COVID's new Omicron sub-lineages can dodge immunity from past infection: Study
Two new sublineages of the Omicron coronavirus variant can dodge antibodies from earlier infection well enough to trigger a new wave, but are far less able to thrive in the blood of people vaccinated against COVID-19, South African scientists have found.
The scientists from multiple institutions were examining Omicron's BA.4 and BA.5 sublineages - which the World Health Organization last month added to its monitoring list. They took blood samples from 39 participants previously infected by Omicron when it first showed up at the end of last year.
Fifteen were vaccinated - eight with Pfizer's shot; seven with J&J's -- while the other 24 were not.
"The vaccinated group showed about a 5-fold higher neutralization capacity ... and should be better protected," said the study, a pre-print of which was released over the weekend.
In the unvaccinated samples, there was an almost eightfold decrease in antibody production when exposed to BA.4 and BA.5, compared with the original BA.1 Omicron lineage. Blood from the vaccinated people showed a threefold decrease.
South Africa may be entering a fifth COVID wave earlier than expected, officials and scientists said on Friday, blaming a sustained rise in infections that seems to be driven by the BA.4 and BA.5 Omicron sub-variants.
Only about 30 per cent of South Africa's population of 60 million is fully vaccinated.
"Based on neutralization escape, BA.4 and BA.5 have potential to result in a new infection wave," the study said.
(Editing by Frances Kerry)
CTVNews.ca Top Stories

'No concessions' St-Onge says in $100M a year news deal with Google
The Canadian government has reached a deal with Google over the Online News Act that will see the tech giant pay $100 million annually to publishers, and continue to allow access to Canadian news content on its platform. This comes after Google had threatened to block news on its platform when the contentious new rules come into effect next month.
Here is what Canada's drug shortage situation looks like right now
Compared to the peak pandemic years of 2020 and 2021, Canada experienced an uptick in prescription drug shortages in 2022 that Health Canada says has continued throughout 2023.
opinion Don Martin: With Trudeau resignation fever rising, a Conservative nightmare appears
With speculation rising that Prime Minister Justin Trudeau will follow his father's footsteps in the snow to a pre-election resignation, political columnist Don Martin focuses on one Liberal cabinet minister who's emerging as leadership material -- and who stands out as a fresh-faced contrast to the often 'angry and abrasive' leader of the Conservatives.
U.S. says alleged murder plotter was directed by India and mentioned B.C. killing
U.S. officials have charged an Indian national in a plot to assassinate a Sikh separatist on American soil – in a case they say is connected to the slaying of Hardeep Singh Nijjar in British Columbia.
Manslaughter charges laid against man accused of trafficking gun to teen who killed Edmonton police officers
A 19-year-old man accused of trafficking a firearm to the 16-year-old boy who killed two Edmonton police officers has been charged with manslaughter.
'We wish we could've reached that kid earlier,' says online educator about boy's suicide after apparent sextortion
The chat may seem innocuous at first. The victims, often young men or boys, start communicating with someone posing as a young girl, typically on the popular social media platforms Instagram and Snapchat. But with sextortion, which occurs when people are blackmailed for money or sexual favours, 'sextorters' convince them to share a sexual photo or video.
opinion Five revelations from best-seller 'Endgame' that are sure to upset the Royal Family
Royal commentator Afua Hagan on five revelations in a new book that's sure to send shockwaves through the Royal Family's ranks.
Provinces are moving away from pap smears, but more infrastructure is needed
Some provinces are moving to HPV tests as the primary mode of cervical cancer screening, and others are close behind, an expert says.
Sask. man accused of sexually assaulting 3 boys arrested at daycare
An Assiniboia, Sask. man stands accused of sexually assaulting three boys under the age of 12 was arrested at a home-based daycare.