THERE is not enough data to support a second Covid-19 booster dose despite the emergence of the recombinant Omicron XE sub-variant, which the World Health Organization said is 10% times more contagious, health experts said.

The Israel experience showed that a fourth vaccine dose had little to no effect.

Pharmaceutical companies will need to come up with new vaccines to combat the new variants, they said.

Universiti Malaya Department of Social and Preventive Medicine Prof Dr Moy Foong Ming said there is not enough data to support the need for a second booster shot.

“Although we know that Omicron XE is 10% more infectious than the current Omicron variant, we are not sure if Omicron XE presents with more severe symptoms or if the vaccines are not effective against it.

“We need more evidence and data showing that a second booster is required or the first booster has sufficiently waned.  

“This needs to be considered through continuous monitoring of data from the West as well as our own country. At this point, a second booster dose may be premature,” she said.

Dr Malina Othman, an epidemiologist from Universiti Putra Malaysia, said there is no need for a fourth dose as the current health measures are sufficient.

“Data are needed to justify whether we require a fourth shot,” she told The Malaysian Insight.

The Omicron XE variant was first discovered in the UK on January 19. It is a mutation of the Omicron BA.1 and BA.2 strains.

While Omicron XE has not been detected in Malaysia, health experts warn that it is a matter of time before it hits our shores, especially now that the borders are open.

Clinical studies in Israel, one of the first countries to administer a fourth dose, showed that the vaccine restores antibodies to levels observed after the third dose but provides only a modest boost in protection against infection.

In the United States, the Centers for Disease Control and Prevention (CDC) have recommended a fourth dose for people who are above 50 and who are immune compromised.

Fourth dose should be a new vaccine

Former deputy health minister, Dr Lee Boon Chye said existing vaccines are not suitable to serve as a fourth dose.

“We need a new vaccine or a better vaccine. I don’t think the existing vaccines are suitable or are proven to be effective for the fourth dose.”

Lee said it is inevitable that people will need repeated shots, just like they do for the common cold, but the vaccine must be effective.

Pfizer and BioNTech are currently working on a new vaccine targeting the Omicron variant which they say affords more protection than the original two-dose vaccine regimen.

Malaysia will also be getting ahead of itself by requiring a fourth dose given that nearly 10 million have not been boosted by a third shot, he said.

“We should focus on that and make sure that everyone has gotten it. The booster is helpful, at least until now it is protective in terms of reducing infections, hospitalisation and deaths.”

Only about 15 million people, or 48.8%, of the adult population have received a third shot.

Vaccine fatigue

Galen Centre for Health and Social Policy CEO Azrul Mohd Khalib said making people take a fourth shot could lead to vaccine fatigue.

“People may be tired, fatigued or just fed up with vaccinatation, but the fact remains that if another jab means increased protection, then that is what we need to do.

“However, I don’t believe in forcing people into getting vaccinated; they should do it voluntarily,” he said.

Public health expert Dr Zainal Ariffin Omar said the government can expect pushback if a fourth shot is introduced.

“They can expect to face higher booster hesitancy and anti-vaccine sentiment.” – April 11, 2022.