The outbreak of a novel coronavirus infection began in December 2019 in Wuhan, Hubei province, China, when clinical cases of pneumonia were reported to local health authorities. Initial investigations linked many of these cases to the Huanan Seafood Wholesale Market, where live animals were also sold. This prompted an intensive epidemiological investigation, and by January 2020, the cause was identified as a new strain of coronavirus later named SARS-CoV-2. This virus was found to cause the disease termed COVID-19, which became the focus of global health attention due to its rapid human-to-human transmission.

As the outbreak gained momentum, Chinese authorities implemented strict measures, including lockdowns and travel restrictions, to control the spread. The World Health Organization (WHO) was notified, and on December 31, 2019, it issued a statement regarding this unusual cluster. The identification of the virus was crucial for developing diagnostics, treatments, and preventive measures. The outbreak led to global concern as countries around the world prepared to respond to a potentially widespread infectious disease.

The international response intensified as COVID-19 spread beyond Wuhan, leading to outbreaks in many countries across different continents. The outbreak's implications were profound, influencing public health policies globally and leading to unprecedented collaborations in vaccine development as a way to combat the virus. Scientists and pharmaceutical companies accelerated research to develop an effective vaccine, reflecting the urgent need for public safety and health preparedness in an increasingly interconnected world.