As the rapidly spreading BA.5 Omicron coronavirus subvariant drives a surge in cases in many countries, health experts are urging people to get booster shots and wear masks.
Scientists are also concerned about the new and highly mutated BA.2.75 Omicron subvariant – dubbed Centaurus – as it gains ground in India, where it was first detected in early June.
Leo Poon, a virologist at the University of Hong Kong, said immunity from vaccinations and previous infections was likely to be waning for many people.
“There is some evidence showing that infection
“We have to monitor whether this BA.2.75 is spreading in other countries or not,” he said. “Meantime, those who have been vaccinated, maybe three doses or a booster, tend to have less chance of a severe clinical outcome so I think the best protection still is to get vaccinated.”
BA.5 has also been found to get around immunity, and has so far been detected in 83 countries. The WHO’s latest epidemiological report said BA.5 accounted for 52 per cent of total sequences filed to global database GISAID.
The strain is now dominant in the United States. In the week to July 2, 53.5 per cent of cases were caused by BA.5, compared with 27.2 per cent for BA.2.12.1 and 16.5 per cent for BA.4 – both also Omicron subvariants.
Ashish Jha, the White House’s Covid-19 response coordinator, on Sunday tweeted that there could be a new wave of cases.
“While vaccines continue to be remarkable at preventing serious illness, over time, six or more months out from the last shot, protection against infection wanes substantially, and that sets up a risk, now that BA.5 is dominant, of creating a new wave of infections,” Jha wrote.
Case numbers in the US remain steady at about 100,000 a day and there has not been a rise in deaths or severe cases requiring intensive care.
Again, it is not clear yet whether BA.5 causes more severe disease. In South Africa, where BA.5 was first reported, the BA.5 wave peaked in May, and both hospitalisations and deaths did not surpass the country’s first Omicron wave in late 2021.
But in Portugal, BA.5 has caused an increase in hospitalisations even though the vaccination and booster rates are high.
Jha said people over 50 who have not had a vaccination this year should get one, and anyone going to a large indoor gathering or visiting someone vulnerable should get tested beforehand.
Poon from HKU also noted that masks were still a good idea, especially in crowded places like on public transport. “Masking seems to be an effective way to reduce transmission,” he said.
This article was first published in Asia One . All contents and images are copyright to their respective owners and sources.
