PETALING JAYA (THE STAR/ASIA NEWS NETWORK) - With the number of severe Covid-19 cases among vaccinated people increasing in Malaysia, Health Minister Khairy Jamaluddin has called on all to take booster shots.

He said the effectiveness of vaccines will start to wane after a few months, with the Sinovac vaccine being the quickest to lose its effectiveness.

"While Sinovac is effective, there is evidence its effectiveness wanes sooner. That's why we want you to take whatever booster is on offer," Mr Khairy tweeted on Saturday (Nov 20).

He explained that the faster waning period is the reason why the interval for Sinovac booster shots is three months, compared with six months for Pfizer and AstraZeneca.

In his tweet, Mr Khairy shared a graph showing data for Covid-19 admissions in Hospital Sungai Buloh in the state of Selangor.

It revealed that most of Category 4 and 5 patients are Sinovac recipients.

The last epidemiology week (week 45) saw 165 Sinovac recipients admitted to Hospital Sungai Buloh as Category 4 and 5 patients.

Both categories refer to seriously ill patients in intensive care units (ICUs). Patients under Category 4 require oxygen assistance while those under Category 5 need to be ventilated.

In comparison, 24 were Pfizer recipients while seven had taken the AstraZeneca vaccine.

Mr Khairy's warning comes as Malaysia recorded 4,854 new Covid-19 cases, the Health Ministry said on Sunday.

In a Twitter post, Health ministry director-general Dr Noor Hisham Abdullah said cumulatively, the country had recorded 2,586,601 Covid-19 cases since the pandemic began.

Earlier, the Health Ministry had said through its CovidNow portal that a total of 41 new Covid-19 fatalities were recorded on Saturday, bringing the cumulative death toll to 29,978.

Of the number, six deaths were classified as "brought-in-dead".

As at Sunday, 76.5 per cent of the country's total population had been fully vaccinated and 78.6 per cent had received at least one dose of a vaccine.

Malaysia started administering booster shots in October, with priority for the elderly, the immunocompromised as well as health and security front-liners.

To date, more than a million booster shots have been administered nationwide.