As they spread from person to person, viruses constantly change, or mutate. This is normal and happens all the time. When a virus changes enough to significantly affect how it infects and spreads, we call these new variants. It’s also possible that some variants can make people sicker or cause more serious symptoms. We monitor mutated versions of the COVID-19 virus to better understand their impact and help people stay safe.
Since the start of the pandemic, many different COVID-19 variants have emerged and stayed in circulation. These variants are very similar to the original strain but have a few key differences that affect how they spread and infect people. Viruses change over time through a process called natural selection, which means some of these mutations will stick around while others disappear.
Each time a new variant emerges, the World Health Organization gives it a name using letters from the Greek alphabet. So far, we have seen the alpha, beta, delta and omicron variants. These variations can change how the virus binds to and enters cells, how it evades antibodies (made by the immune system during an infection or by the vaccine), and whether or not current treatments and vaccines work against them.
The omicron variant has several mutations that allow it to evade antibodies and spread more easily. The omicron variant has caused more cases and hospitalizations than other variants and is the most likely to lead to an increase in outbreaks and new infections. This is why it is important to get vaccinated.