The COVID-19 pandemic, which began in late 2019 in Wuhan, China, represents one of the most transformative global health crises in modern history. Initial outbreaks were linked to a seafood market, though debates about its precise origins continue. The virus, identified as SARS-CoV-2, spread rapidly across borders, prompting the World Health Organization (WHO) to declare a pandemic in March 2020. Over 7 million deaths have been officially reported, though experts estimate the actual toll exceeds 20 million. Older adults and those with underlying conditions remain the most vulnerable. Vaccination campaigns, initiated within a year of the virus’s discovery, have significantly mitigated severe outcomes. However, inequitable vaccine distribution highlighted disparities between affluent and developing nations, raising concerns about global preparedness for future pandemics.

The virus’s ability to change its genes has made it necessary to stay alert. Variants like Delta and Omicron appeared with different traits, affecting how easily they spread and how severe the illness is. Omicron, first found in November 2021, spread quickly but usually caused less severe illness than Delta, likely because of increasing immunity from vaccines and past infections. Even with progress, long COVID—a condition with ongoing symptoms like tiredness and memory problems—remains a serious issue, affecting millions around the world. Research on treatments and new vaccines, including nasal versions to stop infections, is ongoing. Scientists stress the need to keep track of changing variants and fix gaps in healthcare to strengthen the global response to new diseases.