COVID-19 is a contagious disease caused by a virus. From 2019 it caused an ongoing worldwide pandemic.

Over 10 million people are likely to have died from COVID so far. Around 10% of the global population may already have been infected.

While many people don’t show any symptoms at all, in severe cases COVID leads to respiratory failure and even death. Those in vulnerable groups - including the elderly and pregnant women - are at higher risk.

COVID is usually spread by breathing air from people who are already infected. Face masks, good ventilation, and social distancing are good ways of staying safe.

Vaccination reduces the risks of serious illness a lot.

What are COVID variants?

The virus which causes COVID keeps changing and evolving. This means that new types of the virus - ‘variants’ - can emerge and spread.

The main variant worldwide is called the ‘Delta’ variant. This spreads more easily than the first variants, and causes worse health problems - including amongst young people.

The Delta variant was first detected in India in late 2020. The original variants emerged in China, and seem likely to be mutant versions of a virus which infects bats. Viruses are constantly evolving, so there are many new variants too, which scientists are monitoring.