KUALA LUMPUR - A total of 204 workers at a vaccination centre in Selangor have tested positive for Covid-19, coordinating minister for immunisation Khairy Jamaluddin said on Tuesday (July 13).

The positive cases were detected following a mass screening exercise on all 453 workers and volunteers at the Ideal Convention Centre (IDCC) in Shah Alam on July 10, after two volunteers were infected, he told a news conference.

He said that all those who tested positive have been isolated and a new team of workers will man the vaccination centre after it is closed for sanitisation for one day on Tuesday.

"Because of the high number of cases in Klang Valley, it is difficult for us to determine whether the infections took place at IDCC or elsewhere," said Mr Khairy.

"The good news is that those who are positive have a low virus load. This may be because most of them are vaccinated," he said, adding that the affected workers did not exhibit severe symptoms.

Some 88 per cent of the workers have been vaccinated, while 12 per cent have yet to receive their inoculations.

The Klang Valley is currently the worst-hit area in Malaysia's Covid-19 crisis. On Monday, Selangor recorded 4,308 cases and Kuala Lumpur, 609 - out of a total of 8,574 nationwide.

Those who were at the convention centre between July 9 and July 12 are advised to get tested for Covid-19 if they experience any symptoms within 10 days.

This is the first time a vaccination centre in Malaysia has had to be closed because of a Covid-19 outbreak.

English daily The Star reported that those scheduled to be vaccinated at the IDCC have received or are receiving notifications of the closure.

Ms Shahira Hussin, who was supposed to get her vaccination at the IDCC on Tuesday, found out that her appointment was cancelled after she received an SMS to check her MySejahtera contact tracing app.

"My husband found out on Twitter this morning that the IDCC was going to be closed for sanitisation. At the time, I checked MySejahtera and there were no updates yet.

"But at around 8am, I received an SMS to check MySejahtera and a new slot had been given for July 19," the 32-year-old said when contacted.