A Public Health Emergency of International Concern (PHEIC) is defined by the World Health Organization (WHO) as “an extraordinary event which is determined to constitute a public health risk to other states through the international spread of disease and potentially requires a coordinated international response”. To date, WHO has declared seven PHEIC events, including the H1N1 influenza, Ebola, poliomyelitis, Zika, COVID-19 and mpox. Vaccination remains as an effective method in preventing infectious diseases. The International Health Regulations (IHR) Emergency Committee's recommendations for preventing or reducing the international spread of disease and avoiding unnecessary interference with international traffic include an emphases on the development of diagnostics and therapeutics for diseases, as well as the vaccine development. The mRNA vaccine represents a platform technology for the development of next-generation vaccines, and possesses distinct advantages, such as a shortened development cycle, scalable and cost-effective production, as well as enhanced amplification capacity, highlighting its potential in rapid responding to emerging and re-emerging infectious diseases. In recent decades, the development of mRNA synthesis technology and nucleic acid delivery system has facilitated the rapid development of mRNA vaccines and their clinical applications. Here, we overview the development of mRNA vaccines in response to the past PHEICs, and discuss challenges and trends in this regard. Currently, COVID-19 mRNA vaccines have been authorized for human use, while multiple mRNA vaccines against influenza, Zika, mpox and Ebola have been evaluated in clinical or pre-clinical studies. Despite their proven efficacy, there is still room for further improvement of the mRNA vaccines. The mRNA design, optimization, delivery, formulation, manufacturing, storage, and transportation can be further improved by integrating synthetic biology, biochemistry, artificial intelligence, and other multidisciplinary technologies. Although the emergence of the next PHEIC cannot be predicted with certainty, we are optimistic that the mRNA vaccine technology will play a pivotal role in preventing pandemics in the future.

public health emergency of international concern (PHEIC)  /  mRNA vaccine  /  viral infectious disease  /  influenza virus  /  Ebola virus  /  poliovirus  /  Zika virus  /  SARS-CoV-2  /  mpox virus