Introduction:
COVID-19 (coronavirus disease 2019) is a contagious disease caused by a coronavirus called the SARS-CoV-2 (severe acute respiratory coronavirus 2). It was first identified in Wuhan, China in December 2019. The COVID-19 disease is predominantly a respiratory illness involving the lungs. They are also known to affect other organs of the body. The symptoms of COVID-19 range from mild to severe distress.
The World Health Organization declared a pandemic of coronavirus disease on 11th March 2020 which is the ongoing pandemic in the world. Since the beginning of the COVID-19 pandemic, there has been major speculation between the pharmaceutical industries in the development of vaccines against SARS-CoV-2. The COVID-19 vaccine is intended to provide acquired immunity against SARS-CoV-2 and is accepted for its role in reducing the severity and death caused by COVID-19.
What Is ZyCoV-D?
ZyCov-D is a vaccine formulated to use against COVID-19. It was developed by Candila healthcare limited, an Indian multinational pharmaceutical company located in Ahmedabad, with the support of the Biotechnology Industry Research Assistance Council. ZyCov-D is indicated for active immunization of people from 12 and above years of age. It is approved for controlled usage in emergency situations of COVID-19 in India.
What Are the Ingredients of ZyCoV-D?
The active raw material of the ZyCov-D vaccine is the DNA (Deoxyribonucleic acid) plasmid constructed with a spike protein gene region from the SARS-CoV-2 virus. It is conferred as an antigen inside the human body. The plasmid is produced from E.Coli cells. The inactive raw material is the phosphate-buffered saline used as a buffering agent.
What Is the Dosage Strength and Method of Administration of ZyCov-D?
ZyCov-D vaccination schedule consists of three separate doses given at an interval of 28 days each (day 0, day 28, day 56). The recommended quantity of each ZyCov-D dosage is two shots of 0.1 ml of the vaccine. Each 0.1 ml of ZyCov-D vaccine contains 1.0 mg of DNA plasmid.
The mode of administration of ZyCov-D is by a spring-powered jet injector (needle-free - pharmajet tropis device) through an intradermal (superficial between the layers of skin) route. Two shots are given at two separate sites.
How Was ZyCoV-D Developed From Clinical Trials?
Various clinical trials were conducted before the authorization of the ZyCov-D vaccine.
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Pre-clinical Trial:
Immediately after the outbreak of COVID-19, Candila healthcare decided to develop a DNA vaccine against SARS-CoV-2. Initially, the vaccine was subjected to preclinical trials in animals and it was able to pass out on animal models. The report of the study was published in the journal vaccine. After that, human trials were approved by the regulators.
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Phase I and II Trials:
The human trial of phase I of the ZyCov-D vaccine started on the 15th of July 2020 and continued until October 2020. The vaccine was tested on 48 healthy volunteered individuals in the age group of 18 to 55 years. The duration between the three doses was kept at an interval of 28 days. The vaccine was found to be safe, well-tolerated, and immunogenic at the end of the phase I trial.
Phase II trials of ZyCov-D were started by Candila healthcare on 6th August 2020 and continued till November 2020. 1000 volunteers participated in the phase II trial in a multi-centric, dose-escalation, randomized, double-blind placebo-controlled method.
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Phase III Trials:
After the positive result of phase II trials, the company announced a huge phase III trial with about 30,000 patients. The permission was granted by the Drug Controller General of India in January 2021. Phase III trials started with 28,216 Indian participants in the age group of 12 to 99 years. Of these, 1000 individuals were in the 12 - 18 age group. Candila healthcare submitted the interim results of phase III trials and reported the efficacy of the ZyCoV-D vaccine as 66.6 % against symptomatic COVID 19 cases and 100 % against moderate or severe covid-19 disease.
After all these trials, the Drug Controller General of India with expert advice from the Central Drugs Standard Control Organization approved the ZyCoV-D vaccine for restricted use in emergency situations in India.
Who Should and Should Not Get ZyCoV-D?
The decision of administering the ZyCoV-D vaccine must be taken by the healthcare provider depending on the person's situation and health condition. ZyCoV-D vaccine has been approved for restricted use in emergency situations in individuals 12 years of age and older.
The persons who should not take the vaccine are those who have severe allergic reactions to a previous dose of the ZyCoV-D vaccine or any other vaccine.
It is advisable to discuss the below-mentioned medical conditions with the physician before getting the ZyCoV-D vaccine.
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If there was an allergic reaction prior to any drugs, food, or vaccines.
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Currently, if there is a fever, cold, or any other infection.
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Suffering from bleeding disorder and on blood thinners.
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Immunologically suppressed and on drugs that affect the immune system.
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Pregnancy or planning to get pregnant.
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Already received another COVID-19 vaccine.
What Are the Risks Associated With ZyCoV-D?
Common side effects that have been reported with ZyCoV-D vaccine include:
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Redness and itching at the injection site.
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Mild pain and swelling at the injection site.
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Fever.
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Malaise.
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Nausea or vomiting.
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Diarrhea.
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Headache or dizziness.
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Muscle pain
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Fatigue or tiredness.
The above-mentioned symptoms are some of the possible side effects of the ZyCoV-D vaccine. Other than this, serious and unexpected side effects may occur. The ZyCoV-D vaccine is still being studied in clinical trials.
If there is any severe allergic reaction or serious side effects, it is imperative to reach a nearby hospital immediately.
Conclusion:
There are many unanswerable questions regarding the ZyCoV-D interaction with other vaccines, medication, and its effects on pregnant or breastfeeding women. Based on the clinical trials conducted over a shorter period of time, the ZyCoV-D vaccine was approved for emergency use in India. Therefore it is advisable to seek advice from the healthcare provider before making the choice of having the ZyCoV-D vaccine.
