As the daily number of Covid-19 cases in Singapore subsides, many are still keeping an eye out for a highly transmissible Omicron sub-variant known as BA.2, which was the driver of the Republic’s earlier Covid-19 wave.
Here’s what we know so far about the sub-variant.
1. What is it?
Viral mutations lead to new variants. Sometimes, these variants can split into sub-lineages. For example, the Delta variant includes 200 subvariants.
Omicron variants are generally composed of three genetically distinct subvariants. BA.1 and B.2 are the most dominant.
These sub-lineages do not exist, and each Omicron branch has its own set unique mutations.
The BA.1 subvariant was the first to break out, while BA.2 took longer for it to become significant.
2. It is how transmissible?
Preliminary studies have shown that BA.2 may be more transmissible than BA.1, despite all Omicron subvariants being highly contagious.
It has been reported that scientists suspect that BA.2’s rapid growth is due to its mutations. There are eight mutations in BA.2’s gene for the spike protein, which is located on the surface virus.
For instance, a Danish pre-print published on Jan 30 about a study of 8,500 households said scientists found that people with BA.2 were substantially more likely to infect others in the same household compared with BA.1.
(Read also “On Home Recovery? Here Are Disinfection Tips And Precautions To Take“)
Pre-prints refer to articles that have not yet been peer reviewed and evaluated by the medical community.
A study published in Hong Kong on March 10 revealed that the virus doubled in duration during a BA.2 infection in a public housing community.
The three buildings in the housing estate were quickly locked down to stop the spread of the disease.
3. Is the BA.2 subvariant likely to lead to more severe diseases?
The Omicron variant is significantly less likely to become seriously ill, hospitalized, or die than the Delta or older variants.
Research has shown that BA.2 is not different from BA.1 on this point.
Many people have acquired immunity through vaccinations and infections with Covid-19 earlier variants.
It was also reported that Omicron is less severe because it is less harmful to the lungs.
This is different from previous versions, which can cause more damage to the lungs and worsening of breathing difficulties.
4. Are vaccines still effective?
BA.2 doesn’t seem to change the current knowledge about Omicron. Omicron is known to cause breakthrough infections in vaccine-vaccinated individuals better than other variants, which is why the case surge reached record levels.
Vaccines provide significant protection against infection, particularly severe diseases.
Booster shots increase protection.
(Read also “Pfizer Or Moderna: Which Booster Shot Is More Effective?“)
Researchers discovered that booster shots could be effective against BA.1 or BA.2 infections in a study published in a preprint of Qatar, March 13. The boosters were only 90 percent effective against hospitalisation.
According to the World Health Organisation’s website, there has been no evidence of reinfection with BA.2 in cases of infection with BA.1. Initial data suggests that BA.1 infection provides strong protection against reinfection by BA.2.
This article was published in The Straits Times for the first time.
Source: Her World