Do Covid-19 vaccines work against Omicron? 5 things to know

In order to differentiate between a Delta infection and an Omicron infection, the authorities are relying on a specific polymerase chain reaction test.

Cheryl Tan

Cheryl Tan

The Straits Times


When faced with unknowns, we buy insurance, said Mr Ong Ye Kung, which is to push ahead with the existing vaccinations.PHOTO: REUTERS

November 30, 2021

SINGAPORE – Singapore has made “good progress” in living with the Delta variant, but the new Omicron variant, being an “unknown enemy”, is throwing a spanner in the works, said Health Minister Ong Ye Kung on Tuesday (Nov 30).

Speaking at a press conference by the multi-ministry task force tackling Covid-19 here, Mr Ong highlighted five things we would need to know about the Omicron variant.

1. Will Omicron emerge as a new dominant variant?
Singapore would need to find out if the Omicron variant will dominate the other variants, just like how the Delta variant did so previously.

Mr Ong noted that in South Africa, the Delta variant had been on the wane with fairly few cases before the Omicron variant emerged.

Noting that instances of two variants dominating at the same time are rare, he said: “Where in the world have we noticed a clash between the two variants?”

2. What kind of time frame are we looking at for Omicron to become dominant?
Drawing reference from the Delta variant, Mr Ong noted that it took Delta around three to four months to become the predominant variant around the world.

“So if Omicron is very infectious, it may be faster than three to four months,” said Mr Ong. However, he noted that the spread of the variant can also be slowed down due to countries being a lot faster in introducing new border measures.

So far, Britain, European Union member states, Japan, Australia, Israel and South-east Asian countries including Singapore, have all taken swift actions to suspend entry of travellers from affected countries.

“So… even if Omicron establishes itself and causes large epidemics around the world… this period of a couple of months gives us valuable time to understand this variant, find out more about it, and put in place the appropriate countermeasures,” he added.

3. Can antigen rapid tests and other tests detect Omicron at the same level as other variants?
In order to differentiate between a Delta infection and an Omicron infection, the health authorities are relying on a particular type of polymerase chain reaction test that is able to pick up Covid-19 infections of all variants.

Pointing to this particular test supplied by Thermo Fisher, Mr Ong said that its PCR test is able to “go beyond” identifying a person as being infected by Covid-19. It can also indicate if the person is likely infected by the Omicron variant. It does so by looking for a particular difference in the viral gene.

Mr Ong said the Thermo Fisher PCR test will be prioritised for travellers so that differentiated healthcare protocols can be rolled out for those who are infected with Omicron.

Their swab samples will be prioritised for viral genetic sequencing to ascertain early if they are infected with the Omicron variant.

4. How infectious is the Omicron variant and is it more harmful than Delta?
As this is an area that is still unknown, healthcare protocols will be a lot stricter and “quite similar” to the initial protocols that were implemented when Singapore first encountered Covid-19, said Mr Ong.

For one, if an individual is suspected of being infected with Omicron, he will be admitted to the National Centre for Infectious Diseases.

“If confirmed, they will be managed there until we are confident that the person is non-infectious, through repeat testing,” he added. The home recovery programme is not an option for this group.

Dedicated isolation facilities will also be ready should public health considerations justify this, said Mr Ong. Full contact tracing will also be carried out.

5. How well do existing vaccines work against the Omicron variant?
When faced with unknowns, we buy insurance, said Mr Ong, and Singapore will push ahead with vaccinations.

“It is not a case where there are mutations and hence the existing vaccines will not work, because the human body is much more capable than that. Once vaccinated, there is a good chance that existing vaccines will work against Omicron,” he added.

In South Africa, Mr Ong noted that among the Omicron cases with severe symptoms, 65 per cent are unvaccinated and the remaining 35 per cent are partially vaccinated.

While this is very brief early data, it suggests that the vaccines could still be effective, which underscores their importance.

“So please continue to get your vaccinations and booster shots,” he added.

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