Child-centred pandemic decisions: how the Precautionary Principle can generate better risk assessment in an era of uncertainty

Key messages Risk assessment for children has been a polarising issue during the Covid-19 pandemic. Governments around the world are preparing to ‘open up’ before risks to children are fully quantied, with unknown implications for their long-term health. Applying the Precautionary Principle to child health requires decision makers to 1) take preventive action until risks are better understood; 2) ensure that the burden of proof rests with proponents of risk; 3) explore alternatives to the risk; and 4) use participatory approaches to decision-making. Policies relating to children must be centred on the rights and wellbeing of children. We provide a framework for comprehensive Health Impact Assessments to ensure that direct and indirect impacts upon children are taken into account in major policy decisions. Elimination strategies offer an integrated approach to the protection of children’s wellbeing, the wellbeing of the population as a whole, and health equity. Where countries are transitioning away from elimination, a tight suppression approach is preferable to loose suppression or mitigation.


Introduction
Risk assessment for children (ie, those aged under 18 years) has been a contentious and polarising issue during the pandemic. Aotearoa New Zealand has generally avoided engaging with these controversies because its elimination strategy signi cantly reduced impacts on children from both Covid-19 infection and the control measures used to contain it. Currently the country is experiencing its rst Delta-variant outbreak at a time when its children are still largely unvaccinated and immunologically naïve to SARS-CoV-2.
Our analysis uses a structured approach to consider the proper place of children in pandemic decisions.
The Precautionary Principle is often invoked without de nition or explanation of its implications. To address this gap, we identify four key elements of the Precautionary Principle and explore their relevance to children in the pandemic, guiding strategic and operational decisions in the presence of high uncertainty. We provide a framework for comprehensive Health Impact Assessments to ensure that direct and indirect impacts upon children are taken into account in major policy decisions. We use the example of Aotearoa New Zealand as a country at the brink of key decisions about its pandemic strategy and its child population.

Children and the SARS-CoV-2 pandemic
The initial perception that children experienced minimal illness from Covid-19 infection has evolved into a more complex picture that includes evidence of signi cant harms to children. These harms may be direct (arising from being a case) or indirect (arising from community transmission with impacts on non-Covid healthcare and health equity). Added to these harms from the virus itself are the impacts of the pandemic response (ie, control measures); again, these harms may be direct (educational disruption from school closures) or indirect (increased prevalence of child poverty when employment is insecure).
The wellbeing of children should be central to pandemic policy decisions. In Aotearoa New Zealand, similarly to other Indigenous cultures, Māori health perspectives support individual wellbeing but there are also beliefs around collective wellbeing that are linked to Māori self-determination. 1 Tamariki Māori (Māori children) must not be seen alone in matters of health and wellbeing, but always centred in the context of their whānau/family. They are seen as gifts from the atua (spiritual beings) and from the tipuna (ancestors), requiring societies to provide nurturing environments to support them to achieve their potential. 2 This collective model of wellbeing aligns closely with a population health approach, 3 providing the basis for an integrated assessment of the linked effects of the pandemic on children, families, and communities. 4 Decisions need to be centred on child wellbeing to protect children from direct and indirect harms of the pandemic and the response. Jurisdictions should avoid using children as a means to an end such as population immunity to Covid-19 whether via vaccine or disease. 5 The Precautionary Principle as a decision framework for children and the pandemic The Precautionary Principle is a decision framework intended for situations of high uncertainty where decisions have signi cant impacts. Our analysis of children's place in the pandemic is structured around four key elements of the Precautionary Principle: 6 1. Take preventive action until risks are better understood; 2. Ensure that the burden of proof rests with the proponents of risk; 3. Explore alternatives to the risk; and 4. Use participatory approaches to decision-making.
We consider the implications of each principle for Covid-19 pandemic decisions. Principle 1: Take preventive action while novel risks are being characterised and quanti ed By de nition an elimination strategy prevents more transmission, illness, disease complications, and death from Covid-19 than other pandemic strategies, simply because it prevents more cases. But because having no community transmission allows for fewer pandemic restrictions, elimination has also prevented many of the adverse consequences of lockdowns and overwhelmed health systems experienced by jurisdictions attempting mitigation or suppression. 7 8 An elimination strategy provides time to learn from the experience of other jurisdictions, implementing policies that have been shown to be successful elsewhere while avoiding policy failures. Two examples where Aotearoa has learned from international experience include evidence about vaccination safety and e cacy in children, and observing the stark health inequities experienced by children in marginalised populations.
Principle 2: Ensure the burden of proof rests with the proponents of risk Proponents of Covid-19 endemicity ('living with the virus') have a responsibility to be transparent regarding the ongoing health and social costs of this strategy at a population level. Endemicity is often confused with mild disease and normal life, but many common endemic diseases (eg, malaria) cause high morbidity and mortality in children. Poliomyelitis, another disease that was endemic in most of the world until recently, is asymptomatic in around 70% of infections and only rarely causes paralysis. But tolerating endemicity is not an accepted strategy for polio because the high transmissibility of this infection (R 0 around 10 9 ) results in large numbers of cases, leading to a high and unacceptable health burden in unvaccinated populations.
The same phenomenon can be seen in Covid-19 outbreaks; when community transmission is high the absolute numbers of paediatric hospitalisations and of serious complications such as multisystem in ammatory syndrome of childhood (MIS-C) 10 are likewise high and can overwhelm health service capacity.
Similarly, the prevalence and duration of ongoing post-acute symptoms (eg, Long Covid) in children is yet to be clearly established but emerging ndings are concerning. 11 12 Life-altering post-acute effects have been observed in most childhood infectious diseases and in both of the previous coronavirus pandemics. 13 Decision-makers advocating against the use of Covid-19 vaccines or other preventive measures for children need to demonstrate evidence for beliefs that the SARS-CoV-2 virus will be more benign compared with these other infections.
Principle 3: Explore alternatives to the risk The three main strategies for a pandemic of moderate-to-high transmissibility and severity are elimination, mitigation, and suppression. 8 14 These approaches are described in Table 1, while the impacts of these Covid-19 strategies on children are compared in Table 2. Table 1. The three main Covid-19 pandemic strategies: elimination, mitigation, and suppression.

