resounding success, showing over 90% effectiveness. Another extraordinary aspect was how the vaccine underwent clinical trials and was delivered under almost impossible circumstances of remoteness and ongoing hostilities. The ERVEBO vaccine prevented the DRC epidemic from spreading across Central Africa and likely destabilizing the entire region.

Ebola demonstrated both the strengths and weaknesses of our global vaccine infrastructure. On the positive side was the proof of concept that it was possible to develop and deploy a new vaccine for an imminent global health threat even in the middle of a raging epidemic. On the negative side was that as international attention focused on Ebola virus infection, measles erupted in the DRC and wound up killing more Congolese than Ebola. The global vaccine ecosystem is a fragile one. Along those lines, measles reemerged in multiple countries due to interruptions in vaccination programs resulting from political instability or conflict. Still another driver was a rising antivaccine movement that caused measles to return to Europe, the United States, and worldwide. Operating primarily through the internet and social media, antivaccine activities now threaten to reverse 2 decades of steady successes under the auspices of the UN-sponsored Millennium Development Goals.

All these events culminated in the global coronavirus disease 2019 (COVID-19) pandemic. The COVID-19 pandemic of 2019-2023 or longer, shows the interface between virology, vaccinology, and epidemiology, with societal inequity factors and the urgencies of political awareness and national security. Beginning in Wuhan City, Hubei Province, China, under unclear circumstances, the virus spread quickly into Southern Europe and then to the United States and Brazil. In 2020, COVID-19 became the leading infectious disease killer globally, while in some countries, such as the United States, COVID-19 led all causes of death daily for much of 2020. Like Ebola, COVID-19 revealed the best and worst of global public health. A multinational response was launched to promote the development of new vaccines, including some with cutting-edge mRNA technologies, advancing the field of vaccinology. Conversely, COVID-19 spread aggressively in countries led by populist regimes whose leaders attempted to dismiss its severity or even encouraged outright defiance of nonpharmaceutical interventions like wearing face masks, frequent hand-washing, and social distancing. In parallel, there were breakdowns in the global governance of vaccines despite the best efforts of UN agencies and the Coalition of Epidemic Preparedness Innovation to establish mechanisms for equitable vaccine access. A new term, “vaccinationalism,” was coined to reflect bilateral agreements led by Russia or China to sell or distribute COVID-19 vaccines directly to resource-poor countries as the United States attempted to declare eminent domain over the vaccines produced by multi- nationals. Not since HIV/AIDS first emerged in the 1980s was an illness so directly tied to political agendas.

This latest and fourth edition of The New Public Health textbook provides the fundamentals and foundations comprising the core elements required for public health systems to be strengthened and ready for long-term development, as well as for crises, such as the coronavirus pandemics of recent decades. I congratulate Professors Tulchinsky, Varavikova, and Cohen for preserving this critically important canon and their adaptability and willingness to explain the profound shifts in public health arising since the third edition over these last few years.

Peter J. Hotez, MD, PhD, DSc (hon), FASTMH, FAAP