With the disastrous epidemic status of coronavirus (COVID-19) in several parts of the world, the need of the hour is an urgent coronavirus vaccine development to prevent the spread of this virus and reduce the global mortality numbers which have gone up to 3283, according to WHO situation report 45. The elderly and sick people are the most affected lot in the world population and the deaths are mostly due to the weakening of their immune system. In such a scenario, vaccine effects are also affected but research has shown that cell-based vaccines can reverse the weak immune system trend and make the vaccination more effective. This concept can be taken up to combat the coronavirus outbreak and develop cell-based vaccines for the same.
What is a Cell-based vaccine?
Cell-based flu vaccines use cell-grown candidate vaccine viruses (CVVs) that have the potential to offer better protection and efficacy than traditional flu vaccines as a result of being closer to mimicking circulating flu viruses. The cell-based vaccine manufacturing process uses primary cells in culture medium as a host for the growing virus. This cell-based production process for flu vaccines was FDA-approved in 2012 and has been widely used for making inactivated flu vaccines.
How are Cell-based vaccines prepared?
Cell-based flu vaccines started with egg-based vaccines and what started with chicken eggs, was replaced by human eggs. The flu virus is firstly grown in primary cells to create CVVs and then these CVVs are provided to a vaccine production research lab. After that, these CVVs are transfected into mammalian primary cell culture and allowed to replicate for a few days. The media is then collected for secretome analysis and the virus antigen is purified and tested. This purification step continues for some phases and finally, the vaccines are tested and certified for public use. This cell-based technology has the potential to boost the vaccine manufacture process and enhance its effectiveness manifold.
Advantages of Cell-based vaccines?
The main advantage of mammalian cell-based vaccines is the potential to produce fast vaccine supplies and therefore is quite important in times of an epidemic like coronavirus disease, which is soon going to attain a pandemic status. Furthermore, mammalian cell-based viral antigen production offers a faster and more stable vaccine production compared to traditional chicken egg-based vaccine production.
Are Cell-based vaccines in-process for COVID-19?
Recently, scientists have discovered potential targets for vaccines in the novel coronavirus structure and these targets can be exploited by researchers to design cell-based vaccines. According to another research, X-ray crystallography structure has indicated a series of α-ketoamide compounds that would bind and block active sites in coronavirus. These compounds were further tested in vitro using human primary cell culture. Some companies have also come forward to collaborate with announcements of successful pre-clinical animal trials using COVID-19 vaccine candidates. To be certain of cell-based vaccine production for COVD-19, researchers have to decode the structural and functional characteristics of this new strain fundamentally. Although SARS-CoV and MERS-CoV characteristics have been worked on, previously during 2003 and 2012 outbreaks of coronavirus, COVD-19 vaccine studies are still on-going. Therefore, although cell-based vaccines are obviously in process, there is no immediate guarantee of coming up with a cell-based COVID-19 vaccine.
The director of the National Institute of Allergy and Infectious Diseases has announced, “It will take at least a year and a half to have a vaccine we can use.” This, if possible, will be a record in the field of vaccine production as efficient vaccine production takes much more time than that due to various limitations and stringency. But to prevent the further spread of COVD-19, the world is eagerly waiting for this hope to materialize.