Within 180 days of their first positive test, people who have recovered from Covid-19 and are well will not need to take an antigen rapid test that is required before some events in a pilot scheme that will run from this month to December.

The reason is that they are very likely to be immune to another round of infection, based on current evidence, said the Ministry of Health (MOH) at a media briefing yesterday.

This pre-event testing, which will be piloted at selected functions such as wedding receptions, live performances and sports gatherings, complements existing safe management measures – such as mask-wearing, safe distancing, and group size and capacity limits – and is not meant to replace them.

Participants must test negative before they can gain entry into the event. The test result will be valid for 24 hours.

Antigen rapid tests, which can yield results more quickly, will be used for such testing, although they have a lower accuracy rate compared with PCR (polymerase chain reaction) tests, which are considered definitive tests for confirming Covid-19 cases.

The pilot programme is being done to allow MOH to study the processes involved to conduct such testing, and for more large-scale events to resume eventually.

The ministry said: “At this stage, we are confident that for those who have recovered from an infection and remain well and asymptomatic, we don’t think we need to test them for a period of 180 days.

“But we’re looking very closely at the evidence as well as the various studies we’re doing for recovered people… to determine whether we can safely extend that period beyond 180 days and exempt people further from other tests.”

This period of exemption applies not just to those involved in the pilot scheme, but also to others who need to do PCR tests, like migrant workers who have to undergo rostered routine testing every 14 days.

MOH added that it is looking at data not just from Singapore, but also internationally.

But as the understanding of immunity to Covid-19 is still evolving, the ministry said there is a need to act cautiously and not extend the period of exemption unless it is confident it can do so.

“We’re mindful that there have been reports of recurrent infections (elsewhere)… as the interval lengthens, there’s always a risk that there will be a few people with recurring infections coming in,” it said. “We’ve not seen that in Singapore, but that possibility always exists and, therefore, we’re being careful.”

Lim Min Zhang