Omicron Variant: How Worried Should We Be About It?

Research has started to emerge on the latest variant of COVID. How concerned should we be about it, and what makes it different from previous variants?

- By Dr Jeremy Rossman. Photographs Getty Images

Since we first heard about Omicron, the variant has been found in many countries around the world where it is driving the most dramatic spike in COVID-19 cases we have yet seen. In the UK, there were over 30,000 new cases a day in the one-week period from 14 December. On 22 December, cases were nearly double the previous peak seen in January 2021, and Omicron was the dominant variant. Similar trends have also been seen in many other countries after the arrival of Omicron.

The four biggest questions surrounding Omicron are: is it more transmissible, is it more immune evading, does it cause different disease and do we need to do anything different to stop it. We do not have definitive answers to most of these questions, as we are still learning about the variant; however, several studies have recently been published as non-peer-reviewed pre-prints that may help to provide some answers.

The rapid spread of Omicron and the associated spike in COVID-19 cases in many countries suggests that the variant may be more transmissible. This concept is supported by pre-prints that show that Omicron is more infectious and has a shorter incubation period (the time between infection and the start of being contagious) than the Delta variant. However, the rapid rise in Omicron cases may also be due to its ability to evade the protection of vaccine- or infectioninduced immunity.