KUALA LUMPUR (THE STAR/ASIA NEWS NETWORK) - Malaysia's Health Minister Khairy Jamaluddin has advised the public to keep their face masks on and avoid crowded places as the Covid-19 infectivity rate rises.

In a tweet on Saturday (Nov 13), he said the country's Rt rate - the reproduction number that shows how quickly the virus multiplies - is now at 1.04.

"Senior citizens, especially, should get their booster jabs when it's available to them. Practise #TRIIS," he posted.

TRIIS is the acronym for test, report, isolate, inform and seek.

Earlier, the Health Ministry advised the public to not hesitate to take Comirnaty vaccine booster shots to protect themselves, regardless of the vaccine they were administered before this.

With the rising infectivity rate (R0) in the country, the Health Ministry has warned that the public must do their part in protecting themselves and the community.

Health director-general Dr Noor Hisham Abdullah had said that through studies, the heterologous (or mixing) approach has been shown to be effective in offering protection.

It was understood that many recipients who were fully vaccinated using CoronaVac by Sinovac were hesitant to receive the booster shot as it was not the same type of vaccine. Comirnaty is manufactured by Pfizer-BioNTech.

The RO (R-naught) in Malaysia rose to 1.0 on Nov 11, five weeks after interstate travel was allowed.

If the R value is 1 for example, it means that on average, 10 infected persons will spread Covid-19 to 10 others. An R value higher than 1 means that the number of cases will increase.

If the R value falls below 1, the disease will eventually stop spreading as there will not be enough new infected persons to sustain the outbreak.

The last time the country's R value was above 1 was on Aug 31 this year. The country's infectivity rate has been on a downward trend since late July, but it has been inching up since Oct 20.