Vaccine against Virus !

When will everything be normal? When all this is going to end? These are few of the most discussed and searched topics these days. Finding a cure to the disease may well end all these things. But isn't prevention better than cure? For the infectious diseases like COVID-19, if we wish to continue our routine life then vaccine is the most effective way of prevention. So today entire mankind, in an unprecedented manner, is united for one single challenge of developing a vaccine against COVID-19. 

By now we all know that SARS-Cov-2, the virus causing COVID-19 is a novel type of corona virus. Earlier outbreaks of SARS, MERS were also caused by corona virus only. So if the vaccines for these diseases were in place by now, scientists believe that we would have been in much better position today and would have developed the vaccine against COVID-19 in very short span of time owing to the similar nature of the virus. In fact some of the companies like Inovio along with CEPI (Coalition for Epidemic Preparedness Innovations) had developed the vaccine in epidemic-speed and even started the human trials. But when these outbreaks-fortunately- sputtered out, the funding and interest in development of vaccine waned. 

Stages of development of vaccines. Source: sciencedirect.com

But despite all the odds today around 115 COVID-19 vaccines are in development at different stages.

Roughly speaking there are 7 stages before actual use of vaccine at mass scale. These stages include- discovery & exploratory stage (laboratory R&D), preclinical stage (involves testing on the animals), phase-1 (testing the vaccines on dozens of humans), phase-2 (testing on around hundreds of humans), phase-3 (testing on around thousands of humans), regulatory approval and finally manufacturing & launch of the vaccine.  

Type, Variant and Manufacturing capacity: The triad of vaccine development

There are different types of the vaccines. Some of the important ones are as follows:

1. Live vaccines : in which the pathogen is induced in "attenuated" form. When the body detects this 'antigen', immune system of body develops its own 'antibodies' to fight against these antigens. Now this antigen is kept in its memory by the body and whenever actual pathogen attacks the body, memory system triggers the antibody response.

2. Inactivated vaccines : These vaccines work on similar principal as above, only difference is that they contain the killed pathogens instead of attenuated ones. 

3. RNA vaccine- RNA & DNA vaccines are the future of vaccines. Instead of injecting the pathogen's antigen directly into the body, RNA vaccines induce the genetic code needed to produce the antigen itself in human body. When antigens appear on the outside of the cell, body's immune system attacks them and also learns how to fight future intruders of such types. Therefore by this process, human body itself becomes vaccine manufacturing unit. 

Distribution of ongoing vaccine development projects for COVID-19.
Source: CEPI

WHO, many scientists, businessmen and philanthropists like Bill Gates are championing the cause for RNA based vaccine. This is because RNA vaccines are easier, faster and safer to manufacture unlike the traditional vaccines which require much of the biological material for production. But the risk involved is that world has never ever launched RNA vaccine in its final stage yet. Though research and some trials of RNA vaccines are conducted earlier but final mass production after successful trials has never happened.

Apart from the type of vaccine, second catch is of the variant of vaccine depending upon the method of administering the vaccine. This includes oral vaccine, intra-dermal  vaccines (injected into the top layers of skin), muscular vaccines (injected into the muscles). For COVID-19 we need the vaccines which can be administered easily because this vaccine will be required for entire 7 billion population of the world. At such a large scale, the faster and easily deliverable vaccines are important. Companies like Bharat Biotech are developing a vaccine named 'Coroflu', which will be a nasal vaccine to be administered through the nose. They are collaborating with University of Wisconsin. Whereas ChAdOx-1 developed by Oxford University is intra-dermal vaccine and currently at the stage of human trials.

Now next question is by when we will get the vaccine ready at mass scale. What we have discussed till now focuses mostly on the R&D of the vaccine. But the very important and complex stage comes after that, the stage of manufacturing. For 7 billion vaccine doses, we will require minimum 7 billion vials and equal number of stoppers. And suppose if vaccine requires double dose, then we need 14 billion of these components. Also the vaccines require specific conditions for storage like specific temperature etc. After manufacturing, the supply chain management and logistical issues like proper transport of all these vaccine doses to desired places is also a challenge in itself. Each kind of vaccine requires its own kind of factory for manufacturing. as we don't know yet which type of vaccine will play out successfully, it is difficult to build desired factories also. But still Indian manufacturers like Serum Institute have already began setup for ChAdOx-1 vaccine developed by Oxford university and will start manufacturing once the successful results of vaccine are received. Also Bill&Melinda Gates Foundation have declared to keep 7 factories ready for 7 different types of vaccines even before these vaccines are established to be successful to reduce the time for manufacturing in the future. This is the real bet for humanity all of them are taking. 

Who should get it? 

One of the final but very important issue we must discuss is who will get the vaccine first. Considering the huge and unprecedented demand for the vaccine across the world and considering the phased manufacture of vaccine, question of prioritizing the distribution might arise. This is a very difficult question and a kind of ethical dilemma. Should it be given to elderly persons first considering the higher risk they face or should it be given to health workers first who have direct exposure to the disease? Or should the developing and manufacturing countries should have the first right on the vaccine? Countries across the world have closed their borders today. Except few noble examples like that of India, which is helping other countries in such difficult times, the game of name & shame is in full fledge amongst different countries. But to address this question of 'who should get the vaccine', we need the global cooperation and collaboration like never before. The equitable distribution strategy must be decided by all.

Strong global partnership between governments across the world, research laboratories, manufacturers, funders, national health regulators of all the countries is the need of the hour. Being a global leader in manufacturing the vaccines, India has potentially the huge role in saving the fate of humanity. With all the efforts in right direction, lets hope for speedy & pandemic-speed vaccine sooner at the end of the tunnel.

Sources : - 

-CEPI (Coalition for epidemic preparedness Innovations)

- GAVI, the public private Vaccine Alliance

- Talks by Bill Gates

- Oxford University.