COVID-19 pandemic: Impact of lockdown, contact and non-contact transmissions on infection dynamics

Shovonlal Roy

With the infection suppression measures, it would be essential to check not only the primary peak, but also the secondary peak and the delay in peak occurrence under different transmission rates (Fig. 4) . Although longer lockdown reduces the primary peak, the scale of the reduction does not change beyond a certain point of time (first and second window, Fig. 4 ). Non-contact transmission plays a key role here, and if this transmission rate is proactively reduced through disinfection measures, the impact of longer lockdown will be realised on the number of new cases. Under a hypothetical scenario, with a 50% reduction in contact transmission and 10% reduction in non-contact transmission, any impact on the primary peak and its occurrence may cease after 30 days of lockdown. However, under the same set up, if both transmissions reduce by 75%, the impact on primary peak and its occurrence can persist 90 days and beyond, which will bring down the primary infection cases (first and second window, Fig. 4) .