When India’s first indigenous DNA vaccine platform, Zydus Cadila’s ZyCoV-D vaccine, was approved for emergency use authorisation in August 2021, most expected it would be used to roll out the Covid-19 vaccination programme for the country’s children. ZyCoV-D is the first vaccine approved for use in India in those aged 12 years and above

But in January 2022, when the country began vaccinating 15-17-year-olds, ZyCoV-D was nowhere in the picture. Instead, the government relied on Covaxin, even though it had placed an order for one crore ZyCoV-D doses and applicators costing at least Rs 385 crore.

Zydus Cadila’s first batch of vaccines was manufactured between August and September 2021. The vaccine currently has a shelf life of six months from the date of manufacture. This means it is slated to start expiring from February-March.

While Zydus Cadila has applied for an extension, the Drug Controller General of India is yet to approve it. Managing director of Zydus Group, Sharvil Patel, said the company expects the drug regulator to soon extend the shelf life of ZyCoV-D. Even if some stock expires, it won’t be “a large quantity”. “A couple of lakhs may be,” he told Scroll.in.

But the question arises: why has the vaccine not been used by the Indian government in its vaccination programme so far?

An official from the Union Ministry of Health and Family Welfare, who did not want to be identified, said the company faced “some difficulty in bulk production and batch testing of doses” at their manufacturing unit, leading to a delay in scaling-up the stockpile.

A member from the National Technical Advisory Group for Immunisation said they have been waiting for the company to deliver doses. According to Patel, the company wanted to stockpile adequately before launching the vaccine. Zydus Cadila did not clarify on the current quantity of vaccine stock available with the company.

Shilpa Medicare, with which Zydus Cadila has tied up to make the drug substance, said it is “too early” to comment on manufacturing. The drug substance refers to the unformulated active substance which goes into making the vaccine. According to Patel, Shilpa Medicare will begin production in February. A health ministry official also said Zydus Cadila has indicated that it may start delivering the doses from February.

A needle-less shot

ZyCoV-D vaccine, manufactured by the Ahmedabad-headquartered Zydus Cadila, is a three-dose vaccine. Every recipient needs to be given three doses: on day zero, day 28 and day 56.

The doses are administered subcutaneously, or below the skin, using a needle-less applicator instead of a syringe. The applicator is placed in a gun which is then used to administer the vaccine dose. The gun, which costs Rs 30,000, has to be replaced after giving 20,000 shots.

In November 2021, the Centre placed an order for one crore doses – each dose costs Rs 265 and requires an applicator priced at Rs 93, excluding GST. Till the end of November 2021, the Centre had spent Rs 19,675.4 crore on procuring various Covid-19 vaccines.

Delayed timeline

At a press conference in August 2021, Zydus Cadila’s managing director Patel had said that by September, the company will be able to supply 30 lakh-40 lakh doses, which would be scaled up to one crore by October and three to four crore by December. The timeline could not be matched.

In October 2021, the first few batches of more than 1.50 lakh doses underwent the mandated random testing at a central drug laboratory in Kasauli and were approved. By the end of November, the laboratory had tested 2.37 lakh doses of ZyCoV-D in seven batches. Patel said it took longer than expected to increase production. “The scaling up is underway,” he said. “We want to launch when we have enough stocks.”

ZyCoV-D vaccine is a three-dose vaccine. Every recipient needs to be given three doses: on day zero, day 28 and day 56.Credit: Zydus Cadila

Zydus Cadila has tied up with Karnataka-based Indian pharmaceutical company Shilpa Medicare for manufacturing the drug substance. When contacted, Vinay Konaje, managing director of Shilpa Biologicals which comes under Shilpa Medicare, said it is too early to comment on the manufacturing process.

According to Patel, Shilpa Medicare is expected to begin production from February. “They will start by producing 10-20 lakh per month,” said Patel. Zydus Cadila also has a manufacturing licence and technology transfer agreement with Korean company Enzychem Life to produce an estimated eight crore doses in 2022.

“To scale up and augment our supplies, we have already initiated tech transfers for our vaccine with Shilpa Medicare for the drug substance and Enzychem Life Sciences of Korea for exports,” said a spokesperson from Zydus Group.

