Advertisement
As I see it | Omicron sub-variants latest challenge for China’s zero-Covid policy
- BA.4 and BA.5 appear to have a greater ability to escape the protections of vaccination and previous Omicron-caused infections
- Scientists say the sub-variants could be more contagious but there is so far no evidence they cause more severe illness
Reading Time:2 minutes
Why you can trust SCMP
9
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.
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 could be more contagious than Omicron, but so far there is no evidence to suggest they cause more severe disease.
But they are spreading quickly. Last week, the US CDC said the two sub-variants accounted for around 13 per cent of the country’s infections as of June 4.
And on Monday, the European Centre for Disease Prevention and Control warned of a potential surge in coming weeks which could result in more deaths and hospitalisations because of the sub-variants.
What are the implications for China?
Advertisement