THIS WEEK ONE of the two vaccine manufacturers running trials to assess the safety and efficacy of a Covid-19 vaccine for children under 12 has said it expects to apply for emergency use authorisation in the US by next month.

In Ireland, Covid vaccines are not approved for use in children aged under 12 and the European regulator has not yet begun assessing data from ongoing clinical trials for this age group.

However a small number of countries are now taking steps towards immunising younger children and the US may be next. 

Vaccine trials

PFizer/BioNTech and Moderna are currently running trials to assess the safety and efficacy of their mRNA vaccines in this younger age cohort.

In February 2021, Pfizer/BioNTech began testing the vaccine on healthy children to assess the safety and immune response against Covid-19.

A reduced dosage has been given to children who participated, but it is still a two-jab vaccine.

Children aged five to 11 received a 10 microlitre (0.01 millilitre) dose of the vaccine – adults receive 30 microlitres per jab.

Some 4,500 children aged six months to 11 years were enrolled in the US, Finland, Poland and Spain at more than 90 clinical trial sites.

Pfizer has said it believes successfully vaccinating children will contribute to global protection against the disease as children under 15 account for 26% of the world’s population.

Moderna’s KidCOVE study which began in March this year involves children aged six months to less than 12 years. 

Participation lasts 14 month with phone calls, telemedicine visits and up to seven visits to study sites for children who are involved.

Children in this trial are given two injections about 28 days apart, with some receiving a placebo.

The adult dosage for each Moderna jab is 500 microlitres (0.5 millilitres). Children in the trial aged two years to less than 12 years received either 50 microlitre doses or 100 microlitre doses. 

Approval in the US

At an event last week Pfizer CEO Albert Bourla said the company expects to release clinical trial data on use of the vaccine in children aged six months to five years at the end of October, but data for children aged five to 11 will come sooner.

He said the pharmaceutical company may be ready by the end of September to submit its data on the 5-11 group to the Food and Drugs Administration, which will then make a decision on granting Emergency Use Authorisation (EUA).

Emergency use is granted by the FDA on the back of two months of safety monitoring data on study participants.

Moderna this week told investors that it expects data on the 5-11 age group by the end of this year. 

When could we expect an approved vaccine for this age group in Ireland?

While some countries have been making moves towards vaccinating younger children, Ireland is awaiting approval by the European regulator – and even then it would have to be considered by the National Immunisation Advisory Committee. 

In Israel, the administration of coronavirus vaccines to children aged 5-11 has already been authorised, but only for children with serious underlying conditions that would make them vulnerable to serious Covid-19 illness. 

Just this week China’s disease control authority also said the country should consider inoculating children aged under 12 to boost its vaccine drive. 

However in most countries there has been more caution around the rollout of Covid vaccines to younger children as health authorities wait for solid clinical trial data and approval by regulatory agencies. 

Chief White House medical adviser Dr Anthony Fauci has said there is a “reasonable chance” that Covid-19 shots will be available to children under 12 by mid-to-late autumn or early winter. 

While FDA approval would signal confidence in a vaccine for use in children, it would still require approval from the European Medicines Agency (EMA) before Irish health officials would consider its use here.

The HSE’s vaccine registration portal opened for parents and guardians to register their children aged 12-15 for a Covid vaccine in early August. Within two days almost 65,000 children in that age group had been registered for a vaccine and one week later that figure had increased to 120,000 registrations.

Speaking this week to the Oireachtas Health Committee, Professor Karina Butler, Chair of the National Immunisation Advisory Committee (NIAC), acknowledged ongoing studies, which are looking at the necessary dosage in children under 12 and whether a vaccine is even required for this age group.

She said schools had taken on board the need to keep the environment safe for children and it was fortunate that the majority of children who do acquire infection have mild symptoms. Professor Butler said this may also contribute to their overall immunity.

However she cautioned against complacency with public health measures for children.

“Our onus is to protect our children from this infection,” she said. “While most of them have a mild illness and don’t suffer consequences, there is the potential for significant illness and there is the potential for the post-Covid inflammatory syndrome that some children can have.”

Of the 30 children who were admitted to ICUs due to Covid-19 since the beginning of the pandemic, more than 20 were admitted due to the inflammatory syndrome.

“Covid is not something you want to expose your children to,” Professor Butler said.