First posted 16/1/2022, last updated 21/1/2022
MBBS, MAppFin, GradCertPubHlth, FRACGP, FACEM
Dual trained Specialist Emergency Physician & General Practitioner
Clinical Senior Lecturer, University of Western Australia
In Australia the Pfizer COVID-19 vaccine has recently been approved for children aged 5-11 y.o. However many parents I speak to still have questions regarding whether or not to vaccinate their child?
After all, COVID-19 generally causes a mild illness in this age group and parents have legitimate concerns about rare serious side effects. I too shared these same concerns for my child, so I decided to look at the latest data myself, including data released after the vaccine was approved, before making an informed decision.
I’ve provided a brief summary at the start, with the full detail following.
Summary
- In this age group, COVID-19 infection is generally a mild self resolving illness but very occasionally complications occur. A condition known as “Long COVID” encompassing a range of symptoms can persist post infection and last over 3 months. This complication is common in adults but the frequency of this condition in children is not well established and it is likely less severe in children. In terms of rare, serious complications, about 1 in 3,200 children infected with COVID-19 develop a widespread inflammatory condition weeks after a COVID-19 infection which ranges from mild to life threatening. Also up until December 8th 2021, 1 child in Australia in this age group (who had underlying health conditions) has died from COVID-19 at a time when Australia had a relatively small number of total COVID infections compared to other countries.
- Serious risks from the Pfizer vaccine in this age group, including myocarditis and pericarditis, are almost non-existent. Further, Australian medical authorities have taken steps to reduce this rare risk even more by spacing out the interval between 1st and 2nd doses to 8 weeks for this age group specifically.
- The vaccine reduces COVID-19 infection in this age group by 90% and will likely be partially effective against newer variants like Omicron (although data is not yet available on the latter).
- Vaccination of this age group may reduce the risk of the following: COVID-19 infection in other family members, community spread, school closures (home schooling), family isolation & quarantine and community wide lockdowns. These events can have adverse mental health and health consequences for children and families. Any reduction in community spread would reduce the risk of the Australian health system becoming severely overwhelmed. If this occurred, this would generally increase the risk of death and serious complications in all patients (COVID and non-COVID patients).
- In summary, while the risks of COVID-19 infection in this age group are generally small, rare serious outcomes do occur and by comparison serious risks of the vaccine are almost non-existent. Additionally, the benefits of vaccination to the children, families and the wider community are collectively potentially profound.
- I too had initial concerns about whether it was worth vaccinating my child in this age group but the latest data now based on millions of vaccinated children is very reassuring and supports well established scientific principles. In these times, life is tricky as we often need to make important decisions based on incomplete information. We need to combine the best evidence we have with scientific biological plausibility to make the best decisions we can. Doing so, leads me to believe that vaccinating my child is preferable to not vaccinating them. Consequently I have decided to vaccinate my child in this age group with the Pfizer vaccine.
What are the risks of COVID-19 Infection?
Regarding COVID-19 in this age group, it is true that it is generally a mild, self-resolving illness. However :
- Children in this age group accounted for about 1 in 2,500 of the Intensive Care Unit admissions that occurred in Australia between June and October (during the delta outbreak).
- From the relatively small number of cases of COVID-19 in Australia reported before 8th December (compared to other countries) 1 death has been reported in this age group, albeit in a child with significant underlying health problems.
- Children infected with COVID-19 can develop a significant inflammatory disease called Paediatric Multi-system Inflammatory Syndrome 2-6 weeks after COVID-19 infection. This disease can range from mild to life-threatening in severity and occurs in 1 in 3,200 children who contract COVID-19 infection.
- A condition known as “Long COVID” consists of a wide array of symptoms that can persist for over 3 months following COVID-19 infection. While this has the potential to be debilitating, and is a common complication in adults, studies on the frequency in children are limited but suggest that this is usually less severe and shorter duration in children.
- Children with certain co-existent medical problems including obesity are at significantly higher risk of severe illness and death from COVID-19 infection
- Note that with open borders and normalised travel it is expected that COVID-19 exposure will be unavoidable for adults and children.
What are the risks of the vaccine?
- Firstly, conceptually it is worth noting that because they are smaller, children in this age group only receive ⅓ of the dose that adults receive of the Pfizer vaccine to optimise safety.
