Coronavirus: Why caution is more important than speed in rolling out COVID-19 vaccines for kids

  • Opinion
  • 02/12/2021

By Tony Walls for Newsroom

Many are calling for young children in New Zealand to be vaccinated against COVID-19 as soon as possible. 

The US Food and Drug Administration recently approved the Pfizer COVID-19 vaccine for emergency use in children aged five to 11 years. Even before completion of the clinical trial that led to this approval, some were asking for it to be rolled out here.

It would be prudent, however, to wait for more information on safety and efficacy before it is given to New Zealand children. Vaccine safety should be the top priority, and we need to carefully evaluate this vaccine, just like we would with any other new medicine.

Currently, we simply do not have enough information on potential side effects in young children.

To date, there has been a single-phase III clinical trial which vaccinated only 2200 children. Compare this to the millions of children worldwide who had received the rotavirus vaccine before it was introduced successfully in New Zealand.

Caution is warranted. We know that extremely rare but serious vaccine-related complications, such as myocarditis, have occurred in older children and adults receiving the Pfizer vaccine. These complications only came to light once the vaccines were given to millions of people.

With any new vaccine programme the risks of vaccination must be balanced against the risk of the disease. In the elderly who are at very high risk of severe COVID-19, the benefits of rolling the vaccine out early outweighed any risk of rare unknown side effects.

Children seldom get severe COVID-19 disease, so we need a higher level of certainty around the safety of the vaccine before deciding to use it or not.

Right from the start of the pandemic, reports from Wuhan in China suggested children were less likely to become unwell with COVID-19 than adults. This has not changed with the Delta variant.

Most people know that severe complications from COVID-19 in children occur rarely, but they may not realise just how rarely.

In New South Wales (NSW), during the current Delta outbreak, about 11,000 children have had a COVID-19 infection. Only about 1 percent of these children were admitted to hospital and there have been no COVID-related deaths.

Around 40 percent of the hospital admissions were for children who had non-COVID-19 related conditions. Those aged five to 11 years were the least likely of any age group to be admitted to hospital.

We know COVID-19 in healthy children is generally a mild illness so the question becomes - what is the purpose of vaccinating young children? A rollout of vaccination to children five to 11 years of age will be expensive and could take away resources from our already stretched childhood immunisation programme.

One of the main arguments for widespread vaccination of children is that if large numbers of children develop infection, even if it is mostly mild, some will develop severe complications and sadly even die. This is true for many common respiratory viruses, such as influenza or RSV, that spread widely in our communities every winter.

The reality is the risk of death from COVID-19 in children is incredibly small. In the UK, where the virus is widespread, 99.995 percent of all children who tested positive for COVID-19 survived. 

There will of course be a small number of children for whom the risk of COVID-19 infection is much higher. Among the small number of deaths in the UK, 60 percent occurred in children with pre-existing, life-limiting medical conditions. Others may have family members who are immunocompromised and cannot be vaccinated.

Influenza vaccine is funded in New Zealand for high-risk children and there is a strong case for doing a similar thing for COVID-19 vaccines.

Another suggestion is that vaccinating children of this age will prevent spread in the community. We don't know if this is true, because young children have not previously been vaccinated and modelling suggests any reduction in transmission gained by vaccinating this group is likely to be limited.

Research from schools in NSW show children infrequently pass on COVID-19 in the classroom and the greatest risk to children is from adults working in the school.

Most children who get COVID-19 catch it at home, so vaccinating as many adults as possible is still the best strategy for limiting community transmission.

Outside of the debate around the need for vaccination in young children, we need to consider what impact any potential vaccine programme would have on them.

We already know the worst impact of COVID-19 on children globally is through restrictions placed on them by public health measures. The most vulnerable populations have suffered the most from interventions including school closures.

The Ministry of Education has already stated no children will be excluded from education if they are not vaccinated. This is critical. However, in the era of unprecedented vaccine mandates it is not hard to imagine some children being excluded from other activities, including sports or social events, based on vaccination status.

Given COVID-19 is usually a mild disease in children, our best option currently is to prioritise safety and wait for more information on the vaccine before considering a national immunisation programme.

Fortunately, we will not have to wait long. The rollout is underway in the US and we shall soon know with more certainty if it is safe enough to give to our children.

Associate Professor Tony Walls is a Paediatric Infectious Diseases Specialist at the University of Otago, Christchurch, who has more than a decade of experience in vaccine research and policy work in New Zealand.

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