Covid-19 vaccine: Why the world is developing 165 vaccine candidates? Here are the reasons

With many vaccines slated to appear late on the horizon, the imperfections and lacunae found in the early vaccines could be weeded out.

According to the latest information released by the World Health Organisation (WHO), the number of vaccine candidates against Coronavirus has increased to a total of 165 across different parts and countries of the world. There might be many more attempts going on at the same time but the WHO has listed only these 165 as they have at least entered the pre-clinical stage, the Indian Express reported. While some of the vaccines have entered the clinical phase 3 trials and leading the race many others are only at the animal trial stage and may take a couple of years to actually fructify into a successful vaccine. One would naturally wonder why the world is developing so many vaccines and draining its precious resources and duplicating efforts by developing over 165 vaccines for the same disease. On the other side, it could also be argued that we could get a foolproof vaccine earlier if all the countries and health organisations joined the forces and produce it on a mass scale.

Vaccine development: Low success rate
The vaccine development against Coronavirus has got unprecedented attention and spotlight which is unparalleled in the history of medical science with all people of the world waiting for a positive result with equal desperation. However, the process of vaccine development has always been slow, time consuming and full with uncertainty. The success rate of vaccine candidates is very low as they need to cross different stages of animal and human trials successfully. On an average, out of the 100 candidates in the research lab, only 20 are deemed fit to be tried on animals. The fight becomes narrower as only 4-5 candidates prove successful during animal trials and enter into the clinical trial stage. Subsequently, out of the lot only 1-2 candidates win the final battle and are ready to be used on large populations. Presently, out of the 165 candidates, only 23 have been able to reach the clinical trial stage out of the lot while others are still at the pre-clinical trial stage, according to the WHO.

The hype around the top vaccine candidates like University of Oxford’s or US’s Modernica getting ready in a matter of months also belies the reality as even they are not guaranteed to succeed and might show adverse results during phase 3 human trials. In comparison to earlier phases of clinical trials, the phase 3 of human trials is considered the toughest as volunteers are administered the vaccine outside the laboratory conditions. To sum it up, out of the 165 candidates only a handful of vaccines are going to succeed and not hundreds of them.

More vaccines vital for meeting universal demand
Even before any of the vaccine candidates could pass all the phases of clinical trials, the top and rich nations of the world striked deals with their manufacturers for early dispatch of the medicine. This has raised concerns over the possibility of inequitable access to the vaccine. While countries like the United States have already booked millions of doses of different vaccine candidates, the developing countries of the world might be staring at a long wait before they get their hands on the vaccine. This is the reason why countries like Argentina, Thailand, and Egypt, who have not covered themselves in glory on the medical front, have also entered the race of Covid-19 vaccine as they might succeed later than their contemporaries but the access and production of the vaccine will rest within their control.

Moreover, the vaccine which first emerges successful is not destined to be the most effective and successful in controlling the spread of the virus. With many vaccines slated to appear late on the horizon, the imperfections and lacunae found in the early vaccines could be weeded out.

Vaccines development via different technologies
Not all vaccine candidates are being developed by the same technology. Technologies like RNA and DNA which have never been successful in producing a vaccine in the past, are also being used to develop the vaccines for Coronavirus as they could be developed quickly in less time. In these technologies, the DNA of the virus is injected into the human body to stimulate a response against the infection. In contrast, the traditional approaches of developing a vaccine, scientists inject weakened forms of the virus itself in the body to evince a response against the disease.

Fund availability
In normal times, securing funds for vaccine development is one of the toughest tasks for the brethren of scientists and pharma companies. However, with Covid-19 wreaking havoc on all the world economies and draining hard earned wealth of decades, most countries, health bodies and non government organisations have loosened the string of their purse to ensure that every potential vaccine candidate does not get deprived of the funds.