Phase-3 Trials Show Covaxin 93.4 Per Cent Effective Against Severe COVID-19 But Supply Marred By Delay In Manufacturing

Two doses of Covaxin — the vaccine indigenously developed by Bharat Biotech — are 93.4 per cent effective against severe COVID-19 disease, as per the results of the Phase-3 trial. Against asymptomatic COVID-19 disease, it is 63 per cent protective.

It also offers 65 per cent protection against the Delta variant of the novel coronavirus, the variant most widespread in India and linked to a rising number of cases across the world, including Europe and United States.

Yesterday (3 July), Hyderabad-based Bharat Biotech India Ltd. publicised the long-awaited results of the Phase-3 trial of Covaxin. The trial involved nearly 25,800 volunteers spanning 25 hospitals across India.

The pre-print revealed that in those 60 years and older, the vaccine was 67.8 per cent effective and 79.4 per cent effective in younger people.

“Safety analysis demonstrates adverse events reported were similar to placebo (or those who got a dummy dose), with 12% of subjects experiencing commonly known side-effects and less than 0.5% of subjects feeling serious adverse events,” read the Bharat Biotech statement as reported by The Hindu.

Against symptomatic COVID-19, the Phase-3 trial results showed that Covaxin had an overall efficacy of 77.8 per cent, higher than that of the AstraZeneca vaccine (70.4 per cent) reported from the Phase-3 trial results published in Lancet in January this year.

AstraZeneca vaccine is marketed in the country as Covishield by Serum Institute of India (SII).

Along with partner scientists at the Indian Council of Medical Research, Bharat Biotech developed Covaxin against the COVID-19 infection. It began recruiting volunteers in November 2020 and completed the Phase-3 trials in January 2021. The latest Covaxin study is on a pre-print server and yet to be peer-reviewed.

The medical professionals across India welcomed the Phase-3 trial results.

The Hindu report quoted SP Kalantri, Director and Professor of Medicine, Mahatma Gandhi Institute of Medical Sciences, Wardha, as saying that the pre-print was rich in detail and, on preliminary reading, revealed a trial that was “well-conducted” and presented people with an informed choice on the vaccine’s efficacy.

“The true test of a vaccine is whether it protects from hospitalisation and death. The reported 93.5 per cent is very good, and protection in those over 60 as well as against the Delta variant, too, are encouraging,” Kalantri stated.

He also said that it would be unwise to speculate which one was superior — Covishield or Covaxin — as there were variations in the conduct of the trials.

“The overall efficacy is wonderful news. ICMR-NIV and BBIL have had very fruitful interactions during this exhilarating journey. Sera [from blood samples] have also been evaluated against viral variants detected in India i.e., the Alpha, Beta, Zeta, Kappa and Delta. The making of this vaccine entirely on Indian soil is a matter of great pride to every Indian,” Priya Abraham, Director, ICMR-National Institute of Virology, was quoted as saying.

NIV is among the partner labs involved manufacturing Covaxin, producing the strain of the virus used in the process.

Production Targets

While the Phase-3 trial results give a good news, the sobering fact remains that Bharat Biotech is struggling to meet its supply targets.

The company is expected to deliver 400 million (40 crore) doses between August and December, based on government’s projected availability of vaccines. According to Centre’s affidavit in the Supreme Court on 26 June, till 12 June, Bharat Biotech supplied 2.8 crore doses to the Centre, a fraction of the total purchase order of 8 crore doses.

Reportedly, from the government's 12 March purchase order of 2 crore doses, 18.4 lakh vaccine doses are still pending; and supplies are yet to commence against a 5 May order for 5 crore doses, to be delivered between May and July.

A senior company executive was quoted as saying that Bharat Biotech will continue to produce 2.5 crore doses per month of Covaxin till at least August this year, “but hopes to be producing 6-7 crore doses per month by the end of the year”.

“We actually see annualised production, and it is going to reach 80 crore mark by the end of this year,” he said.

In April, the number of doses manufactured per month stood at 1 crore. The government had then said that it was targeting to produce 6-7 crore vaccine doses per month in July-August, and reach nearly 10 crore by September 2021. This seems to be a long shot now.

The main culprit of the delay is complicated manufacturing process of vaccines. In a statement in May, Bharat Biotech said, “Production scale up of vaccines is a step-by-step process, involving several regulatory standard operating procedures of good manufacturing practices. There is a four month lag time for Covaxin to translate into actual vaccination.”

A manufacturing facility needs to fulfil formalities regarding technology transfer, confidentiality clause, signing an MoU with Bharat Biotech, apart from taking permission from the government, and building a BSL Category-III production unit to manufacture the vaccine.

The union government, under Mission Covid Suraksha, is augmenting the vaccine supply by ramping up production facilities. State government are also contributing funds to the facilities in their states.

In the next two months, Bharat Biotech will be starting production in two of its facilities in Ankleshwar, Gujarat, and Bengaluru, Karnataka. These facilities are being repurposed and the production is likely to start in next two months.

Haffkine Bio-Pharma, a Maharashtra government undertaking, is expected to start Covaxin production in 8 months. The facility will have the capacity to produce around 2 crore doses per month.

To cover its entire population by year end, India will need 216 crore vaccine doses in a span of five months, or a production capacity of roughly 40 crore doses a month.

The current capacity of Covishield is 6.5 crore a month, while that of Covaxin is 2.5 crore. The production for the Sputnik V has only recently begun at Panacea’s plant in the northern state of Himachal Pradesh, and Moderna's vaccine, that became the fourth one to get emergency use authorization from the Drugs Controller General of India (DCGI), is yet to start production in India.

The manufacturers of all three — Covishield, Covaxin, and Sputnik V — have set the target of eventually producing 10 crore doses a month.