Part 3/13:
Initially, Singapore's health officials believed that COVID-19 might behave similarly to SARS—where transmission was primarily symptomatic. However, as data unfolded, it became clear that SARS-CoV-2 did not conform to this pattern. The virus was capable of asymptomatic transmission, with individuals carrying high viral loads even without symptoms. This revelation in late February and March prompted major adjustments to Singapore's containment approach, emphasizing universal mask-wearing and more aggressive testing.