At this point of time at least 35 companies and academic institutions from all around the world are trying to develop a vaccine. The scientists started the race to find a cure soon after China shared the Sars-CoV-2 genetic sequence with the world in early January but as of now none of the researchers has found the success.

But recently the World Health Organization (WHO) has confirmed that two candidate vaccines for COVID-19 have entered the first phase of human clinical trials and another 60 candidate vaccines are currently in pre-clinical studies.

The promising Coronavirus vaccine candidates

CanSino Biological Inc and Beijing Institute of Biotechnology jointly developed the COVID-19 vaccine candidate. The researchers have used the non-replicating viral vector as the platform, same like the non-corona candidates such as Ebola, to develop a vaccine with an 'Adenovirus Type 5' candidate, a draft landscape of Coronavirus vaccine candidates brought out today.

Here it should be mentioned that adenoviruses are common viruses which cause pneumonia and can deliver potential antigens to stimulate the production of antibodies in the human body that works against the disease. It was in 2017 when CanSino Biological Inc along with the Chinese Academy of Military Medical Science's Bioengineering Institute had developed an Ebola vaccine.

However, the other candidate, which has entered the first phase of human trials is from the US-based biotech firm Moderna. The medical firm joined hands with the National Institute of Allergy and Infectious Diseases (NIAID) to develop this potential COVID-19 vaccine. This lipid nanoparticle (LNP) encapsulated mRNA candidate vaccine uses an RNA platform with multiple vaccine candidates.

As per the researchers, in terms of this kind of candidate vaccines, the virus's genetic information is decoded from the DNA to make proteins. The messenger RNA or mRNA acts as an intermediary between the genetic information in DNA and the amino acid sequence of proteins, which gives cells orders to generate proteins to fight against the viruses. But here the fact is such vaccines have not yet been approved to use on human.

It should be noted that as China looking for success in developing Coronavirus vaccine, the country said that it wants to carry out additional vaccine trials in other countries which are devastated by Coronavirus pandemic if the ongoing trial in Wuhan proves it is safe and effective.

China Human trial
COVID-19 vaccine trial (Representational picture) Pixabay

60 COVID-19 vaccines candidates

As mentioned by WHO, 60 vaccine candidates are in the pre-clinical trial stage. Earlier experts claimed that it will take 12 to 18 months before a vaccine is available. The pre-clinical stage includes testing in small and large animals, have to go through three phases of clinical trials to prove its safety and efficacy- which means lots of time should be invested to launch a safe and effective vaccine before commercial use.

These human trials are done on different population and in separate countries. The researchers behind these trials have to create huge data in the three phases of human trials for regulatory sanctions. But it is always possible that all these trial turn out to be failed attempts or only one in ten experimental vaccines make it all the way through to regulatory approval.

Can we expect a vaccine to be ready soon?

It has been a while people are asking the same question, "when a vaccine will be ready." Even though WHO delivered 'good news' it doesn't mean that any COVID-19 vaccine will be available for all the Coronavirus affected countries any time soon.

Here it should be noted that before the Coronavirus hit the world, scientists had no idea that the next outbreak would be caused by a Coronavirus, because of which the vaccinologists had hedged their bets by working on "prototype" pathogens. Richard Hatchett, CEO of the Oslo-based nonprofit the Coalition for Epidemic Preparedness Innovations (Cepi), "The speed with which we have [produced these candidates] builds very much on the investment in understanding how to develop vaccines for other Coronaviruses."

However, a vaccine for the Coronavirus will need to be put through especially stringent safety testing to rule out the risk of enhanced disease. For that reason, taking a vaccine candidate all the way to regulatory approval takes a lot of time. But there is another problem which cannot be overlooked.

Soon after the vaccine approval, it will be needed in each and every Coronavirus affected countries for millions of infected people. But many of the organisations who are working on Coronavirus vaccine don't have the necessary production capacity. It should be mentioned that Cepi plans to invest in developing a COVID-19 vaccine and boosting manufacturing capacity in parallel.