The Ministry of Health in Indonesia is currently conducting an epidemiological investigation into the Omicron XBB.1.16 or Arcturus subvariant to determine whether it is the reason behind the recent surge in COVID-19 cases in the country. The investigation has been triggered by the discovery of two Arcturus cases in Jakarta residents in March 2023. The Ministry is intensifying genomic surveillance to identify the cause of the recent increase in daily cases, which have risen from an average of 200-300 to around 900 in the last two weeks. Although Arcturus and the BA.4 variant share the same transmission pattern as in India, the current death rate is relatively low. The Arcturus subvariant is suspected of being able to reduce protection by antibodies obtained naturally through infection or vaccination. Although the average treatment period of patients is five to six days, the two Arcturus patients in Jakarta have fully recovered, indicating that protection from immunization is still sufficient to fight this variant. The Ministry of Health is urging individuals to obtain their second booster vaccine dose and get tested if they experience COVID-19 symptoms. Isolation or health protocols remain key to fighting new variants.