Data on Measles Cases by Residency Status and Sufficiency of Local Herd Immunity

Mr Yip Hon Weng asked the Coordinating Minister for Social Policies and Minister for Health regarding the recent local measles cases (a) what is the breakdown by residency status and breakthrough infections over the past five year; (b) what is the assessment of undetected community transmission and the risk to Singapore's measles elimination status; and (c) whether current herd immunity is sufficient to protect infants who are ineligible for vaccination.

Mr Ong Ye Kung: Between 1 January 2021 and 31 December 2025, 50 laboratory-confirmed measles cases were notified. Three were tourists, while the remainder were living in Singapore. Six cases were breakthrough infections in vaccinated individuals.

The measles vaccination coverage for resident children at two years of age has been about 93% for Dose 2, and 97% by seven years old. In addition, seroprevalence survey data showed that 99% of adult residents in Singapore have immunity against measles. This is above the measles herd immunity threshold of 95% to prevent population-wide spread and protect those who are unable to receive the vaccination, such as infants under 12 months.

Singapore remains vulnerable to imported cases and small clusters due to pockets of unvaccinated individuals and high travel volumes from measles outbreak areas. There is currently no evidence of sustained community transmission of measles. Our high vaccination coverage, surveillance and prompt public health response help safeguard against the re-establishment of endemic measles transmission.