Pandemic control strategies
Pandemic options that are enacted at the country level are de ned by their aims. 8 14 Elimination aims to stop community transmission of the SARS-CoV-2 virus for prolonged periods within a speci ed country or region. Mitigation is a form of control that accepts transmission at a predetermined, manageable level, e.g. to avoid overwhelming the health system in an in uenza pandemic. Suppression aims to keep transmission at a low level to minimise adverse health effects, as for HIV/AIDS. Elimination strategies have been widely used in the Asia-Paci c region for control of  How is Covid-19 elimination experienced 'on the ground'? Elimination differs from mitigation or suppression in ways that go beyond differences in case numbers. Elimination starts from and returns to a baseline in which children experience relatively few restrictions in their daily lives, although stringent restrictions at the borders are necessary. Mitigation and suppression approaches allow more freedom to travel but accept a continuous and uctuating level of new cases, hospitalisations, and deaths.
Mitigation and suppression approaches require ongoing application of controls such as school closures and cancellation of routine healthcare to prevent health systems from becoming overwhelmed during peak transmission periods. Elimination requires a high stringency of outbreak control applied at an early phase of the epidemic curve, but once elimination is regained, controls are lifted. Paradoxically, jurisdictions pursuing Covid-19 elimination have spent less time under lockdown than jurisdictions aiming for mitigation or suppression ( Figure 1). • Rarely, severe complications include multisystem in ammatory syndrome (MIS-C) 10 • Post-acute impacts include persisting symptoms such as fatigue and cognitive di culties (e.g. Long Covid) 11 with pathological in ammatory changes at the tissue level observed in vital organs such as the brain. 12 The duration of persisting symptoms, incidence, and long-term impacts are not yet fully established but population impact may be substantial given the large number of children infected • Schools remain open for extended periods when community transmission is low or eliminated, minimising educational, health, developmental, and social harms from prolonged school closures.
• Elimination results in shorter time spent in lockdown than in jurisdictions using suppression or aiming for herd immunity.
Children are able to socialise with older members of their wider family and community, supporting child wellbeing and interconnectedness.
• Vaccines: Effective prevention of community transmission will require most children to be vaccinated. Aotearoa NZ has commenced vaccination of the 12-15 year age group. The FDA has approved vaccination in the 5-11 year age group and the results of vaccine trials in children aged 6 months to 4 years are awaited; • NZ's high stringency lockdowns eliminated transmission of a large number of respiratory and other infections during the winter of 2020. 19  • Children may however be negatively impacted through geographic separation from family members overseas due to border restrictions.
Health equity • The Covid-19 pandemic has widened pre-existing inequities over multiple domains.
• In countries with high levels of transmission, severity of disease is higher in children from low-income households and children with underlying chronic conditions. 20 Covid-19 hospitalisations are also strongly patterned by ethnicity, with particularly high incidence rates in Indigenous populations. 21 • In jurisdictions like Aotearoa where widespread Covid-19 infections are likely to widen pre-existing health inequities, elimination is pro-equity in its aims. However, the Alert Level 4 lockdown of 2020 caused substantial hardship for low-income families. This additional hardship was predictable and could have been mitigated through effective policy. 22 • Inequities in the pandemic response signal the need for policy design that is explicitly pro-equity. 23 In Aotearoa for example, Te Tiriti o Waitangi/ The Treaty of Waitangi must be upheld in all aspects of the pandemic response. [24][25][26] * Note that with a suppression approach, particularly if applied rigorously (ie 'tight suppression') the direct and indirect effects of disease will be less, but the direct and indirect effects of the response may be increased Principle 4: Use participatory decision-making The SARS-CoV-2 pandemic exacerbates existing structural inequalities and as noted in Table 2, these inequalities have had profound impacts on child wellbeing during the pandemic.
These ndings are in keeping with known inequities in infectious disease incidence in Aotearoa 27  Those that carry the most risk of adverse impacts must have a say in policy decisions. Such decisions need a national conversation and transparent policy processes, ensuring that decisions re ect the views of children and their advocates. In particular it is critical to ensure that commercial determinants of health (eg, pressure from tourism or hospitality industries) are not the deciding factors in Covid-19 policy relating to children.

