Middle East respiratory syndrome: obstacles and prospects for vaccine development

Abstract

The recent emergence of Middle East respiratory syndrome (MERS) highlights the need to engineer new methods for expediting vaccine development against emerging diseases. However, several obstacles prevent pursuit of a licensable MERS vaccine. First, the lack of a suitable animal model for MERS complicates the in vivo testing of candidate vaccines. Second, due to the low number of MERS cases, pharmaceutical companies have little incentive to pursue MERS vaccine production as the costs of clinical trials are high. In addition, the timeline from bench research to approved vaccine use is 10 years or longer. Using novel methods and cost-saving strategies, genetically engineered vaccines can be produced quickly and cost-effectively. Along with progress in MERS animal model development, these obstacles can be circumvented or at least mitigated.

Keywords:

• betacoronavirus
• Coronaviridae
• coronavirus
• MERS-CoV
• Middle East respiratory syndrome
• Nidovirales
• nidovirus

Financial & competing interests disclosure

The content of this publication does not necessarily reflect the views or policies of the US Department of Health and Human Services (DHHS) or of the institutions and companies affiliated with the authors. This work was supported, in part, by the US National Institute of Allergy and Infectious Diseases (NIAID) Division of Intramural Research, and in part through Battelle Memorial Institute’s prime contract with NIAID under Contract No. HHSN272200700016I. J Wada and L Bollinger performed this work as employees of Battelle Memorial Institute. Subcontractors to Battelle Memorial Institute who performed this work are as follows: JH Kuhn, an employee of Tunnell Government Services, Inc. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Key issues

• The control of emerging pathogen diseases is a perpetual challenge requiring constant re-evaluation and ingenuity in containment, treatment and prevention methods.

• The lack of a proper animal model for Middle East respiratory syndrome (MERS) is inhibiting the progress of vaccine testing. Animal models thus far have demonstrated limited pathology.

• The prediction of clinical trial success based on in vitro research results remains a major obstacle to timely vaccine development, particularly for vaccines against emerging diseases with high lethality as seen with MERS.

• Emerging pathogen control via accelerated on-demand vaccine development is an idealistic approach.

• The usual lag in disease identification from accurate clinical reporting of presentation and pathogenesis should be shortened, and the difficulties related to regulatory submission and licensure for vaccines should be addressed before on-demand methods can be practically implemented.

• Thus far, the most promising MERS vaccine candidates are those that are proven to elicit MERS coronavirus (MERS-CoV)-neutralizing antibodies and that use an approved platform for administration. These include vaccines by Novavax (MERS-CoV S nanoparticles) and Inovio Pharmaceuticals (DNA MERS vaccine targeting multiple antigens). MERS vaccines that focus on targeting the MERS-CoV receptor-binding domain also look promising.

Notes