YOUth should know: 5 things about the XBB variant

The XBB variant has greater ability to evade immunity compared to the other variants.

Fitri Mahad

Probably the only person that likes to hear the koels go ‘uwu’.

Published: 26 October 2022, 12:22 PM

The XBB variant is now the predominant subvariant circulating in the community, according to the Ministry of Health (MOH) in a press release on Oct 15. It accounted for 54 per cent of local cases from Oct 3 to 9.

On Oct 18, 11,553 local cases of COVID-19 were recorded. This is more than double the figure on Oct 17, which saw 5,028 local cases.

According to Minister for Health Ong Ye Kung, the wave of infections driven by the XBB subvariant may peak earlier than mid-November, as previously expected.

To better understand the XBB subvariant, Youthopia spoke to Dr Mark Chen, Senior Consultant, National Public Health and Epidemiology Unit at the National Centre for Infectious Diseases (NCID).

Here are five things youths should know about the XBB variant:

1. What is the XBB variant? Where or when was it first detected?

XBB is a descendent of the Omicron family of COVID-19 viruses. It is likely descended from BA.2 sub-variants which were in circulation before the BA.5 variants that recently caused an increase in cases in Singapore.

Some of the earlier sequences were detected in the Indian subcontinent. However, Dr Chen clarified that where the first cases were detected may reflect how much genetic testing is done in a particular location and does not necessarily mean the XBB variant originated there.

2. How is the XBB variant different from the previous ones?

Some international studies have shown that XBB is better able to evade the immunity caused by vaccines and previous infections – including the BA.1 and the older BA.2 variants, which also belong to the Omicron family.

Its greater ability to evade immunity causes it to outgrow other variants, like the BA.5 variant.

However, there is currently no evidence that XBB causes more severe disease than BA.5 or the other Omicron family variants we experienced, shared Dr Chen.

3. Do the current vaccines work on this variant? Should people be getting their boosters?

The boosters “update” the body’s protection against the virus. 

NCID observed that people who are more recently boosted are less likely to be infected even against newer variants. 

It is strongly recommended that people get their boosters once they are eligible, particularly now that the bivalent vaccine is available.

4. What is the bivalent vaccine and how does it help fend against the newer variants?

Dr Chen explained that because the XBB variant is so new, the degree of protection against it by the current bivalent vaccines is not known yet. However, the bivalent vaccines are designed using both the original virus and one of the Omicron subfamily viruses.

Hence, the bivalent vaccine is likely to give better protection against XBB than the vaccines that were designed using only the original virus.

5. What should youths be encouraged to do, in view that the recent increase in local cases were driven by XBB?

While youths are much less likely to get severe illness should they catch COVID-19, they can still spread the infection to others who may be vulnerable, like elderly household members.

To reduce the chances of catching and passing on the virus, Dr Chen urges those eligible to get their boosters should quickly do so. It is also advised for those with symptoms to not go out unnecessarily.

Those visiting vulnerable individuals like the elderly or going to large gatherings can also perform an Antigen Rapid Test before going.

Youths can also opt to voluntarily wear a mask even in settings where it is not required such as in crowded indoor venues, Dr Chen added.

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