OR How to approach the risk/benefit discussion of COVID-19 vaccination in younger children
There is no doubt that vaccination is one of the most successful public health interventions. However, the risks and benefits of COVID-19 vaccination in children are more complex than other childhood immunisations. These need to be continually re-evaluated with the emergence of new variants, and new data on vaccine effectiveness and side effects. Generally, children infected with COVID-19 will have a mild illness, with severe disease (hospitalisation, death) and long-term morbidity being rare and children with underlying comorbidities being most at risk. There is also, however, a new inflammatory condition seen post-COVID, PIMS-TS / MIS-C, which has a peak median incidence of 9 years of age, that also needs to be incorporated into this risk-benefit discussion. A single dose of a COVID-19 vaccine appears to effectively reduce the risk of PIMS TS in adolescents. Data in younger children is pending.
We have all experienced the challenges of a constantly evolving ball game. Staying on top of the evolving literature and changing recommendations can be difficult. One of the challenges I have recently faced, as a clinician, is knowing how to approach best the risk/benefit discussion around COVID-19 vaccination in younger children (under 12) and then knowing where to direct families for further information. Here are some of the common questions I am facing working in a Paediatric Immunisation Centre at a tertiary paediatric hospital and some of the helpful resources I have been using.
What are the current recommendations for COVID-19 vaccination in children?
Comirnaty (Pfizer) and Spikevax (Moderna) are the only two vaccines provisionally registered in Australia for use in children and adolescents under 18. For further information on vaccines available, vaccine efficacy and common side effects, see here.
How should I approach the risk/benefit discussion of COVID-19 vaccination in children?
Benefits
Since phase III clinical trials, over 7 million children aged 5 to 11 have received two doses of mRNA COVID-19 vaccines. Data has demonstrated a similar safety and efficacy profile in younger children as in adults. With the emergence of new variants, vaccines provide some protection against milder infection and transmission. Protection against severe disease—hospitalisation and death—has also been maintained.
Whilst most younger children, without comorbidities, will have a mild infection and won’t require hospitalisation, they remain susceptible to other complications from COVID-19 disease, such as PIMS-TS/MIS-C, even after a mild or asymptomatic infection. A single dose of a COVID-19 vaccine effectively reduces the risk of PIMS-TS in adolescents.
Risks
Most side effects associated with these vaccines are mild and transient and last less than 72 hours. They include injection site pain, redness/swelling, fatigue, fever, headache and muscle pain. Severe side effects, such as anaphylaxis and myocarditis, are rare.
Myocarditis is a known but rare side effect of the mRNA COVID-19 vaccines. It is typically associated with the second dose and adolescent boys. Those aged 12-17 years are most at risk. Local and international data suggest that children under 12 are at a lower risk following mRNA COVID-19 vaccination (1 in a million doses).
Some common questions from families and how to deal with them
“Doctor, why does my child need to be vaccinated against COVID-19 when it is a mild illness for them?”
Although kids may have milder symptoms compared to older members of the population, they are still susceptible to other complications arising from COVID-19 disease, such as PIMS-TS/MIS-C. As the number of cases of COVID in the paediatric population increases, the number of those with these potential complications also increases. Vaccination, in combination with public health measures, may help to prevent them by reducing transmission and spread, and hence the overall case number in the extended family, school and general population.
“Doctor, I know plenty of vaccinated people who still got COVID-19; how effective is this vaccine?”
Whilst the vaccines do provide protection against infection, the main benefit of the COVID-19 vaccine is to prevent severe disease (hospitalisation and death) and the complications of SARS-CoV-2, such as PIMS-TS/MIS-C. As new variants emerge, the available vaccines have been less effective in preventing mild respiratory symptoms, though protection against severe disease is maintained. A single dose of a COVID-19 vaccine appears to be effective in reducing the risk of PIMS-TS in adolescents.
