He added that he has treated symptomatic patients who tested negative with an antigen rapid test kit at home, but was positive when tested at the clinic.
“We do a proper test and we also assess for the complications of COVID-19. That’s why it’s very important to see your doctor,” he advised.
Dr Cheng said that people who test positive but are asymptomatic or have very mild symptoms can recover at home, according to Ministry of Health (MOH) guidelines.
“If they are unwell, they are advised to see a doctor,” he said.
While studies and data overseas have reported more breakthrough infections due to BA.4 and BA.5, clinics here have not seen a clear trend of this happening in Singapore.
“But do keep in mind that we have not reached the peak of the BA.4 and BA.5 subvariant wave yet,” said Dr Cheng.
Professor Paul Tambyah, deputy director of the Infectious Diseases Translational Research Programme at the NUS Yong Loo Lin School of Medicine, said that the rate of reinfection with BA.4 and BA.5 is still low.
“The problem with BA.4 and BA.5 is that they are more transmissible but not necessarily more virulent. This happens with all pandemic viruses. They become more transmissible and less virulent over time,” said Prof Tambyah.
Associate Professor Natasha Howard from the Saw Swee Hock School of Public Health at NUS said that people who have been fully vaccinated and boosted or recently had COVID-19 can still get infected.
“Unless you can avoid people entirely, and most of us wouldn’t want to, it will be almost impossible to avoid any COVID infection (or reinfection) as we adjust to endemicity,” she said.
“This is why we so strongly recommend being fully vaccinated and getting boosted once you’re eligible. If you are fully vaccinated you are less likely to experience severe disease.”
Dr Zhang, whose Bishan clinic offers vaccinations, has also noticed more people enquiring about and taking booster jabs.
“We do see quite a lot of people asking and walking in for vaccinations, which is quite heartening and which we strongly encourage,” he said.
For those who are concerned about reinfection, they should still get their booster vaccination 90 days following recovery, said the Fullerton Health spokesperson.
Assoc Prof Howard said that most seniors should take an mRNA vaccine as a booster, unless they are medically ineligible, in which case they can take Novavax’s Nuvaxovid.
“While these don’t specifically target BA.4/5 subvariants they still provide good protection against severe infection,” she said.
Booster vaccine candidates in the pipeline, such as Moderna’s bivalent booster candidate (mRNA-1273.214) that showed a good response against BA.4 and BA.5, are not yet approved for use.