The spokesperson said the company also plans to enter the private market “shortly” and that private hospitals will be able to purchase vaccines directly. The pricing of the vaccine will be decided closer to the launch date.

Concerns over expiry of doses

If stockpiling of the vaccine began between August and September, as Patel had indicated, then four to five months have passed since the first batch of doses was manufactured. This suggests that some stocks could expire by February-March – unless the shelf life of the vaccine is extended soon.

On January 20, a spokesperson of Zydus Cadila claimed ZyCoV-D’s shelf life had been extended till nine months. But there was no confirmation from the Drugs Controller General of India.

Joint Drugs Controller Dr S Eswara Reddy said on January 19 that the regulator has not yet extended the shelf life of ZyCoV-D. “For now, it remains six months,” said Reddy.

In December, the government, too, said in Lok Sabha that the shelf life of the ZyCoV-D vaccine is six months.

KL Sharma, former joint secretary in the Ministry of Health and Family Welfare, said that to extend the shelf life, a company has to submit stability test reports – as Zydus Cadila says it has done – showing that the vaccine preserves its quality at the assigned room temperature for a prescribed period. “The subject expert committee usually deals with the approval of vaccines. The DCGI can approve the extension of shelf life,” said Sharma.

States prepared for roll out, but wait for doses

The delay in rolling out ZyCovd-D acquires more significance in the light of concerns over the adequacy of Covaxin stocks.

On January 13, Maharashtra health minister Rajesh Tope had flagged a shortage of Covaxin in the state for vaccinating teenagers and demanded 40 lakh doses from the Centre. In response, the Centre said the Maharashtra government had an unused stock of 24 lakh doses of Covaxin. According to senior Maharashtra officials, the roll out of ZyCoV-D should be permitted if it has received approval and some of its stock is ready.

On December 1, seven states – Maharashtra, Tamil Nadu, West Bengal, Uttar Pradesh, Bihar, Jharkhand and Punjab were shortlisted for the launch of ZyCoV-D. The shortlisted states were asked to select districts with poor vaccination coverage for the launch of the vaccine.

Punjab’s Covid-19 nodal officer Dr Rajesh Bhaskar said the Centre had last year promised 5.70 lakh doses of ZyCoV-D. “But it’s been a few weeks now and we are still waiting. We have finished training health care workers on using the needle-less applicator to administer vaccines,” he said. In Punjab, three districts have been shortlisted for the roll out.

In Uttar Pradesh, 14 districts have been shortlisted, state additional chief secretary Amit Mohan Prasad told Scroll.in.

Maharashtra’s Nashik and Jalgaon districts, both with lower vaccination coverage than other districts in the state, have been shortlisted. All health workers posted at vaccination centres underwent training in December, according to Maharashtra immunisation officer Dr Sachin Desai. “The Centre had supplied the applicator and gun for training,” said Desai. “We are yet to receive doses.” State additional chief secretary Dr Pradeep Vyas said there has been no communication from the Centre on rolling out the vaccine.

ZyCoV-D is also yet to get approval for use as a booster shot since data on its efficacy as a third dose is still pending. A member of the National Technical Advisory Group on Immunisation said since a large percentage of the adult population has already been vaccinated with Covaxin or Covishield, ZyCoVD’s one crore doses, as ordered by the government, may find use as booster shots or for immunisation of adolescents and teenagers.

Meanwhile, the Christian Medical College in Vellore, which is studying the efficacy of mixing and matching vaccines for booster shots, is expected to complete recruitment for Covaxin by this week. The institute’s virologist, Dr Gagandeep Kang, said the trial results are expected in a month’s time. “We had completed the trial study for the Covishield arm last September. But the trial is blinded. Until we finish the Covaxin arm, the results cannot be known,” she said.

The clinical trial is studying the efficacy of Covishield as a booster in people who were given Covaxin as their primary vaccine and vice versa. Kang said that since ZyCoV-D has not yet been granted approval for use as a booster dose, it was not included in the trial.

This reporting was supported by a grant from the Thakur Family Foundation. Thakur Family Foundation has not exercised any editorial control over the contents of this article.