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COVAXIN vs. COVISHIELD: COVID-19 Vaccines, Success Rate, Cost


India has authorized two vaccines against COVID-19, one co-developed by AstraZeneca and the University of Oxford, and the other by the Indian pharmaceutical company, Bharat Biotech.. Both vaccines have been approved for restricted use in emergency situations.

Both vaccines are “approved for restricted use in emergency situations.” says.

COVID-19 Vaccines: What are COVAXIN and COVISHIELD?

Covaxin, a COVID-19 vaccine, is India’s first vaccine for coronavirus. This is a highly purified and inactivated vaccine manufactured on the Vero cell production platform, which has a well-established track record of safety and efficacy in the country and worldwide.

Covishield on the other hand is the Indian name of The University of Oxford, AstraZeneca’s AZD-1222 (ChAdOx1) recombinant chimpanzee adenovirus vector vaccine. The drug has shown 72% efficacy in global clinical trials and was approved in the UK at the end of December 2020.

Developers and Manufacturers

Covaxin was developed locally by Hyderabad-based Bharat Biotechnology International Co., Ltd. in association with the Indian Council for Medical Research. Bharat Biotech has conducted studies in non-human primates too. In the current phase 3 of clinical studies, Bharat Biotech has 24,000 volunteers out of the planned 26,000, to whom it administers two equal doses of the vaccine 28 days apart.

Covishield has been developed by Oxford University and manufactured by AstraZeneca and in India has been manufactured in Serum Institute of India, Pune. In addition, the Serum Institute of India was authorized to conduct a phase II / III clinical trial involving 1600 participants in the country.

Both vaccines are safe, effective, easy to use, and suitable for Indian weather conditions and should be administered in two doses. All vaccines should be stored at 2-8°C.

Trial and Efficacy

The Serum Institute of India conducted over 23,745 overseas participants showing an overall result of 70.42 percent efficacy. In India, during phases two and three, 1,600 participants took part, and the results were comparable to that of the first phase of the trial.

Why the Emergency Use Authorization for Vaccines?

Manufacturers of vaccines, drugs, diagnostic tests, and medical devices must first obtain approval from regulatory agencies before the public can use them. These approvals depend on evaluating their safety and effectiveness based on test data. The regulatory agency must also approve each stage of the trial.

How Does Covaxin Work?

After the injection, immune cells can still recognize the dead virus, prompting the immune system to produce antibodies against the virus.

The Indian laboratory uses the inactivated virus in its immunizer, a technology commonly used in vaccine manufacturing. It works like this: from an isolated sample of the virus, scientists grow the virus, accumulating a large stock. Then, they immerse the virus in a chemical which “turns off” the microbe and leaves it harmless to human health. The virus loses its ability to replicate but remains with its proteins intact.

Inactivated viruses are mixed with an adjuvant, which is nothing more than a compound that strengthens the immune response, thus boosting the vaccines’ effectiveness. When the immunizing agent is applied to the patient, inactivated viruses are swallowed by cells such as macrophages that contain antigens – substances that trigger the production of antibodies. This is where the battle begins.

By swallowing the virus and digesting its proteins, cells with antigens take specific proteins from the virus. Some of them end up being exposed, on the cell surface, as a signal. Thus, T lymphocytes, viral fighting cells, recognize fragments of the virus and start their fight. When they connect to the invader with the help of their proteins, they also summon other immune system soldiers.

What Is The Controversy About Covaxin?

It all started when the regulator stated that the vaccine had been approved as an adequate preventive measure in emergencies in the public interest, and restricted use in clinical trials, especially in the case of mutant infections. Both manufacturers and drug regulators confirm that covalent enzymes are safe and provide a powerful immune response. However, experts wanted to know how millions of vulnerable people can use vaccines urgently while vaccine trials are still ongoing.

Bharat Biotech indicates that it has started phase 3 of its clinical trials, which consists of administering the vaccine candidate and a placebo to thousands of volunteers to verify its effectiveness and its benefit/risk ratio, in mid-November. This step is not yet complete. Also, the data from phases 1 and 2 have not been fully published. This has led several major players in the Indian scientific community to express their concerns.

The vaccine has attracted strong attention due to the lack of efficacy data and approval of an unfinished research vaccine.

COVAXIN vs COVISHIELD Success Rate, Cost

How Effective Is Covisheild?

International clinical trials of the Oxford AstraZeneca vaccine show that when people inject half a dose and then inject the full dose, the effective rate reaches 90%.

However, unpublished data indicate that a longer interval between the first and second injections can increase the overall effectiveness of the vaccine injection in such a subgroup. Effectiveness of 70% was found in patients after the first injection.

Are There Other Vaccine Candidates?

Other candidates at different stages of safety and efficacy trials conducted in India include:

  • ZyCov-Di, developed by ZydusCadila, headquartered in Ahmedabad
  • A vaccine was developed by Biological E, India’s first private vaccine production company based in Hyderabad, in collaboration with Dynavax and Baylor College of Medicine in the United States.
  • HGCO19 is the first mRNA vaccine in India. It is produced by Pune-based Genova and Seattle-based HDT Biotech Corporation (HDT Biotech Corporation). It uses a small amount of genetic code to cause an immune response.
  • Nasal vaccine from Bharat Biotech
  • Sputnik Type V vaccine candidate developed by Dr. Reddy’s laboratory and Russia’s Gamaliya National Center
  • The Serum Institute of India and the US vaccine development company Novavax are developing a second vaccine.

Mass Vaccination Campaign

The Serum Institute of India has already stored 50 million doses of the vaccine ready for distribution this month. It is ready to ship them to 30 to 40 government sites across the country.

India already has a large established network as part of its universal vaccination program, inoculating approximately 55 million people per year. The analysts said that this means that the country’s health system is relatively well prepared for immunizations against COVID -19.


In September, the Serum Institute of India vowed to manufacture and supply 200 million doses of COVAX – a World Health Organization vaccine coalition created to ensure impartial access to COVID -19 vaccines.

Frontline workers will get the vaccine free of cost. The price of Covaxin will be less than Rs 100while the cost of Covishield would be around Rs 400.

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