In December 2019, Malaysia reported its first polio case in 27 years, detected in Sabah state, leading to outbreak investigation and a targeted immunization campaign to control further spread of the disease.
The case was confirmed as circulating vaccine-derived poliovirus type 1 (cVDPV1) after sequencing of an isolate by the Victorian Infectious Diseases Reference Laboratory (VIDRL), Australia. Subsequently, three more cVDPV1 cases were reported in Sabah state through acute flaccid paralysis (AFP) surveillance. What was once thought to be an eradicated disease in the country had now re-emerged.
During the early part of the outbreak, a team from the Malaysia Epidemic Intelligence Program (EIP) assisted in outbreak investigation, aiming to identify a possible source of the outbreak, as well as any missed cases of AFP. Although the source could not be identified, it was hypothesized that infection may have come from asymptomatic individuals. Findings were communicated to the State Health Department and used to develop an outbreak management plan.
Rapid vaccination response was also carried out in the affected locality, targeting children who had missed their routine vaccination. On December 27, 2019 a state-wide Polio Immunization Campaign using bivalent oral polio vaccine (bOPV) was launched. The campaign, Kempen Imunisasi Polio Sabah (KIPS), initially targeted children under the age of five, but later expanded to all children under 13 years old in Sabah. Two months later, the World Health Organization (WHO) bolstered the immunization campaign by providing 2.5 million doses of monovalent oral polio vaccine type 2 (mOPV2) to the Ministry of Health (MOH) Malaysia, thus ensuring complete protection from the virus.
Although initially off to a good start, the campaign faced a number of challenges amidst the declaration of the COVID-19 pandemic in March 2020. National Movement Control Orders (MCO) resulted in a reduction of activities and the eventual need to adapt to COVID-19 restrictions. Healthcare workers were able to resume the campaign at its initial scale with added protective measures in place, including use of personal protective equipment (PPE), and practicing frequent hand hygiene. Despite these issues, frontline health workers were able to successfully conduct the campaign, achieving more than 90 percent coverage for both bOPV and mOPV2 vaccines. The success of the campaign was made possible through the full commitment of staff and volunteers, as well as innovative and creative strategies.