Coronaviruses are a type of virus that can infect people and cause respiratory illnesses. Several crown-like spikes on the surface of the virus give it the name “corona”. Coronaviruses that cause illness in humans include SARS, Middle East Respiratory Syndrome (MERS), and the common cold. The host’s immune system can help fight the disease. Mammalian hosts have an innate, usually inflammatory response to infections, followed by an adaptive response. The branch of medicine that deals with infections is called infectious diseases. COVID-19 is still a mystery to scientists. What is known is that people infected with COVID-19 can spread the virus to others before they develop symptoms (when they are still “asymptomatic”). If you do develop symptoms, the CDC says you are no longer contagious 10 days after the onset of symptoms.

COVID-19 has claimed the lives of about 18 million people. Researchers are working around the clock to better understand, treat, and ultimately eradicate COVID-19 and the disease that goes with it. WHO and its partners are developing vaccines against COVID-19 as quickly as possible, while adhering to the highest safety requirements. Vaccines go through several stages of research and testing – clinical trials typically have three phases, the last of which is aimed at testing the product’s ability to protect against disease, known as efficacy. Each phase assesses the level of risk. Vaccines have previously been developed through a sequence of steps that can take years to complete. Given the urgent need for COVID-19 vaccines, huge financial investments and scientific collaborations are now reshaping vaccine development.