HKU State Key Laboratory for Emerging Infectious Diseases joins global effort to develop COVID-19 vaccine

The State Key Laboratory for Emerging Infectious Diseases of the University of Hong Kong (the SKL) has partnered with the Coalition for Epidemic Preparedness Innovations (CEPI) to rapidly develop a vaccine candidate against COVID-19.

Launched at Davos in 2017, CEPI is a partnership between public, private, philanthropic, and civil organisations to develop vaccines to stop future epidemics. The SKL, which was established in 2005 and co-directed by Professor K.Y. Yuen of the Department of Microbiology, has played a key role in supporting Hong Kong SAR in response to several outbreaks of infectious diseases including the current COVID-19.

The HKU team led by Professor Honglin Chen, along with team members Professor Zhiwei Chen, Professor Yiwu He and Professor Kwok-Yung Yuen, is the latest team globally to join CEPI for development of a vaccine for COVID-19. Currently there are seven COVID-19 vaccines in development by different expert teams in the world.

President and Vice-Chancellor of HKU Professor Xiang Zhang said: “I’m thankful for the support from CEPI. The University of Hong Kong has outstanding researchers in emerging infectious diseases. I’m hopeful the vaccine being developed in our labs will contribute to the containment of COVID-19.”

Dr. Richard Hatchett, CEO of CEPI, said: “Be under no illusion – vaccine development is tough. It is complex and costly but CEPI was set-up specifically to overcome these challenges to rapidly develop vaccines against emerging infectious threats like the COVID-19 virus. There are no guarantees of success, but we are working flat out and hope to deliver safe and effective vaccine perhaps within the next 12-18 months.”

The outbreak of SARS-CoV2, first emerged in Wuhan China in December 2019, has led to the first documented coronavirus pandemic in human history as declared by World Health Organization (WHO). Up to now, more than 180 thousand confirmed cases have been reported globally. The impact on human health, societal stability and economic development is clear and significant, and the outcome of this pandemic is still unpredictable.

There is concern that SARS-CoV2 may become more adapt to humans and evolve into a human virus, leading to long term prevalence in humans.  Vaccination is considered the most effective way to block an outbreak and to alleviate the disease burden and mortality associated with infection and curb future pandemics.

In response to the outbreak of SARS-CoV2, researchers at HKU have made a vaccine candidate based on the established flu-based DelNS1 live attenuated influenza virus (LAIV) platform. This vaccine candidate has several unique properties:

• It is a flu-based vaccine and can combine with any seasonal flu vaccine strains.
• It is live attenuated with the deletion of the key virulent element and immune antagonist, NS1, from the viral genome and potentially be more immunogenic than wild type influenza virus.
• It can be produced in chicken embryonated eggs and MDCK cells which are proven production systems for influenza vaccines.
• It uses flu vector to express a specific antigen to induce immunity targeting the critical element of the Receptor Binding Domain (RBD) of SARS-CoVs. Such strategy may avoid potential antibody dependent enhancement (ADE) as observed in the experimental vaccine for SARS-CoV.
• It can be used as nasal spray.

HKU researchers have previously completed a proof-of-concept study testing this flu-based RBD vaccine system using a MERS-CoV animal infection model and found that vaccination with DelNS1-MERS-RBD LAIV provides full protection from a lethal challenge of pathogenic MERS-CoV. The team is currently conducting similar proof of concept studies in multiple animal models.

This vaccine strategy has been selected as one of the five vaccine technologies by the Ministry of Science and Technology of China for further evaluation. Collaborations with Xiamen University, and industrial partners including Changchun-Baike, Hualan-Bio, Beijing Wantai, Sinovac and CNBG on Mainland China have been set up to test the production of DelNS1-SARS-CoV2-RBD LAIV from eggs and MDCK cells respectively.

In the current collaboration with CEPI, a US$620,000 seed funding support has been awarded to conduct studies in evaluating the effectiveness of DelNS1-SARS-CoV2-RBD LAIV in the containment of the SARC-CoV2 pandemic.