The ‘Corona Viruses’ are the group of viruses that caused various infections in the late 2019 originated in Wuhan, China. The term Corona Virus is derived from a Latin word Corona which means “Crown” or “Wreath” which also means “Garland” in Greek. Electron microscopy demonstrated that they have a fringe of large bulbous projections mimicking the structure of crown.
The Corona Virus appears to be a large pleomorphic spherical particles with bulbous surface projections. The average diameter of the Virus is about 120nm (0.12µm). The diameter of the envelope is 80nm (0.08µm) and the spikes are 20nm (0.02µm)
The Corona Virus also called as SARS-CoV-2 consist of spherical particles having spikes protruding from the surface which latch into the human cells undergoing a structural change which allows the viral membrane to fuse with human cells membrane. The viral genes after entering the host gets copied to produce multiple viruses. Recent researches show that the SARS-CoV-2 spikes bind on the Angiotensin Converting Enzyme 2 (ACE 2). The viral envelope of the Corona Virus is consisted of a lipid bilayer where the Membrane, Envelope (E) & Spike (S) structural proteins are anchored. There is a Nucleocapsid inside the envelope which is formed from the multiple copies of the Nucleocapsid (N) protein which are bound to the positive sense single stranded RNA genome in a continuous beads on string type conformation.
Despite there are some similarities found in SARS 2002 and the SARS-CoV-2, the three different antibodies against SARS 2002 virus could not bind with the SARS-CoV-2. Thus the specific potential vaccine and the antibody based treatment for the SARS-CoV-02 have to be unique. Various researches are focusing on the vaccine candidates which can target the SARS-CoV-2 spike protein. The relation of the spike protein to isolate the antibodies from the people who have recovered from the infection of the novel corona virus can also turn useful for finding the antibody treatment against it.
COVID-19 VACCINE DEVELOPMENT
The genetic sequence of SARS-CoV-2 that causes COVID-19 was published on 11th January, 2020 which has triggered extensive global R&D activity for the vaccine development against the pandemic. There are various ongoing vaccine development processes to develop a potent vaccine against COVID-19. Following are some such developers of the vaccines against the corona virus.
China has approved three COVID-19 vaccines for clinical trials which includes an adenovirus vector vaccine which is developed by the Institute of Military Medicine under the academy of medical sciences. This was the first vaccine to enter the clinical trial. The first phase of the clinical trial of this vaccine was completed in March 2020 end and the second phase begun in April 12, 2020. According to World Health Organization (WHO), this has been the first vaccine to enter the second phase of the clinical trials.
- Entos Pharmaceuticals
Fusogenix DNA vaccine developed by Entos pharmaceuticals is the DNA based vaccine which will directly induce a plasmid for encoding the antigen. The use of plasmid DNA may enable advanced and potent method for encoding multiple protein epitopes from the SARS-CoV-2 proteins. The vaccine development is yet under process and after the development of the Fusogenix DNA vaccine, the company will begin with its preclinical testing.
- Pfizer and Biopharmaceutical New Technologies (BioNTech)
Pfizer under the collaboration with the Biopharmaceutical New Technologies (BioNTech) about to co-develop the potential COVID-19 vaccines. Under the collaboration agreement, these companies will co-develop and supply the m-RNA based corona virus vaccine against the COVID-19 infection. The companies have planned to advance the development of BNT162 which is first-in-class COVID-19 m-RNA based vaccine candidate which is expected to enter the clinical testing by the end of April 2020.
- Oxford University
Jenner Institute of the University of Oxford developed an adenovirus vector vaccine called ChAd Ox1 nCoV-19. The collaboration project between Jenner institute and the Oxford vaccine group opened the recruitment for the clinical trials at the end of March 2020 which initiated its research on the vaccine against the corona virus- borne disease COVID-19 in the February 2020.
Altimmune under the collaboration with the University of Alabama at Birmingham about to develop a single dose intranasal vaccine for COVID-19 named AdCOVID. The companies are carrying out the immunogenicity studies after which the vaccine will enter the phase I clinical trial. Altimmune and the University of Alabama at Birmingham working together to conduct the preclinical animal studies and the phase I clinical trial in the third quarter of 2020.
