‘A complex decision’: COVID-19 vaccination and younger children

On Tuesday evening in the US, advisors for the Centers for Disease Control and Prevention (CDC) endorsed the emergency use of Pfizer among younger children.
 
Members of its Advisory Committee on Immunization Practices voted 14–0 to allow for the use of the vaccine in the 5–11 age group, opening up Pfizer vaccines to an estimated 28 million children around the country.
 
While the decision will not have an immediate effect on general practices involved in the COVID-19 vaccination rollout in Australia, its impact will be scrutinised carefully.
 
Therapeutic Goods Administration (TGA) national manager Professor John Skerritt last week confirmed Pfizer has already submitted most of the data for an application to approve its vaccine among the age group in Australia.
 
In mid-September, the vaccination program in Australia was also opened to adolescents aged 12–15.
 
But even though US regulators have given their approval, Associate Professor Margie Danchin of the Murdoch Children’s Research Institute (MCRI) believes more details will be needed in Australia in addition to clinical trials.
 
‘That [Pfizer] trial … provided really good information on the immunogenicity or the immune response, which was good in those children and equivalent to the older teenage group that they used as the comparator,’ Associate Professor Danchin told newsGP.
 
‘It did say that the vaccine is 90% effective against symptomatic disease, but the trial is not big enough to be able to tell us how effective it is against severe disease and hospitalisation.’
 
A decision by advisors to the US Food and Drugs Administration (FDA) to recommend the vaccine’s endorsement included details of clinical trials conducted by Pfizer. In an initial group of 2268 participants, 1518 received two paediatric doses (one third of the amount administered to adults), while the rest received a placebo.
 
They were followed up until at least two months after the second dose.
 
Results indicated the vaccine’s efficacy against symptomatic COVID-19 beyond seven days after the second dose stood at 90.7%, and there were no cases of severe COVID-19 among those who took part.
 
Associate Professor Danchin, who is the Group Leader for Vaccine Acceptance, Uptake and Policy at MCRI, says the length of time after the second dose in the trial was shorter than ideal. She believes the Pfizer-based program that is now primed to unfold in the US will provide a clearer picture of the risks, particularly of myocarditis and pericarditis, among younger children.
 
‘There’s only two months of follow-up after that trial, so normally we would want a bit more … to see if there are any other safety issues that may arise,’ she said. ‘The TGA is probably going to want more safety data in terms of some of those rare and more serious side effects.’
 
A final decision is not likely until at least early 2022, she believes.
 
‘Expanded set of issues’ in Australia
The circumstances surrounding the decision in the US are also very different in Australia.
 
The number of COVID-related deaths in the US is currently recorded as close to three-quarters of a million, including 657 children and teenagers aged under 18 (up until 23 October).
 
By contrast, Australia has reported a single death in the same age group – that of a 15-year-old girl in Victoria last month.
 
In the announcement of its recommendation for 5–11-year-olds, the CDC said the Delta variant has caused a surge of COVID-19 cases across the US.
 
‘During a six-week period in late June to mid-August, COVID-19 hospitalizations among children and adolescents increased fivefold,’ the press release reads.
 
The release also says vaccination and other preventive measures would help protect children, and that the vaccines’ side effects were ‘mild’ with the most common being a sore arm.
 
In addition to the different status of the pandemic in Australia, the Australian Technical Advisory Group on Immunisation (ATAGI) will have a much finer balancing act determining the risks and benefits.
 
Dr James Best, Chair of RACGP Specific Interests Child and Young Person’s Health, says that while the dangers are clearly much less pronounced among children, the circumstances in the US show they do exist.
 
‘We all know that the younger you go, the less risk of complications from catching COVID in terms of hospitalisation rates and serious complications,’ he told newsGP.  
 
‘However, it’s not zero, and there have been many cases recorded of children dying from complications of COVID overseas.’
 
For Associate Professor Danchin, work is still needed to understand the full impact of COVID-19 on younger children, even though it is usually less severe in this group.
 
‘There are some more severe components to the disease, like multi-system inflammatory syndrome in children, and also there are a lot of question marks around long COVID,’ she said.
 
‘The problem is really trying to understand the exact impact of COVID infection on children and then weigh that against the risks [of vaccination].’

GP Dr James Best expects the COVID vaccine rollout will be different for under-12s, if vaccination is approved for this younger cohort.
 
Associate Professor Danchin believes other factors are likely to come into play, including how far vaccination among younger children will affect the spread of the disease, as well as the wider impact on education. 
 
‘It is a complex decision, I think, [weighing up] the broader benefits of vaccination for children in terms of the potential impact on transmission, but also on getting them back to school,’ she said.
 
‘I think that will come into the decision-making as well.’
 
Challenges for general practice
Associate Professor Danchin believes any rollout in the 5–11 age group will predominantly be done through primary care, with school-based delivery also likely to be considered.
 
When asked about the specific challenges likely to be experienced by vaccinators in general practice, she believes discussions regarding the side effects could be more in-depth.
 
‘The conversations around the [risks of] myocarditis and pericarditis might take a bit longer. Getting kids vaccinated outside of school hours could be challenging,’ Associate Professor Danchin said.
 
‘I also think needle distress or needle phobia is going to be more of an issue. We know among the adolescent group that needle phobia is huge … and I suspect that will become a big issue in primary school children as well.’
 
If vaccination for under-12s is ultimately approved in Australia, as looks likely, Dr Best also expects differences in the rollout for this younger cohort.
 
‘I think the challenges for GPs are going to be very significant,’ he said. ‘We’ve already seen a huge amount of debate and emotion about vaccination rolled out in adults who are at much higher risk of COVID complications than children.
 
‘As with all things in medicine, health issues are always emotional, but health issues in children are really emotional.
 
‘We also have issues like transmission within education environments.
 
‘This is a very complicated decision, and I have every confidence that the regulatory authorities that are making those decisions are across all of those issues.’
 
While that process continues in Australia, Associate Professor Danchin says the most important protection for the younger age group comes from the vaccination status of the adults around them.
 
‘We want to encourage parents of primary-school-aged children not to wait for the vaccine,’ she said. ‘We believe that everything is being done to make schools as safe as possible.
 
‘The best thing parents can do is get vaccinated themselves.’
 
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