COVID 19- VARIANTS AND VACCINES:

6 min


Firstly, the term ‘COVID-19′ needs no explanation in today’s world. Most of us would have been pretty unaware of this before 2 years. Today, it has become a global pandemic and is haunting us. COVID stands for Coronavirus disease (formerly known as 2019 novel coronavirus or 2019-nCoV).

It began as a group of pneumonia cases in Wuhan of China. Consequently, it was Covid -19. Some of these people reported working in seafood and animal markets. This later spread within China and to the rest of the world. Later, the WHO announced this as a public health emergency of international concern on January 30th, 2020.

ORIGIN AND STRUCTURE OF THE COVID-19 VIRUS:

The term corona is derived from a Latin word meaning crown. It denotes the resemblance of the virus to a crown. Further, coronaviruses are a large group of viruses. It contains a core made up of genetic material surrounded by a lipid envelope. Protein spikes are present in the outer layer.

There are different types of corona virus that can cause illness in animals and humans.

Further, in humans, it manifests as a respiratory illness. The symptoms range from the common cold to more severe forms. The severe forms include

SYMPTOMS OF COVID-19:

The symptoms of this disease appears 2-14 days after exposure to the virus. These include,

  • Chills
  • Cough
  • Cold
  • Fever
  • Fatigue
  • Muscle or body pain
  • Headache
  • Shortness of breath
  • Loss of taste or sensation of smell
  • Running or congested nose
  • Diarrhea
  • Nausea or vomiting

Some of the symptoms or a combination of the above symptoms may be present.

VARIANTS OF COVID 19:

It is a major concern with viruses. A variant is nothing but a mutation that occurs in virus over time. So as the virus affects people it has an opportunity to replicate it’s genome. With every replication, there are chances for mutations to occur.

In order to understand the variants, we need to know about the common corona virus which is the D614G. The mutations in the spike protein are the major causes of the virulence of the virus. This increases the entry of the virus into the cell or particularly evade the immune system.

There are 3 primary variants,

  • 1st one is the United Kingdom variant ( B.1.1.7)- very common
  • 2nd one from South Africa (B.1.1351)
  • The 3rd one was in Brazil (P.1)

WHY IS VARIATIONS A MAJOR CONCERN:

As we already read, mutations cause the variants. Further, these mutations in a cell increase viral entry which increases the viral replication in turn increasing viral production and transmission of the virus. The viral load increases in the person’s body. As a result, transmission becomes easier and we may spread it easily.

The United Kingdom variant :

It has a higher potential for transmission. It spreads faster and the disease process is fast.

  • Mutation- N501Y. (Responsible for transmission)
  • Deletion of the amino acid- HV 69/70 (Responsible for evasion of neutalising antibodies)
  • Substitution occurs at P618H amino acid (Increase viral entry)

However, it causes mild to moderate symptoms and doesn’t require prolonged hospitalization.

The South African variant:

The South African variant can also spread faster but like the UK variant, this doesn’t require prolonged hospitalization. The difference between the UK variant and the South African one is the substitution of the amino acid. Here it is at the level of E484K. Like we already saw substitution increases viral entry hence increasing transmission.

The Brazil variant:

P.1 or Brazil variant is still under research.

COVID- 19 VACCINES :

INDIA:

Currently in India 2 types of vaccines are available for the public. Namely,

  • The Covishield
  • The Covaxin

The route of administration for both these vaccines remains the same. Besides, it is an intra-muscular injection given in the deltoid muscle.

The dosage is 0.5 ml each, given as 2 separate doses.

Covishield vaccine:

Covishield normally is a type of vaccine that implies a technology wherein a normal non-severe form of adenovirus group category commonly from chimpanzees is taken. It is based on a viral vector platform. The vector that is modified to carry the coronavirus is the ChAdOx1. This is slightly modified to have characters like the coronavirus. This is incorporated into the vaccine at a safe dose. Subsequently, this vaccine when introduced into the human body is identified as the covid virus. Antibodies develop an immune response against it.

The Institute of serology in Pune manufactures the vaccine.

Further, this vaccine has been relatively efficacious. After the 1st dose of the vaccine, the efficiency was 70%. Further, with the 2nd round of the vaccine, there was almost 90% of immunity against the virus.

INGREDIENTS OF COVISHIELD:

  • L-histidine
  • L-histidine hydrochloride monohydrate
  • Disodium edetate dihydrate (EDTA)
  • Magnesium chloride hexahydrate
  • Polysorbate 80
  • Ethanol
  • Sucrose
  • Sodium chloride
  • Water for the injection

Covaxin:

Yet another vaccine is Covaxin. Bharath biotech in collaboration with ICMR and the National institute of Virology developed this vaccine.

