New Experimental Vaccine Produces Immune Response Against MERS

The University of Maryland School of Medicine and Novavax, Inc. announce that an investigational vaccine candidate developed by Novavax against the recently emerged Middle East Respiratory Syndrome Coronavirus (MERS-CoV) blocked infection in laboratory studies. UM SOM and Novavax also reported that a vaccine candidate against Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) developed by Novavax on a similar platform also inhibited virus infection. Researchers reported these findings in an article published in the April 13, 2014 issue of Vaccine.(1)

Historically, vaccine strategies for emerging pathogens have been limited due to the sudden nature in which the virus first appears and delayed by the protracted traditional vaccine development process. This peer-reviewed manuscript describes a novel method to rapidly develop vaccines against previously unknown viruses, such as MERS-CoV, which appear suddenly and cause severe illnesses in humans. The experimental vaccines, which were tested in conjunction with Novavax' proprietary adjuvant Matrix-M™, induced neutralizing antibodies, or immune responses, that prevent viruses from infecting cells.

"Our protein nanoparticle vaccine technology is proving to have the potential to respond rapidly to emerging viruses such as MERS-CoV and certain potential pandemic influenza strains, addressing what are clearly urgent public health needs," says Gale Smith, PhD, vice president of vaccine development at Novavax. "Novavax will continue to evaluate this technology to produce highly immunogenic nanoparticles for coronavirus, influenza, and other human disease pathogens with the potential for pandemic and sustained human to human transmission."

"The emergence of SARS-CoV and MERS-CoV demonstrates how coronaviruses can spillover from animals into humans at any time, causing lethal disease," says Matthew B. Frieman, PhD, assistant professor of microbiology and immunology at the University of Maryland School of Medicine and corresponding author on the publication. "Despite efforts to create a vaccine against SARS-CoV, no vaccine candidate has, to date, been successfully licensed for use. We have demonstrated that this novel method rapidly creates SARS-CoV and MERS-CoV vaccines that induce neutralizing antibodies in mice."

"The University of Maryland School of Medicine investigators are continually working toward a better understanding of the interactions between the human immune system and a variety of known and novel harmful microbes," says E. Albert Reece, vice president of medical affairs at the University of Maryland and the John Z. and Akiko Bowers Distinguished Professor and Dean for the University of Maryland School of Medicine. "This makes our faculty poised to respond to emerging infectious diseases, such as MERS-CoV, which threaten the health and wellbeing of the global population."

The vaccine candidates were made using Novavax' recombinant nanoparticle vaccine technology and based on the major surface spike (S) protein, a SARS-CoV and MERS-CoV surface protein responsible for attaching the virus to cells. Novavax previously demonstrated that spike protein nanoparticles could protect animals against lethal live challenge using the SARS-CoV virus.(2)

MERS-CoV, first identified in 2012, is one of a family of viruses with the potential to rapidly spread from a benign infection of animals to cause severe disease in humans. In 2003, a previously unknown coronavirus called SARS-CoV caused an outbreak that raised health alarms by infecting more than 8,000 individuals and killing 775. According to the World Health Organization, the novel MERS-CoV thus far has resulted in 107 deaths out of 345 infections, the majority of which are characterized by severe illness and hospitalizations. Both diseases were marked by a jump from animals to people and while SARS-CoV spread more quickly in humans, MERS-CoV is proving to be more deadly.

Source: University of Maryland School of Medicine, Novavax, Inc.

References:

1. C. M. Coleman et al. Purified coronavirus Spike protein nanoparticles induce coronavirus neutralizing antibodies in mice. Vaccine. In press, April 13, 2014.

2. Y. Liu et al. Chimeric severe acute respiratory syndrome coronavirus (SARS-CoV) S glycoprotein and influenza matrix 1 efficiently form virus-like particles (VLPs) that protect mice against challenge with SARS-CoV, 2011; 29(38): 6606-6613.