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Covaxin or Covishield : Which vaccine to go for?

  • Adrija Ray Chaudhury | Team PresentMirror | Updated: Jan. 12, 2021, 8:44 a.m.

India's drugs regulator DCGI has approved Oxford-Serum Institute's Covishield and Bharat Biotech's Covaxin for restricted emergency-use. While experts are alarmed at the grant of regulatory approval of Covaxin in spite of the lack of efficacy data, Covishield attracts a distinct concern altogether. These concerns however are with every vaccine out there in the world. It doesn’t demote the importance of fight against COVID-19 that India has begun with two desi vaccines.


Covishield, the vaccine candidate from Pune-based Serum Institute of India, was approved by a Subject Expert Committee (SEC) of the Drug Controller General of India (DCGI) on 1st January, 2021. A couple of days later, on 3rd January the authorities also approved Covaxin, an inactivated virus based COVID-19 vaccine being developed by Bharat Biotech in collaboration with the Indian Council of Medical Research for restricted use in emergency conditions.

Covishield used a ChAd0x1 virus, which is a weakened version of the adenovirus that causes common cold in Chimpanzees. A coronavirus spike protein has been injected into the ChAd0x1 virus which will be detected by the human body on inoculation and immunity will be developed accordingly. On the other hand, Covaxin is India’s first indigenous vaccine against Covid-19.Covaxin is an inactivated vaccine. This destroys the pathogen’s ability to replicate, but keeps it intact so that the immune system can still recognise it and produce an immune response.

Covishield vs Covaxin


Though currently the government is controlling the vaccination drive against Covid-19, and it is free. Different reports have cited different prices for both the vaccines. The Covishield vaccine is reported to cost the government around Rs 400-450 or Rs 200-225 per dose.

The pricing of indigenously developed Covaxin is not clear yet. However, some reports say Bharat Biotech has priced its Covid-19 vaccine at less than Rs 150.

Storage logistics

Both Covishield and Covaxin vaccines are easy to store as they require to be kept at 2-8 degree Celsius. Most vaccines commonly used in India are kept at this temperature range. This makes transport and local storage of both Covid-19 vaccines safe and easy for all parts of the country and an economical choice for the mass.


The two shots of the Covishield vaccine need to be spaced by six weeks. In the case of Covaxin, the interval between the two shots has not been yet prescribed by the Drug Controller General of India (DCGI) but it's developer Bharat Biotech had earlier said the second shot would be given after 14 days.


DCGI has said both Covishield and Covaxin are safe Covid-19 vaccines. DCGI VG Somani added, “[Both] vaccines are 110 percent safe. However, some side effects like mild fever, pain and allergy are common for every vaccine.”

Why are experts concerned about Covaxin?

The approval to Covaxin, whose phase 3 trial on about 26,000 volunteers is still underway, led to a massive outcry in the scientific community as its efficacy is yet to be established. In a statement, All India Drug Action Network said that with respect to Covaxin, they are concerned because it signifies the grant of regulatory approval without any reliable data.

“The Phase 3 trials are currently ongoing and it is too early for data to meet the criterion for an interim analysis. The only human data available on safety and immunogenicity is on 755 participants in Phase 1 & 2 trials. Other than this, there is data from animal studies. This would amount to rolling out an untested and unproven vaccine to the public which raises concerns,” the statement said.


Image Credits: Hepatitis B Foundation

How are phase 3 trials conducted?

A drug or a vaccine is initially gauged through preclinical research which uses animals to find out if a drug, procedure, or treatment is likely to be useful. A clinical trial is only done when there is good reason to believe that a new test or treatment may improve the care of patients. Before clinical trials, tests and treatments are assessed in preclinical research. Although the accelerated pace in authorizing vaccines have left very little room for such detailed analysis, one cannot expect medical visionaries to be frugal in their assessments.

Phase 3 trials come after 3 sessions of trials viz. Phase 0, Phase 1 and Phase 2. Phase III trials compare a new drug to the standard-of-care drug. These trials assess the side effects of each drug and which drug works better. Phase III trials enroll 100 or more patients. Often, these trials are randomized. This means that patients are put into a treatment group, called trial arms, by chance. Randomization is needed to make sure that the people in all trial arms are alike. This lets scientists know that the results of the clinical trial are due to the treatment and not differences between the groups.

Every patient in a phase III study is watched closely. The study will be stopped early if the side effects of the new drug are too severe or if one group has much better results. Detailed reports on Phase III clinical trials are often needed before the authorities approve the use of a new drug for the general public. And not to be surprised, this is even followed by a Phase 4 trial before the vaccine is put out into the market. Nevertheless, Bharat Biotech CMD Krishna Ella has asserted that the clinical trials have been conducted globally over a period of time and it is one of the safest vaccine makers. He also hailed the decision of DCGI to approve Covaxin for emergency restricted use and termed it as a giant leap for innovation and novel product development in India.

Covishield-a better choice from a safety point of view?

Although Covishield has completed phase 3 trials globally and also across the country, researchers are apprehensive that the data for all participants in the Indian trial were not submitted. Shahid Jameel, Indian virologist and Director of Trivedi School of Biosciences at Ashoka University, spoke about the need for transparency which is unfortunately absent in case of Covishield. He said, “For Covishield, there are no final results. And the concern is the same with Covaxin, where the trials are still ongoing. The safety of vaccines on individuals is tested in Phase 2 of trials and then safety is checked on larger populations in Phase 3. In both these vaccines, it needs to be checked on a larger population still.” But what is still unsettling is that WHO has yet not cleared AstraZeneca for emergency use.

Amidst the growing concern, an agreeable news is likely to bring a news of encouragement to scientists across the country. Private Brazilian clinics have planned to buy 5 million doses of a COVID-19 vaccine developed by India’s Bharat Biotech. This should be the first vaccine available on the private market in Brazil according to reports.The plan is for the 5 million doses of Covaxin to arrive in Brazil in mid-March, to be sold by private clinics.

Anvisa said in a statement on Sunday that Covaxin does not fit the continuous data submission process for vaccine registration and the vaccine would have to undergo clinical trials in Brazil.


Image Credits: Livemint

As many as 41 destinations across India have been finalised for the delivery of Covid-19 vaccines.The national capital and Karnal will be made mini hubs for delivery of coronavirus vaccines in northern India. For the eastern region, Kolkata will be the hub and will also be a nodal point for the northeast. Meanwhile, Chennai and Hyderabad will be the designated points for Southern India.

India already runs the world's biggest immunisation programme, inoculating more than 40 million newborns and pregnant women against 12 diseases every year. It also has a well-oiled electronic system to stock and track these vaccines. We are hopeful that such spacious provisions might be able to effectively handle Covid-19 crisis in India.

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