverse effects or low efficacy against high-dose or divergent virus strains. Novel strategies are needed to design safe and effective MERS vaccines to induce broad-spectrum immune responses and improve protective efficacy against multiple strains of MERS-CoV and MERS-like coronaviruses with pandemic potential. More funds should be invested to move vaccine candidates into human clinical trials.

Pandemics Throughout History

“…The WHO calls for the development of three types of vaccines against MERS-CoV: a human vaccine that is intended for long-term protection of individuals at high-risk of exposure such as health care workers and those having contacts with potentially infected dromedary camels, a human vaccine for use during outbreaks and a dromedary camel vaccine to prevent zoonotic transmission ( World Health Organization [WHO], 2017b ). The spike protein of MERS-CoV is an important target for the development of vaccines ( Zhang N. et al, 2020 ). These vaccines are based on DNA, viral vectors, viral proteins, virus-like particles, bacterium-like particles and nanoparticles.…”

Advances in mRNA and other vaccines against MERS-CoV

“…Othocoronavirinae consists of four genera: alpha-CoV, beta-CoV, gamma-CoV, and delta-CoV. 1,2 Middle East respiratory syndrome (MERS)-CoV, severe acute respiratory syndrome (SARS)-CoV-1, and SARS-CoV-2 are three highly pathogenic human CoVs that are classified as beta-CoVs. [1][2][3] Phylogenetically, MERS-CoV is a member of lineage C of beta-CoV, whereas SARS-CoV-1 and SARS-CoV-2 are classified as members of lineage B of beta-CoV.…”

“…1,2 Middle East respiratory syndrome (MERS)-CoV, severe acute respiratory syndrome (SARS)-CoV-1, and SARS-CoV-2 are three highly pathogenic human CoVs that are classified as beta-CoVs. [1][2][3] Phylogenetically, MERS-CoV is a member of lineage C of beta-CoV, whereas SARS-CoV-1 and SARS-CoV-2 are classified as members of lineage B of beta-CoV. 2,4 SARS-CoV-1 and SARS-CoV-2 were first reported in humans in 2002 and 2019, respectively, leading to the global outbreak or pandemic.…”

“…[1][2][3] Phylogenetically, MERS-CoV is a member of lineage C of beta-CoV, whereas SARS-CoV-1 and SARS-CoV-2 are classified as members of lineage B of beta-CoV. 2,4 SARS-CoV-1 and SARS-CoV-2 were first reported in humans in 2002 and 2019, respectively, leading to the global outbreak or pandemic. [5][6][7] The first MERS-CoV infection in humans was reported in June 2012.…”

“…1A, B). 1,2,20 These proteins have different functions in viral transcription, translation, assembly, infection, replication, and pathogenesis. 2 Among these, the S protein plays a critical role in viral infection and pathogenesis.…”