Inovio Pharmaceuticals under the collaboration agreement with the Beijing Advaccine Biotechnology company to progress towards the development of the former vaccine, INO-4800. The company has completed the design for the human clinical trials along with the ongoing preclinical trials. The results from the clinical study expected to be out in September 2020. The company’s vaccine development is currently in the phase I clinical trial.
- Modern & Vaccine Research Center
Modern and the Vaccine Research Center, a unit of the National Institute of Allery and Infectious Diseases (NIAID) to advance in the development of the vaccine which targets the spikes (S) proteins of the corona virus. The phase I human clinical trial begun on 16th March at the Kaiser Permanente Washington Health Research Institute in Seattle, Washington.
- MIGAL Research Institute
The MIGAL Research Institute in Israel publicized that the Avian Corona virus Infectious Bronchitis Virus (IBV) vaccine has been modified to treat COVID-19. The preclinical trials conducted by the Volcani Institute has demonstrated the efficacy of the vaccine in the preclinical trials. The institute also revealed that the IBV vaccine has greater similarity to the human corona virus. Further, they disclose that it may take next eight to ten weeks for obtaining necessary safety approvals for the in vivo testing.
- Clover Pharmaceuticals
Clover Pharmaceuticals is advancing towards the development of Recombinant Subunit Vaccine based on the S-protein (S) of corona virus which is causative for the viral infection by binding with the host cells. The company has successfully developed the subunit vaccine in mammalian cell culture based expression system by February 10, 2020. The company is also successful in identifying the antigen specific antibody in the serum of recovered patients. The company has disclosed that the vaccine may be available in an around six to eight weeks for the preclinical studies.
- Applied DNA Sciences and Takis Biotech
Applied DNA Sciences subsidiary LineaRx and Takis Biotech have been collaborated on February 07, 2020 to develop a linear DNA vaccine. The joint venture has planned to use Polymerase Chain Reaction (PCR) for the development of vaccine.
- Antibody Vaccines
|Gimsilumab||Roivant Science||Granulocyte macrophage colony|
|TIM2||I-Mab Biopharma||Granulocyte macrophage colony stimulating factor (GS-CSF)|
|TZLS-501||Tiziana Life Science||Human anti-interleukin-6-receptor (IL-6R)|
- Some other Examples of ongoing Corona Vaccine Projects
- Janssen (Johnson &Johnson group) with Biomedical Advanced Research and Development Authority (BARDA).
- Sanofi Pasteur also with BARDA.
- Zydus Cadila and Serum Institute in co-operation with US company Codagenix (India).
- Cambridge Infectious Diseases Research Center at University of Cambridge.
- US Army Medical Research and Development Command (USAMRDC).
- German Center for Infection Research (DZIF).
According to the data obtained on 8th April 2020, the global COVID-19 R & D Platform includes 115 vaccine candidates. From these, 78 are found to be confirmed as active and remaining 37 are unconfirmed i.e. their development status cannot be determined from publicly available information sources. Amongst the 78 active vaccine candidates, 73 currently in the Exploratory or Preclinical stages and the other advanced candidates have been recently moved in the clinical phase.
The global vaccine R & D efforts in the response to the COVID-19 is remarkable in respect to the speed. Thus this is denotive that the vaccines could be made available under the emergency or similar protocols by early 2021. This is the rudimentary step that changes the traditional vaccine development pathway i.e. over an around 10 years. Even though the R & D landscape be the imperative of speed, their unprecedented efforts cannot accomplish the entire vaccine development upto May 2020 including its safety and efficiency testing. Vaccine development is a long and complex process which usually takes around 10 years. Even if the accelerated timescale is followed as in the development of the first Ebola vaccine took 5 years for accomplishment. Thus vaccine development could not attain accomplishment upto May 2020, however symptomatic drug candidates can prove useful for the temporary treatments.