Omicron sub-variants latest challenge for China's zero-Covid policy | South China Morning Post

Two sub-variants of Omicron - the highly transmissible version of the virus behind Covid-19 - are heading for dominance, with regulators and scientists monitoring their potential to spark another wave of infections. The emergence of BA.4 and BA.5 has put pressure on Western countries planning to treat Covid-19 as endemic, because they appear to have a greater ability to escape the twin protections of vaccination and previous Omicron infection. Will the coronavirus continue to evolve after Omicron? That means people previously infected with Omicron may not be protected against the sub-variants from the same lineage. Scientists say the two sub-variants…