“Doctor, I keep hearing about side effects associated with these COVID-19 vaccines, how safe are these vaccines for young children between 5 and 11 years?”
Vaccination for kids between the ages of 5 and 11 is safe. Real-world data from the many millions of doses given shows no signal of adverse safety effects so far, and children are experiencing fewer significant adverse events than the older population.
Most side effects seen in children after vaccination are expected ones that signal that their immune system is building up protection. These include pain, redness and swelling at the injection site, and generalised symptoms such as muscle pain, chills, fever and tiredness.
Initially, there was a concern that myocarditis and pericarditis may also occur after mRNA COVID-19 vaccination in the 5-11-year-old age group. Data from the United States, where over 7 million children in this age cohort have been fully vaccinated with two doses, shows that the incidence is extremely rare, around 1 case per million doses.
As is the case for all vaccines, the safety of all our COVID-19 vaccines will be closely monitored locally by jurisdictional vaccine safety services in collaboration with the Therapeutic Goods Administration (TGA). The Australian Technical Advisory Group on Immunisation (ATAGI) also reviews data around any safety concerns and incorporates them into its clinical advice/ vaccine recommendations.
“Doctor, what about this inflammatory heart condition I keep hearing about?”
Myocarditis and pericarditis are inflammation of the heart muscle or heart lining. There have been an increased number of cases – above the expected population rate – of both conditions in individuals who have received mRNA COVID-19 vaccines. Young males (particularly those between 12-17 years of age) are at most risk, with 11 cases per 100 000 Comirnaty doses and 16 per 100 000 Spikevax doses compared to 1-2 cases per 100 000 Comirnaty/Moderna doses in older ages. There has been concern that the risk of myocarditis may also extend to younger children. Local and international data do not suggest a similar safety concern for children aged 5-11 receiving a COVID-19 vaccine.
Are there any good resources for families?
To review what the TGA knows about Australian myocarditis and pericarditis cases, review the latest COVID-19 safety report here.
For further information on Myocarditis following COVID-19 mRNA vaccines, including video resources for families, see here.
“Doctor, can you vaccinate children younger than 5 years of age?”
No, not at this time. However, Moderna recently announced interim data from its KidCove COVID-19 vaccine study in children 6 months to 6 years of age showing similar efficacy and safety as older children/adults using a quarter of the adult dose (25 micrograms). Pfizer is still undertaking trials in children from 6 months to 5 years of age to evaluate the safety and efficacy of its vaccine. We anticipate that we should have preliminary data soon.
Interestingly, all mRNA vaccines are considering using reduced doses for children under 5/6 years of age, as they clearly have an amazing immune system.
Children are not mini-adults, and it is important we have information on the safety, dose of vaccines and how they interact with their immune system before we start using these vaccines in younger children.
“Doctor, my child is about to turn 12. Should I wait until they can get the adult dose?”
No, there is no major difference between the immune systems of an 11-year-old and a 12-year-old. If your child turns 12 after their first dose of the Pfizer vaccine (using the 5-11-year dosing), then they can get the adult dose for their second dose when they turn 12.
“Doctor, why are some countries not recommending vaccination in healthy children?”
Some countries are still struggling to access and roll out vaccination. There is no doubt that vaccinating younger children is a privilege when there are more vulnerable populations around the world who remain unvaccinated. Younger children (particularly those younger than 12 years) have lower rates of severe disease than the elderly. However, we know that children can still have severe disease, particularly at-risk groups with underlying medical problems. We also know that there are children who are at risk of a serious inflammatory condition (PIMS-TS/MIS-C) that can cause damage to the heart following an asymptomatic or mild COVID-19 infection. Real-world data from many millions of doses has also shown no adverse safety signals, and, in particular, younger children do not appear to be at risk of myocarditis related to mRNA COVID-19 vaccines.
