A new highly transmissible variant of COVID-19 has been detected in Australia, raising questions about whether it will lead to a wave of COVID-19 cases over summer. XEC is a "recombinant" COVID-19 variant, which means it's a mix of two previous Omicron subvariants called KS 1.1 and KP 3.3. Dr Griffin says the XEC strain makes up about 5 to …