- Mild transient symptoms like pain at the injection site, fatigue and fever are similar to adults and not of real concern. It is the rare, serious side effects that legitimately worries most parents. The only rare and potentially serious complication of note associated with the Pfizer vaccine in older children aged 12-17y.o is myocarditis and/or pericarditis (explained in the next section, and hereafter referred to as myopericarditis) which occurred in approximately 40 per million doses and was higher after the 2nd dose (60 per million doses).
- From the United States we now have substantial safety data. As of Dec 31st 2021, after the delivery of 8 million doses of Pfizer vaccine to 5-11y.o’s, only 11 cases of myopericarditis have been reported. This is a roughly 1 in a million risk!* This is consistent with the observation that the background risk of myopericarditis (the rate of myopericarditis that usually occurs in that population in the absence of COVID-19 infection) is lower in younger children compared to older children.
- Canadian studies of older children revealed that the rate of this complication post vaccine is even lower in those who had 8 weeks or more between their 1st and 2nd dose of vaccine. Consequently Australian medical authorities have taken the sensible precaution of recommending 8 weeks between 1st and 2nd doses with the expectation that this complication will be even less likely than that observed in the US where only 3 weeks were given between doses.
- To further put these minute risks into perspective, note that this myopericarditis complication can just as easily occur from contracting COVID-19 infection itself. In fact some official sources estimate the risk of myopericarditis to be at least 30 times higher in children who contract COVID-19 compared to those without infection.**
Is the rare myocarditis complication from the vaccine actually a big deal?
The first thing to know is that this is not a heart attack! Myocarditis means inflammation of the heart muscle and pericarditis means inflammation of the sac that surrounds the heart (not the heart itself). They can occur separately or in combination and are often referred to collectively as myopericarditis.
Aside from this being an exceedingly rare side effect in this age group, even if it occurred, this is usually easily diagnosed or excluded in an Australian Emergency Department. Children usually present with chest pain, shortness of breath or palpitations and with modern medical care and monitoring it is rarely ever actually life threatening. The condition usually self resolves within weeks though can occasionally result in some (usually milder) symptoms for months. Additionally, available data suggests vaccine induced myopericarditis is a milder condition with better outcomes compared to classical myopericarditis.
In summary, my child has almost no risk of incurring a potentially serious condition (if untreated) due to the vaccine (which is more of an issue from infection itself anyway) that is usually easily managed within the Australian healthcare system with generally an expectation of full recovery within weeks.
How much evidence do we really have that the vaccine is safe? Should I wait longer?
- In general, most new medications that Australians are usually happy to have prescribed for themselves and their families are tested in clinical trials on only thousands of people which provides excellent data on common and uncommon side effects but can miss out on capturing rare side effects. This is the case with the initial trial of Pfizer on children aged 5-11y.o.
- However in Australia, we are fortunate to be able to observe real world evidence from the vaccination of millions of children in the United States to provide the above estimates of rare side effects before making decisions. Already more children in the 5-11y.o age group in the United States have been safely vaccinated, than actually exist in all of Australia. This is extremely reassuring!
- Importantly this safety data is not at all surprising. It merely supports what we already know and expect from vaccines – specially designed vaccines that effectively deliver just one small carefully chosen part of a virus in order to activate the immune system (without causing infection) is far safer than contracting a full blown infection from the entire viral particles. Vaccines are not without any risk, but risks we observe are expected to be far less severe or common with the vaccine than from the disease itself. This theoretical expectation is not an iron clad rule and rarely exceptions do occur, but in this case, the data reassuringly supports that expectation for the Pfizer COVID-19 vaccine in this age group.
- Some parents have concerns regarding whether there are late onset side effects from vaccination that we don’t yet know about that could occur many months or years post vaccination. Regarding this very reasonable concern:
- This is unlikely because the mRNA injected into human muscle (the Pfizer vaccine) is broken down within hours or days by the human body. Consequently any side effect from the vaccine is likely to occur within days due to the mRNA itself or within the first few weeks due to the immune system reaction to the COVID viral proteins produced by our muscle cells from the mRNA.
- It is notable that so far in adults no late onset vaccine reactions have been established despite vaccinating many hundreds of millions of people.