“Doctor, I heard that these mRNA vaccines can alter your genome”
No. Vaccine mRNA can’t integrate into an individual’s own DNA. mRNA from vaccines cannot enter the nucleus of a human cell (where a person’s genetic material is stored). It is also not possible for vaccine mRNA to turn into DNA. mRNA from COVID-19 vaccines only provides the code for part of the pathogen (e.g., the spike protein on the outer surface of a SARS-CoV-2 virus), not the whole pathogen.
For more information refer to CHOP: Can mRNA vaccines alter a persons DNA?
“Doctor, what is in this vaccine?”
Each COVID-19 vaccine contains slightly different ingredients. The full ingredient list of each vaccine can be found online under product information.
These ingredients are present in very small quantities and cannot cause you harm unless you have a severe allergy to an ingredient).
In general, COVID-19 vaccines are made up of the following:
None of the approved COVID-19 vaccines in Australia contain adjuvants. They are only found in certain vaccines to invoke a stronger immune response. The current Australian-approved COVID-19 vaccines do not contain animal products (like gelatin).
Further product information for each vaccine can be found here:
“Doctor, I heard that hese COVID-19 vaccines can cause infertility”
There is no evidence currently to suggest that any vaccine, including COVID-19 vaccines, can cause male or female infertility.
Participants in both the vaccine and placebo groups became pregnant at similar rates during vaccine clinical trials.
Vaccination of women who are planning a pregnancy is safe, effective and strongly recommended.
“Doctor, can my child have the Novavax vaccine ? How is it different from the other vaccines available in Australia?”
No, Novavax (Nuvaxovid) is currently only available for those aged 18 years and older.
See below regarding the currently available COVID-19 vaccines and how they differ.
Where can I go for further information? (including information for families)
Information specific for children
- CDC Report on effectiveness Comirnaty (https://www.cdc.gov/mmwr/volumes/71/wr/mm7109e3.htmPfizer) in preventing COVID-19 hospitalisation (March 4, 2022)
- CDC Report on effectiveness of Comirnaty (Pfizer) in preventing COVID-19 infection in children (March 18, 2022)
- CDC Report on effectiveness of Comirnaty (Pfizer) against MISC-C (January 14, 2022)
- CDC Report on hospitalisation of children 5-11 years (April 22, 2022)
- MVEC COVID-19 Vaccination in Children
- MVEC Immunisation Hub for the General Public
- NCIRS Decision aid: Should I get the COVID-19 vaccine (5-15 years)
- NCIRS Decision aid: Should I get the COVID-19 vaccine (16+)
- Raising Children Net: COVID-19 vaccination and children: 5-11 years
- The Royal Children’s Hospital Melbourne COVID-19 and Kids Resource Hub
Information for all ages
- ATAGI recommendations and updates
- MVEC COVID-19 page
- MVEC Immunisation Hub for the General Public
- NCIRS Decision aid: Should I get the COVID-19 vaccine (16+)
Information on COVID-19 vaccine safety
- CDC report on COVID-19 Safety in Children Aged 5-11 years (December 31)
- MVEC COVID-19 vaccine FAQ: vaccine development, safety, effectiveness and storage
- MVEC Myocarditis and pericarditis following COVID-19 mRNA vaccines
- TGA COVID-19 vaccine weekly safety report
References
https://www.tga.gov.au/reporting-suspected-side-effects-associated-covid-19-vaccine
Levy M, Recher M, Hubert H, et al. Multisystem Inflammatory Syndrome in Children by COVID-19 Vaccination Status of Adolescents in France. JAMA. 2022 Jan 18;327(3):281-283.
Zambrano LD, Newhams MM, Olson SM, et al. Effectiveness of BNT162b2 (Pfizer-BioNTech) mRNA Vaccination Against Multisystem Inflammatory Syndrome in Children Among Persons Aged 12–18 Years — United States, July–December 2021. MMWR Morb Mortal Wkly Rep 2022;71:52–58. DOI: http://dx.doi.org/10.15585/mmwr.mm7102e1