Discussion
Decisions about children in the pandemic are currently being made in an environment of rapid change and high uncertainty. In many jurisdictions including Aotearoa NZ, governments' pandemic strategy decisions have not included mechanisms for considering the needs and rights of children. 29 The United Nations Convention on the Rights of the Child (UNCROC) guarantees rights for children and young people up to the age of 18 years. The Convention has been rati ed by all UN member states except the US, and was rati ed by New Zealand in 1993. Of particular relevance is Part 1, Article 6: "States Parties shall ensure to the maximum extent possible the survival and development of the child". 30 UNCROC needs to be seen alongside the Sustainable Development Goals 31 33 This wider perspective expresses a transformative goal for the health inequities experienced by disadvantaged groups around the world.
The Precautionary Principle recommends preventive action and exploring alternatives to risk while the evidence is unclear. This principle also requires participatory decision-making and self-determination in pandemic risk management. Prevention of Covid-19 transmission is equity-promoting in its intent, but pandemic control measures require careful design and implementation to avoid perpetuating existing health inequities. That means consistently upholding the rights and values of Indigenous Peoples, children, and other populations at risk of adverse outcomes.
Covid-19 elimination protects child wellbeing in multiple ways and allows time for the development and adoption of innovative approaches to improve pandemic outcomes. Where elimination is too challenging to implement, a high degree of suppression would be the second choice. As with other infectious diseases of public health importance, Covid-19 control requires a multi-layered approach that includes vaccination, public health and social measures, and outbreak control. These measures have co-bene ts as well as risks. For example, optimising air quality in schools holds promise for preventing transmission of Covid-19 and many other childhood respiratory infections, while improving children's learning and concentration. Such measures have potential to be a lasting and positive legacy of the pandemic.
Over time as knowledge accumulates, the Precautionary Principle can give way to a more conventional evidence-informed approach. Vital evidence to guide strategy will include robust prevalence and duration data on post-acute complications in children and young adults, information on the safety and e cacy of new vaccines in these age groups, and the development of effective infection control measures in schools to support safe in-person learning.

Conclusion
The precautionary approach analysis presented here indicates that elimination continues to be the optimal strategy for Covid-19 because it offers an integrated approach to the protection of children's wellbeing, the wellbeing of the population as a whole, and health equity. Elimination minimises both direct and indirect impacts upon children, and removes the requirement for children and adults to take on unquanti ed risks from this novel and incompletely-understood infectious disease.
Where countries transition away from elimination they must apply the precautionary principle for the health of children. In these circumstances, a tight suppression approach would be preferable to a mitigation strategy that allowed widespread infection of children with poorly quanti ed and potentially serious health impacts. However, a suppression strategy can also generate negative impacts on children through ongoing imposition of control measures, so those impacts need to be carefully managed.
Children's wellbeing is a special consideration because children are growing and developing: governments planning to allow a large proportion of their child population to be infected with a new pathogen need to consider the impacts that this decision may have on population health for decades to come. This paper provides a framework for a comprehensive Health Impact Assessment to ensure that direct and indirect impacts upon children are taken into account in major pandemic policy decisions. Such decisions must include the voices of children and their advocates.
The impacts identi ed in this analysis indicate the importance of minimising Covid-19 infection in the child population, bringing public health policy into line with the standard approach for other vaccinepreventable diseases of childhood. This precautionary approach should be the benchmark against which Covid-19 risks and policies are assessed.

Con icts of interests
There are no con icts of interest.
Contributorship statement AK has a dual background in clinical paediatrics and infectious diseases epidemiology, JR is a paediatrician and child health researcher, CTP (Ngāti Kahungunu) is a nurse and public health researcher, and MB is a public health physician with extensive expertise in infectious diseases research, including pandemic strategy and epidemiology.
AK initiated the idea of applying the precautionary principle to child wellbeing in the pandemic, and produced the initial draft. All other authors contributed content and critique to subsequent drafts. CTP also contributed content and concepts relating to Te Ao Māori (the Māori world), as a Māori researcher with child health expertise.

Figure 1
Stringency index illustrating sustained high stringency of jurisdictions pursuing mitigation or suppression (UK, US, and Sweden) compared with New Zealand's elimination strategy, using intermittent application of high-stringency control measures to extinguish outbreaks. The rst of the NZ peaks represents a national-level lockdown; the second and third were regional only; and the fourth commenced as a national lockdown but is now regional only. (Graph generated using the Oxford COVID-19 Research Tracker; https://ourworldindata.org/grapher/covid-stringency-index).