A new variant identified in southern Africa is causing global panic – but its real impact will be shown by the data scientists are racing to establish

• Prof Devi Sridhar is chair of global public health at the University of Edinburgh
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Omicron, the name of the new Covid-19 variant that is sending worrying signals from southern Africa, sounds like something from Transformers. It has caused panic across the world, among governments, the public and the stock markets. After adding a number of southern African countries to the red list, the UK government has reimposed mandatory masks in England from Tuesday, and will require anyone travelling to the country from abroad to take a PCR test. Omicron is probably the first variant to have scientists worried since Delta became the predominant strain in every country last summer. But how bad it is? What does it mean for future lockdowns – and future deaths?

Scientists are waiting on three pieces of data before they will be able to tell what effect this new variant will have over the next six to 12 months. The first is how infectious Omicron is. Can it outcompete Delta? Earlier this year we saw another worrying variant, Beta, that luckily faded away as a result of a selective advantage in Delta that allowed it to transmit faster between people. Limited data from South Africa shows that Omicron is very infectious, but whether it will become the predominant strain remains to be seen.

Prof Devi Sridhar is chair of global public health at the University of Edinburgh