Meanwhile, the method used in the manufacture of this virus is pretty common and has been used in the development a lot of other vaccines.

That is to say, a live covid virus is taken. However, it is ensured that the virus is killed completely and is safe. The skeletal structure of the virus or the outermost capsule of the virus is inoculated into our body. Further, when this is given as a vaccine to our body, our system identifies it as a covid virus and produces antibodies that develop immunity against coronavirus.

Also known as whole virion inactivated vero cell technology.

Above all, covaxin has a 81% efficacy.

COMPOSITION OF COVAXIN:

The covaxin contains the following components,

  • 6 micrograms of the whole virion inactivated SARS CoV 2 antigen
  • Aluminum hydroxide gel
  • Imidazoquinalinone -15 micrograms
  • 2-phenoxyethanol 2.5 mg.
  • Phosphate buffer saline up to 0.5 mL.
  • Inactivated killed virus along with the above-mentioned components.

In addition, both these vaccines are available in India to the general public. They are relatively safe.

However, people taking these vaccines may experience certain side effects. Some of them include,

  • Pain, swelling, itchiness at the local site of the injection, after administration of the vaccine
  • Redness
  • An uneasy sense of fatigue
  • Soreness, stiffness, weakness of the arms where the injection was administered
  • Feverish for a few days, body ache and headache
  • Rashes, nausea, and vomiting.

On the other hand, these symptoms slowly fade away in a few days. Very serious symptoms and side effects are rare. These include,

  • Thromboembolic symptoms in general
  • A few concerns with people of blood thinners were initially present. This has however been cleared and the Indian Council of Medical research. It has stated that people on long-term blood thinners can also take this vaccine.
  • Individuals on stable anticoagulation therapy with a normal scheduled INR (International Normalized Ratio), simple blood thinners with a stable medical disease condition can receive that vaccine. However, the bleeding might take a bit longer to arrest. The concerning physician can be consulted before the vaccine.

TRIALS:

Both the vaccines are in the phase 3 trial.

A lot of fears and uncertainties going around this concept of vaccines are due to the incomplete trials. These vaccines have no market use authorization yet from DCGI. The vaccines were available to the public before the completion of the trials due to the situation.

Both the vaccines have 2 doses (the initial dose and the booster dose). Vaccines are 28 days apart.

CONTRAINDICATIONS FOR THE VACCINES:

Let’s take a look at the contraindications of both the vaccines.

COVISHIELD AND COVAXIN:

  • Severe allergic reaction to the ingredients of the vaccine
  • Any form of allergy during the 1st dose of the vaccine
  • Fever or any acute infection during the time of the vaccine.
  • Pregnant or breastfeeding individuals

On the other hand, if you are developing side effects or any abnormality it is very important to contact your nearest health care provider.

INTERNATIONAL:

Likewise, at an international level, some of the vaccines available are the

  • Moderna from Pfizer (most common)- 95% efficacy
  • Astrazeneca
  • Oxford vaccines
  • Johnson and johnson

THINGS TO MENTION TO YOUR HEALTHCARE PROVIDER WITHOUT FAIL:

  • If you are on any medication for a chronic illness. In addition, duration of the medication.
  • If you are on any blood thinners
  • Having fever
  • Are allergic to the contents of the vaccine or had an allergic episode to the 1st dose of the vaccine
  • Pregnant or breastfeeding
  • Having received another Covid vaccine
  • Immunocompromised or taking such drugs (Eg. post-transplantation, transplant recipients, HIV positive individuals)

Apart from these a commonly asked question is about the duration of protection against Covid 19. The straight fact is, it is unknown as of now.

Consequently, immunity develops in the body 4 weeks after the 2nd dose.

IMPORTANT THINGS TO NOTE:

  • After getting yourself vaccinated, never forget to get a vaccine card.
  • Always go in for the same type of vaccine. For example, if your first dose was from covaxin stick to the same. Never switch vaccines.
  • Register for the vaccine and take it during your turn without fail
  • To sum up, always remember, vaccines are not magic potions. Moreover, continue safety precautions and practice distancing properly.


Like it? Share with your friends!

Dr Kavitha M

I am an undergraduate degree holder in dentistry. I have a great interest in music and reading. I am a linguaphile. My areas of interest lie in psychology, medical imaging, diagnostics, and oncology. I am a person who focuses more on the emerging areas of forensics.

0 Comments

Your email address will not be published. Required fields are marked *