- We don’t have the luxury of waiting 10 years for long term data. Rational decisions need to be made now based on the available data and scientific biological plausibility. As explained above, biological plausibility suggests that in the very unlikely event that any late onset reactions were to occur, they would likely be more severe and frequent from COVID-19 infection than from vaccination. This scientific biological plausibility is supported both by the above evidence regarding short term complications from this vaccine and our long established experience with vaccine science historically.
What are the benefits of the vaccine?
The direct benefit of vaccination for this age group is evidence that it reduces their risk of COVID-19 infection by 90%. The effectiveness against newer variants like Omicron is unknown but it is likely to be partially effective.
The indirect benefits of vaccination include a lower risk of school closures (home-schooling), as well as a probable reduced risk of infection of family members such as adults (whether vaccinated or not) and children under 5 years old who can’t currently be vaccinated. This reduces the risk of parental absenteeism, serious illness of family members and isolation and quarantine for the family.
It is also probable based on modelling (but not proven) that vaccination of this age group will help reduce COVID-19 community spread which in turn would reduce the risk of community wide lock-downs, industries paralysed by absenteeism & isolation requirements and severely overwhelmed medical facilities. Such a compromised health system would increase the risk of death and serious illness in all patients (COVID and non-COVID patients) as they would no longer be able to receive timely and optimal care for their health problems.
School closures, significant family illness, isolation/quarantine and lockdowns can have significant adverse mental health and health consequences for children and their families.
It is true that both the direct and indirect benefits of the current Pfizer vaccine will likely reduce to some degree as community exposures change from alpha to delta to omicron variants. The exact extent of that reduction is currently unknown but it is unlikely that these benefits will be eliminated.
Conclusion
In summary, I find that while the risks of COVID-19 infection in this age group are indeed small, rare serious outcomes do occur and by comparison serious risks of the vaccine are almost non-existent. Additionally, the benefits of vaccination to the children, families and the wider community are collectively potentially profound.
I too had initial concerns about whether it was worth vaccinating my child in this age group but the latest data now based on millions of vaccinated children is very reassuring and supports well established scientific principles . In these times, life is tricky as we often need to make important decisions based on incomplete information. We need to combine the best evidence we have with scientific biological plausibility to make the best decisions we can. Doing so, leads me to believe that vaccinating my child is preferable to not vaccinating them. Consequently I have decided to vaccinate my child in this age group with the Pfizer vaccine.***
More Information & References
- Australian Guidance on vaccinating children in this age group:
- Simplified and summarised by the NCIRS (20/12/21)
- Detailed information from ATAGI (8/12/21)
- This provides a good discussion of the risk/benefits of COVID Vaccination versus COVID infection
- Canadian data on rates myocarditis/pericarditis from mRNA vaccines.
- Demonstrated the lower rates of this complication when the vaccine doses were given ≥ 8 weeks apart.
- US CDC Data
Footnotes
* Passive monitoring systems that were used to produce the real world data above (demonstrating 1/million riks), can sometimes underestimate the true risk as some cases of myopericarditis may not be reported. However it is exceedingly unlikely that this underreporting would be of such a severe magnitude to make this minuscule risk a relevant consideration. Notably also in the active monitoring of a smaller but still substantial group of 330,000 children, zero cases of myopericarditis were detected. Additionally, this same real world data passive monitoring by the CDC correctly estimated the risk of myopericarditis in older children when compared to estimates from other countries. Collectively, this suggests significant underreporting of complications in this data set is very unlikely.
**COVID-19 patients with minimal or no symptoms often don’t get tested and are therefore not all captured in studies, so the true increased relative risk of myopericarditis from COVID-19 infection, is likely to be substantially lower than that reported figure of 30 times greater risk. Nevertheless, myopericarditis is clearly a complication that is likely significantly more common from COVID-19 infection compared to Pfizer vaccination in this age group.
*** Please note while this article helps answer the question of whether to vaccinate a child in this age group, it doesn’t answer the question of whether to vaccinate children before opening schools. That requires a rational balancing of the net vaccine benefits against the substantial harms of school closures.
Article Updates
21/1/22:
- Added to the information regarding late onset vaccine reactions to improve explanation and included discussion of scientific biological plausibility
- Then moved the information to the section on vaccine safety.
- In the Vaccine Benefits section, edited language regarding indirect vaccine benefits and added a statement about reduction in vaccine benefits against newer variants.
- Edited Conclusion and Summary in line with above