लोकपाटी न्यूजHere’s a delightful video presentation of the methods currently being used for the production of the vaccine of Covid 19.
This fatality rate of Covid 19 is 5 to 17 times smaller than the previous two CoronaVirus outbreaks that hit humas hard- the SARS CoronaVirus in 2003 and the MERS CoronaVirus in 2012. This number on its own, might give a false impression that we are dealing with something relatively less dangerous in Covid 19. In terms of the fatality rate, yes. In terms of The Basic Reproduction Number – NO. The Basic reproduction number gives us a measure of how many healthy people one person affected with a virus is likely to transmit the virus to. In the case of MERS CoronaVirus, this number was 0.3-0.8. When Basic Reproduction Rate is less than one, as was in the case of MERS, it means that from 10 people with the virus, it was likely to get transmitted to only 3 – 8 people. And these 3 -8 people were only likely to transmit it to 1-4 people, and so on. But in the case of Covid 19, one infected person is likely to transmit it to 2-7 people, who are then likely to transmit it to a greater and greater number of people. This unprecedented rate of transmission is one of the reasons why even countries such as Italy are forced into a quarantine.
So what really are the odds of getting a vaccine for CoronaVirus? Well, getting a vaccine for any virus- no matter how innocuous it is- is a difficult prospect. This is because a virus changes its genetic configuration in a blink of an eye in comparison to mutation observed in human beings. In human beings, a mutation can be seen in a generation i.e. after human beings bear offsprings, who bear traces of mutations, which takes a few decades. In the case of Covid 19- which hit us in November- it has already mutated into S and L types in a matter of a couple of months.
So while developing a vaccine, scientists need to make sure that a vaccine can handle such mutations or else the virus can change its make up in such a way that it is practically immune to vaccines. This is one of the reasons why we need to get a different flu shot each year. The flu virus changes its genetic makeup to counteract the shot so that after one year the virus is immune to it and therefore a new shot has to be taken which counteracts the changes made by the flu. But predicting such mutations is a difficult thing. This is because a Virus is made up of either RNA or DNA, which is an arrangement of a staggering number molecules in a particular manner. As the arrangement of molecules of the RNA of CoronaVirus integrates with our own DNA and RNA, which has billions of possible combinations. This makes nailing these possibilities and predicting how a virus is likely to change its shape and that of our DNA or RNA the most challenging of prospects while creating a vaccine.
A few medications have been tried to fight Corona. A cocktail of lopinavir and ritonavir, which are used to lower HIV levels in our blood stream, was served to a person in Thailand. 48 hours after its consumption, the Covid19 infected infected person tested negative. This was an isolated case and certainly not a case of a vaccine.
One of the methods that is currently being tried for the development of a vaccine is to make a dummy of the Covid 19 virus inside the body of human beings. This is done with the help of mRNA synthesized in the laboratory. Normally, mRNA’s inside our bodies transmit the instructions contained within our DNA. But the synthesized mRNA is being programmed to get our body to produce certain CoronaVirus like bodies. When such proteins develop inside our bodies, scientists hope that our immune system will recognize them as foreign bodies and learn how to fight them as antibodies. So when the real, instead of the laboratory made doppelganger of CoronaVirus, does get inside our body, our immune system will have had enough of a response system to fight it off.
Another strategy being used for producing a vaccine is maintaining the stability and configuration of spike protein of CoronaVirus. The surface of CoronaVirus has a lot of proteins which gives it a crown like structure- hence the name Corona. Researchers are working on synthesizing amino acid sequences in a laboratory such that when it is inserted into spike protein of CoronaVirus, they bind perfectly with each other. This produces a greater stabilization of the spike and may help our body provoke accurate immune response.
But before such vaccines are tried in human beings, conventionally, such tests are performed in laboratories in animals such as mice. But the Covid19 doesn’t seem to thrive in mice cells making such tests difficult to run. Besides, another problem is the possibility that whatever short term plans we take to mitigate its effects, the virus might evolve differently in other animals such as bats, and manifest itself as a different strain some later time. Historically, creating vaccines for viruses have taken somewhere between half a decade to a few decades. But historically, we have never seen a virus take over the globe so quickly. The positive side in all of this is that never in our history have we had as many resources, scientifically or economically, to counteract a virus. So it will be interesting to see further developments in the making of the vaccine of CoronaVirus. The best estimates, at least for now, have it that middle of 2021 would be the earliest that a vaccine might be available.
