BA.5 more damaging to lungs than earlier subvariants: study

The University of New South Wales study was published on Sunday and cited by Chulalongkorn University (CU) medical lecturer Thira Woratanarat in a Facebook post on Monday.

Thira explained the study showed that BA.5 has a different mechanism for entering human cells from BA.1 and BA.1 subvariants.

Like the Delta strain, BA.5 enters cells via the TMPRSS2 pathway and is more likely to infect the lower lung.

This is reflected by the increased rate of Covid-19 hospitalisation in countries where BA.5 is spreading, said the study.

Titled “SARS-CoV-2 Omicron BA.5: Evolving tropism and evasion of potent humoral responses and resistance to clinical immunotherapeutics relative to viral variants of concern”, the study was published on the medRxiv pre-print server and has not yet been peer-reviewed.

Citing its findings, Thira warned that Covid-19 was still a more serious disease than flu and advised people not to let their guard down against the virus. He said that while vaccines gave some protection, they do not prevent severe symptoms or death in all cases. Moreover, the health risks of long Covid are well-documented, he added.

He said it was still important to take daily precautions such as mask-wearing so people’s lives and livelihoods were not disrupted by catching Covid.