India may soon have Covid-19 vaccines for children. All you need to know

Zydus Cadila DNA-plasmid vaccine is the prime contender. It has held trials on children aged 12 years and above

India may soon have at least a couple of options for adolescent Covid-19 vaccines, if things go well.

One of the prime contenders is the Zydus Cadila DNA-plasmid vaccine which has held trials on children aged 12 years and above, and one could be a foreign vaccine – either Pfizer-BioNTech or Moderna’s mRNA vaccine – if the legal issues are sorted out soon. Indigenous vaccine maker Bharat Biotech’s inactivated whole virus vaccine is now undergoing trials on children aged two years or more. However, there is time till it is approved and available in the market. One can expect the vaccine by the end of 2021.

Why is a children's vaccine necessary?

Since the beginning of the Covid19 pandemic, parents have taken comfort from the fact that children, if infected, do not usually present serious symptoms and recover soon.

However, all are not so lucky, and some unfortunate children do go on to develop multisystem inflammatory syndrome in children (MIS-C), a serious condition that appears to be linked to coronavirus disease 2019 (Covid-19).

“Most children who become infected with the Covid-19 virus have only a mild illness. But in children who go on to develop MIS-C, some organs and tissues — such as the heart, lungs, blood vessels, kidneys, digestive system, brain, skin or eyes — become severely inflamed. Signs and symptoms depend on which areas of the body are affected,” says the Mayo Clinic.

The urgency for a children's vaccine is thus growing fueled by multiple factors – protecting the children, reducing transmission and also as a critical pre-condition for re-opening schools.

A senior government official said that India is keen to have a vaccine option for children very soon for the above reasons. “However, one has to assess and analyse the safety and tolerability in children before any vaccine can be approved,” he noted.

A few Covid19 vaccine options for children or adolescents is available now globally – Pfizer-BioNTech’s and Moderna’s mRNA vaccines, Zydus Cadila’s DNA plasmid and Bharat Biotech’s inactivated whole virus vaccine, China’s Sinovac and Sinopharm vaccines.

Of these, the Pfizer and Moderna shots have been used in limited doses for adolescents, and may be soon available for India as well. The US regulator has now asked both companies to start trials on the 5-11 years age group.

VK Paul, member (health), NITI Aayog had said earlier this month,” "We are in touch with them (Moderna and Pfizer). We are holding discussions. It is a process of negotiation and dialogues. We are trying to get a solution on contractual and commitments issues. This process is ongoing.”

In what stages of development are the children vaccines now?

Bharat Biotech has already conducted trials on children 12 years and above and is now doing trials on smaller children who are two years or older. Trials have started at the All India Institute of Medical Sciences (AIIMS), New Delhi, and some other centres. The company did not give timelines on when the trials could be over. However, a senior executive told Business Standard that this was a ‘safe bet’ as the vaccine was already approved for adults and the platform was ‘tried and tested’.

“The children’s trial for Covaxin is to check safety and immunogenicity, and this is a quicker process than our phase 3 efficacy study, which we started in November last year. We will have the phase 3 efficacy analysis by July. The study in children would not take that long, and a couple of sites have already begun enrolling kids,” the executive said.

He added, “I don’t want to give a timeline. We can expect a pediatric Covaxin soon. It is a safe bet as it is already approved for adults and the technology platform is tried and tested.”

Source: media reports, company statements

Bharat Biotech is also betting on its intra-nasal candidate BB-154 as a pediatric candidate. The company has noted on its website that it is needle free, non-invasive, easy to administer (even without trained healthcare workers), and ideally suits children. The trials are on for this candidate too.

Bharat Biotech Chairman and Managing Director Krishna Ella had said last year: “Our vaccine is safe, and built on time-tested and proven technology. It can be given to a six-month-old or a 60-year-old.”

T Jacob John, senior virologist and former head of the departments of clinical virology and microbiology at Christian Medical College, Vellore said, “Covaxin is an inactivated virus based vaccine. It is the same technology as the injectable polio vaccine and the hepatitis A vaccine. These vaccines are given to infants and have proven to trigger immunogenic response in children. Covaxin should also work on children above 2 years of age. However, this needs to be backed up by data and hence trials are necessary.''

John added that if the world wanted to get rid of the coronavirus, vaccinating children was an important step as they are a link in the transmission process.

As for Zydus, the Ahmedabad-based pharma major is awaiting approval from the Drugs Controller General of India (DCGI) for its vaccine ZyCoV-D. It has sought approval for use in children above 12 years, and has already submitted safety and tolerability data from the phase 2 clinical trials and has generated data on 1000 adolescents (between 12 to 18 years) from its phase 3 trials too. The 1000-volunteer data will be submitted with the regulator soon.

Meanwhile, the company also plans to start clinical trials on children 5 years and above soon for its DNA-plasmid technology based Covid19 vaccine.

Zydus Cadila MD Sharvil Patel had told Business Standard a week back: “now plan to start trials on children aged five years and above if the regulator approves.”

Paediatric vaccine is also a sizeable market

Paediatric vaccines are also a sizable market. A Mumbai based analyst noted, “It is estimated that 350-400 mn people in India are below 18-years of age. Considering two doses Covid vaccine regimen, this would translate into 700-800 mn doses potential demand easily.”

According to a UNESCO estimate, around 321 million Indian children were asked to stay home when the lockdown began at the end of March last year.