How are you doing? I hope you are at your best in this tough time.
This is the question that popped in my mind when I was seeing new strains of virus arising without ceasing for a bit. I thought this question may have come in many people’s mind, I mean this is one of the reason you are here.
Henceforth, let us hop into the discussion of knowing many questions like why there are lots of variations of coronavirus, and questions related to it such as:
- When it was first seen?
- Why there are lots of variations of coronavirus?
- Coronavirus structure
- Vaccine effect on mutated variants
- Should I take vaccine for newer variants?
But before jumping to that, let’s answer some other questions. Shall we?
When it was first scene?
It had been more than one and half year that the fast pace of the running world was put on halt by an unprecedented danger which has been seen once in a century and which, till this date still has the world in its grasp.
It was started as a small package in China, but later came out to be a global bombardment. Yes I am talking about Covid-19.
It was 1st seen in November, 2019, in Wuhan, a capital of Hubei province in China which outbursted and took over the largest of the economies. The disease is named as Covid19, as the discovering year, but it is 2021 now, and the cases are still brewing on despite of the treatments and preventive measures like vaccines. (You can read my next few articles if you want to know more about the vaccines and treatments.)
Now, back to our original question.
Why so many variations?
May be the medical system in the world is frail! Well, honestly I can’t deny that, as medical development is a never ending progress. And it takes time, effort and lots of medical experiences and knowledge to develop treatments according to that particular cause, here SARS-CoV-2 or Corona virus.
But here we are talking about one whole year to develop a SINGLE vaccine while the cases are burning up.
So, what could be the reason of this?
Well putting it simply. As we are taking measures to kill it or cure ourselves, the virus itself is taking counter measures to become ‘unkillable’.
So, a simple yet weird question one can ask- “Do they have consciousness about that?”
“So, how do they change or ‘mutate’?”
First keep in mind that it’s a chance event, hence not in someone’s own strength to mutate one self.
As we may have known that each living organism has some data of itself, more like its unique identity i.e. genomic material- either DNA or RNA. And for most of the organisms, it is the DNA as their hereditary material, which they pass to their next generation. However, virus can also have RNA and in our case, coronavirus ‘has’ RNA. Now if we are already here, why not let’s take a peek into its structure.
Coronavirus is a single stranded positive sense RNA virus (Question for you #1).
- Single strand is simple to understand as these viruses have only one strand of RNA.
- dsRNA examples of viruses are Hepatitis A virus, poliovirus etc.
- Positive sense means that RNA is similar to that of mRNA i.e. directly translated into viral protein particles inside the host cell cytoplasm.
- Whereas negative sense RNA also replicates in cytoplasm but at first the transcription must be done i.e. mRNA should form.
- RNA viruses, well, we can think of this much.
- This RNA and DNA classification is the most fundamental and important one.
- RNA viruses examples are mumps and measles virus (Paramyxoviridae),influenza virus (orthomyxoviridae).
- Whereas DNA viruses are HBV, HIV, HSV (herpes simplex virus) etc.
The RNA is enveloped by the protein coat, making up a virus. Other than these there are several beneficiary structures. One of such is spike protein (About#1).
A#1. Spike protein: It helps virus to enter into host cells by latching with angiotensin-converting enzyme 2, ACE2 (A#2).
A#2. ACE2– These are enzymes found on cell membranes of intestines, kidney, testis, gallbladder and heart. It converts Angtiotensin II to Angiotensin i.e. vasoconstrictor to vasodilator hence a beneficial drug to lower BP in cardiovascular disease.
Q#1. Do you know that coronavirus RNA is made up of 30,000 basepairs(bp)? So, what does this mean?
A#1. Imagine a very long line of human laying down head to toe to each other. Now think another line parallel to this one. Now, both of these lines, let’s say A and B, are joined by the corresponding humans, by joining/holding each other’s hand.
- Here, hand = bp and Human body = RNA backbone.
- Some of the humans belong to a same family = gene.
So, as the virus multiplies, the parent creates copies of its daughters.
The replication of genome is so fast that duplicating something this big is a miracle in itself. Keeping this in mind, once in a while there can be some variations in their gene sequence. These mutations most of the time, can cause the organism, here virus to become weak and hence can cause its own death. But sometimes, it turns out to be in favour of them like making it more transmissible.
Eg. Delta variant (B.1.617.2 carrying L452R, T478K and P681R mutations) which was 1st scene in India and later became the cause of 2nd wave of mass deaths, killing millions of people in India itself.
Delta variant, later, has further mutated into two more variants AY.1 and AY.2 known as Delta-plus variants, carrying spike protein (K417N) mutation which was also seen in B.1.351 or Beta variant first reported in South Africa.
Considering the above example in Q#1, suppose some of the members i.e. nucleotides (building blocks of RNA/DNA), of a same family i.e. gene, is substituted by somewhat other one. This can either break the chain of the complimentary functionality or enhance it.
And also, making the process somewhat different. So, making a different variant of the virus.
There were already alpha and beta variants detected where alpha being the 1st.
What makes the delta different is that, it is multi mutated in the gene coding for spike protein making it more dangerous.
So the vaccines will have any affect against the variants?
For this, 1st we need to understand what vaccines are. And while doing that we will be going to dive a little into our immune system.
Vaccines are of different types: For ex:
Inactivated vaccines: These consist of weakened viruses.
- This will not cause disease but will create an immune response. And here’s the thing comes. In our body, the 1st immune response is always weak and short lasting taking its sweet time to develop, which here is ignited by these weakened viruses already, before the 2nd infection.
- So, during the 2nd time, if the actual virus enters in our body, the 2nd response will be a robust one with fast and strong response and for longer duration. It happens because of memory cells, but leave it for later.
- Eg. Covaxin, developed by Bharat Biotech and Indian Council of Medical Research.
Viral-vectored vaccines: In these, a vector carries the antigen.
- Means, a safe virus is used to carry the immune producing antigen to impart an immune response.
- The immunity will still think of it as a threat but as the virus is non-pathogenic, the symptoms will not be there.
- Eg. Covishield which is made from chimpanzee viral vector with weakened version of common cold virus, developed by AstraZeneca and Oxford University whilst in India is manufactured by Serum Institute of India (SII).
There are more types but we will be going superficially through them. They are
- Protein based vaccines, containing only the antigenic fragments without the virus itself.
- Nucleic acid vaccines(DNA or RNA), these are vaccines using genetic material of the pathogenic organism that stimulates the immune response.
- Popular known mRNA vaccines are Pfizer and Moderna.
So, the answer to our question.
We will understand it by taking an example.
It has been seen that the vaccines for the B.1.617.2 are actually less efficient as the antibodies formed in the body were less able to neutralize the virus.
So it’s both yes and no.
Yes, as it might still work on the virus as the response generated in the body is a diverse one (It means that our body has many kinds of soldiers protecting the body).
No because it will be less efficient.
So the question arises now: Should I take vaccine now as for the newer variations?
The answer in short is ‘Yes’.
Definitely a yes. It is true that the vaccines are less effective on the newer variations. But it doesn’t mean that the original one has been eradicated entirely from the world. Also, it might not cease the symptoms but can prevent the death though.
The research is endlessly going on. As the new variants are coming, the vaccines will be modified too. We can say that- But will the virus will mutate too and creating an endless cycle.
That is true indeed, but keep in mind, sometimes ago, Polio and Tetanus were fatal too yet they are not talked about now thanks to the very vaccines.
I hope my attempt to answer your curiosity is successful. There will be many articles on covid and other related topics. Be sure to read them too.
Don’t forget to give me feedback and ask any question in the comment box.