Coronavirus disease 2019 caused by SARS-CoV-2. Multiple vaccine platforms were developed at unprecedented speed, with mRNA vaccines representing a breakthrough in vaccine technology.
COVID-19 is a respiratory illness caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). First identified in Wuhan, China in December 2019, it quickly spread globally and was declared a pandemic by WHO on March 11, 2020 (WHO, 2020).
Symptoms range from mild (fever, cough, fatigue) to severe (pneumonia, acute respiratory distress syndrome, multi-organ failure). Older adults and those with underlying health conditions are at higher risk for severe illness. As of 2024, COVID-19 continues to circulate as an endemic respiratory virus.
Pfizer-BioNTech (Comirnaty) and Moderna (Spikevax). Deliver mRNA instructions for cells to produce spike protein, triggering immune response. Novel platform, 95% efficacy initially.
Johnson & Johnson's Janssen and AstraZeneca. Use harmless virus to deliver spike protein gene. Single dose option, 66-72% efficacy.
Novavax. Contain purified spike proteins with adjuvant. Traditional technology, ~90% efficacy. Storage at refrigerator temperatures.
Sinovac (CoronaVac), Sinopharm. Whole virus inactivated with adjuvant. Widely used globally, efficacy varies by study.