The Covid-19 pandemic, which subsided at the end of 2020, re-emerged with the Delta variant in India in February 2021 and quickly spread to Asia and various other parts of the world, threatening health and humanity. The Delta variant is highly contagious and has a more virulent impact on human health and mortality than the Alpha and other variants.
In 2021 more than 95% of Covid-19 transmission cases in various countries, including Indonesia, were due to the Delta variant with a viral load 1,260 times higher than the original variant. Furthermore, the incubation period for Delta is also shorter, at about 4 days after exposure, compared to an average of 6-14 days in the original variant.