The emergence of a novel coronavirus in 2019 has changed our world in ways few could have imagined. Soon it would spread to almost every part of the world. Millions would die, everyday life would come to a halt, and governments would take previously unimaginable measures. These events reversed long-standing improvements in global health, impacting disproportionately those already disadvantaged.

The COVID-19 pandemic is only one manifestation of what has been described as a syndemic. Multiple interconnected phenomena are posing unprecedented threats to health worldwide. Global warming is changing our world, creating shortages of water, expanding deserts, and causing increasingly frequent extreme weather events such as hurricanes, heat waves, and floods. Conflicts and wars, often driven by the quest to control valuable natural resources and wider geopolitical developments, are devastating communities. The resulting food shortages and insecurity, displacement of populations, and loss of biodiversity create the ideal conditions for novel microorganisms to emerge and spread. For the first time in history, human activity is threatening the survival of our species.

The COVID-19 pandemic shone a light on the deep fractures that have weakened our societies. There are always those ready to exploit a crisis, the profiteers, corrupt officials, and peddlers of disinformation. While most politicians and the media celebrate the signs of growing affluence, they ignore those who are left behind. The people who are often effectively invisible, leading precarious lives, with many groups, often defined by their gender, age, sexuality, ethnicity, or migration status, unable to assert the rights that we believed were universal.

The pandemic revealed many institutional weaknesses. This was especially clear at the global commercial and financial agreements, such as the Trade-Related Aspects of Intellectual Property Rights (TRIPS), that protect patent monopolies and leave many countries in the global south unable to benefit from innovations such as the newly developed vaccines.

The increased diffusion, during the pandemic, of ‘fake news’, misinformation, disinformation and infodemics related to health and incorrect interpretations of health information negatively impacted people’s mental health, increased vaccine hesitancy and delayed the provision of healthcare.

Our world is in turmoil. Yet, there are opportunities. The pandemic did, however, provide grounds for optimism.

The scientific community stepped up to the challenge, working together above these divisions to address health and wellbeing problems. Public health workers provided guidance about preventive measures and shared information about how to respond to the disease as it spread globally. High-quality surveillance systems and contact tracing systems were put in place, with high-volume genomic sequencing enabling us to track the pandemic in real time. Clinical trials went from design to recruitment within days, providing vital evidence on what worked and what did not. Innovative vaccines were developed in record time. Health workers, often battling illness and exhaustion, redesigned models of care, while many other essential workers in education, social care, and logistics found new ways of working.

These opportunities, and the hope they offer, feature strongly in the 17th World Congress on Public Health (WCPH), organized by WFPHA, ASPHER and SITI, which has provided a setting for the global public health community to come together to look to a brighter future for all.

Firstly, we have been reminded of the importance of promoting equity. As public health professionals, we must never forget our role in giving voice to the poor, marginalized and discriminated.

Secondly, we have seen that action is now urgent. We are already seeing signs that we are reaching tipping points both in vulnerability to the rapid global transmission of infectious diseases and in the impacts of the climate crisis manifest in melting polar ice caps and loss of tropical forests risk. We simply cannot delay. As humanity, we must develop new relationships and ways of working with each other and with the animals and plants with whom we share this small and vulnerable planet, relationships that build on our mutual dependence and create equitable and sustainable solutions across future generations.

Thirdly, we have seen how, even in the most severe crises, not everyone is on the same side. Many of our current problems arise from the exercise of the power possessed by certain financial and political interests, groups that have worked to ensure that they are largely unaccountable in a system of weakened global governance. The public health community cannot let up in the struggle to expose and counter those who use their power to threaten health.

Fourthly, we have been reminded of the importance of peace, which, as the Ottawa Charter noted, is a fundamental prerequisite for health. The scale of human suffering created by contemporary conflicts must lead to a new international order that can hold aggressors to account for and prevent future disputes. This is more important than ever as some countries reverse previous progress in nuclear threat de-escalation.

Fifthly, we must take full advantage of the opportunities presented by scientific progress. These include advances in technology for preventive measures, vaccines, treatments, and the digital revolution, with its scope for new approaches to gathering, synthesizing, and using data while ensuring the necessary safeguards to prevent abuse that can lead to iatrogenesis, privacy violation, and misinformation.

Sixthly, we must counteract false information on health and its determinants. The effects of infodemics and health misinformation online can be countered by ‘developing legal policies, creating and promoting awareness campaigns, improving health-related content in mass media and increasing people’s digital and health literacy’, as highlighted by WHO.

Seventhly, we want to underline the basic role of health promotion workers to achieve the goal of health in and for all policies as part of the indispensable interdisciplinary and multisectoral approach. We have particular regard for health promotion and building physical and social environments that protect and promote health to have healthy behaviors, healthy and safe housing, and ensure adequate access to healthcare.

Finally, the syndemic nature of contemporary health crises demands that we, as public health workers, work together across sectors, seeking opportunities to realize co-benefits where everyone wins and so better address current challenges. This is the only way we will achieve the Sustainable Development Goals that are essential for our survival.

Whether on a global, national or local level, the public health community has been intensely dedicated to addressing health issues and fighting the COVID-19 pandemic was an example of that dedication. In health services, public health workers guided protective and preventive measures. In universities and research centers, they trained people and produced knowledge essential to overcoming the critical situation. In non-governmental organizations, public health workers mobilized citizens in favor of the universal right to health and advocated for health equity. Everywhere we are aware that public health cannot be anything but political.

The 17th WCPH provided for PH professionals from across the globe to come together to share experiences, highlight the learnings and progress made, document emergent PH competencies and focus on the lessons learned for the future. Moreover, so much is at stake that we will intensify our efforts to protect people and the planet by advancing public health knowledge, research, education, and practice and advocating for peace and sustainable, equitable health and development.