GAITHERSBURG, Md. and PHILADELPHIA—The University of Maryland School of Medicine (UM SOM) and Novavax, Inc. today announced 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.
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.
"The emergence of SARS-CoV and MERS-CoV demonstrates how coronaviruses can spillover from animals into humans at any time, causing lethal disease," said Matthew B. Frieman, Ph.D., 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."
"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," said Gale Smith, Ph.D., 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 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," said E. Albert Reece, vice president of medical affairs, the University of Maryland and the John Z. and Akiko Bowers Distinguished Professor and Dean, 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.
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, SARS-CoV, caused an outbreak that raised health alarms by infecting over 8,000 individuals and killing 775. According to the World Health Organization (WHO), 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.
Meanwhile, Hemispherx Biopharma announced that one of its advanced stage biological products, Alferon N, significantly inhibited the replication of the MERS virus in-vitro. Recent testing in laboratories of the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, revealed that Alferon N was inhibitory to MERS-CoV both when used before test cells were exposed to MERS-CoV, as well as after the cells were exposed to the deadly virus.
NIAID researchers led the Alferon N MERS-CoV experiments. They treated monkey kidney cells with Alferon(R) N either 18 hours prior to infection with MERS-CoV ("pre-treatment") or 1 hour following infection with MERS-CoV ("post-treatment"). At Day 1 and Day 3, supernatants were collected from cells and virus titers were measured. In both cases, Alferon N showed significant dose-dependent inhibitory effects, thus suggesting the potential of Alferon N both as a preventive and a potential treatment. The press release announcing the results noted that in-vitro laboratory studies of potential antiviral agents are not necessarily predictive of clinical benefits. The company was not involved in the conduct of the experimentation. The results were forwarded to Hemispherx at the conclusion of the experiments and formal publication is pending.
Juergen Richt, DVM, Ph.D., Regents Distinguished Professor at Kansas State University, stated "This is encouraging news. Non-human primate animal model testing of Alferon may give us more definitive data about the efficacy of this natural interferon against MERS."
The deadly MERS disease, originally identified in the Middle East, has recently claimed its first victims in Southeast Asia killing a Malaysian man who returned from pilgrimage in Saudi Arabia, according to WHO as reported in the WSJ on April 18, 2014. Although this did not happen during the past hajj, infectious disease specialists have been concerned that the illness could spread far afield by the millions of pilgrims who come to the Saudi holy city of Mecca each year for the Muslim pilgrimage. Most of the identified cases have been in Saudi Arabia although increasing numbers are being reported in the Gulf countries. Europe has reported a handful of cases, all with links to the Middle East. The U.S. has just reported its first case of MERS. MERS has been estimated to kill about one-fourth of the people it infects, largely through respiratory infections. The MERS-CoV replicates in camels which may serve as an animal reservoir for the virus. About half of the current cases have involved health workers. Alferon N has been demonstrated previously to be active against SARS-CoV (Emerging Infectious Disease, Vol. 10, No. 4, April 2004), a closely related human coronavirus responsible for the deadly SARS pandemic.
