Thailand’s Department of Disease Control (DDC) says the NB.1.8.1 Covid-19 variant has become the country’s dominant strain, while officials in Singapore are also dealing with a recent rise in infections.
According to the DDC reported by The Nation, NB.1.8.1 accounted for 50.95% of detected SARS-CoV-2 samples in Thailand. DDC director-general Dr Montien Kanasawat said data from the Department of Medical Sciences’ Public Health Research Institute, covering January 1, 2025 to April 23, 2026, showed that NB.1.8.1 was the main variant circulating in the country. It was followed by JN.1 at 24.97% and XEC at 9.14%.
Thailand has recorded 3,642 cumulative Covid-19 cases and one death so far this year, based on disease surveillance data as of May 23. Most patients were aged 30 to 35, followed by those aged 60 and above, and those aged 20 to 29.
The DDC said reported cases had increased over the past month, but remained below the five-year median, suggesting the current trend is still within a seasonal pattern rather than a serious nationwide outbreak.
Dr Montien said NB.1.8.1 is a descendant of the JN.1 variant and has several additional mutations on the spike protein. These mutations may make the virus easier to transmit and better able to evade immunity. However, he stressed that there is still no evidence that NB.1.8.1 causes more severe illness.
The situation in Singapore has also drawn attention after the Communicable Diseases Agency reported a sharp increase in infections, with cases rising to 12,700 in the week of May 10 to 16. That was up by 4,700 cases from the previous week. Average daily hospitalisations also increased from 56 to 73 over the same period, although intensive care cases remained low at about one patient per day.
Singapore’s health authorities said hospitals remain able to manage the current situation and noted that periodic waves of infections are expected as Covid-19 continues to circulate as an endemic respiratory disease.
The agency said there is currently no evidence that the circulating variants are more transmissible or more severe than previous strains, adding that the rise in cases may be linked to waning population immunity over time.
In Singapore, NB.1.8.1 is also the dominant strain, making up more than half of locally sequenced cases. Officials there said existing vaccines remain effective against it.
Health authorities in both countries have urged people at higher risk, including seniors, medically vulnerable individuals, residents of aged-care facilities and healthcare workers, to keep their vaccinations up to date. The wider public has also been encouraged to continue basic precautions such as good hygiene, avoiding unnecessary contact when unwell, and wearing masks when experiencing symptoms.
Meanwhile in Malaysia, Malaysia’s Ministry of Health (MOH) says Covid-19 cases in the country have fallen by 12.6% this year, with 9,682 fewer infections recorded compared with the same period in 2025 in an official statement released today.
In a statement, the ministry said the overall situation remains stable and under control, despite recent increases in cases reported in neighbouring countries. Based on surveillance data up to Epidemiological Week 19 of 2026, MOH said the decline marks a clear improvement from last year, although a slight week-on-week increase of 0.7% was recorded from Epidemiological Week 18.
The ministry said most infections reported this year involved only mild symptoms and did not require hospital treatment. It also confirmed that no Covid-19-related deaths have been recorded in Malaysia so far in 2026.
MOH added that ongoing genomic sequencing has detected several new Covid-19 subvariants circulating in the community. However, current monitoring shows no sign that these variants could cause severe infection waves similar to those seen in the early phase of the pandemic, echoing similar reassurances given by both Thailand and Singapore’s agencies
To reduce the risk of imported cases, the ministry said it will continue strengthening health screening measures at international entry points together with the Border Control and Protection Agency (AKPS).
MOH also said Covid-19 is now being managed in a similar way to other common respiratory infections such as influenza and the common cold. The public is being advised to continue practising good hygiene, wear masks when symptomatic or in crowded places, and stay up to date with vaccinations, especially among high-risk groups.
The post NB.1.8.1 Becomes Dominant COVID-19 Variant in Thailand and Singapore as Both Report Rise in Infections first appeared on PP Health Malaysia.
