  When the Covid-19 pandemic enters dangerous new phase, whether and when to
take aggressive public health interventions to slow down the spread of
COVID-19. To develop the artificial intelligence (AI) inspired methods for
real-time forecasting and evaluating intervention strategies to curb the spread
of Covid-19 in the World. A modified auto-encoder for modeling the transmission
dynamics of the epidemics is developed and applied to the surveillance data of
cumulative and new Covid-19 cases and deaths from WHO, as of March 16, 2020.
The average errors of 5-step forecasting were 2.5%. The total peak number of
cumulative cases and new cases, and the maximum number of cumulative cases in
the world with later intervention (comprehensive public health intervention is
implemented 4 weeks later) could reach 75,249,909, 10,086,085, and 255,392,154,
respectively. The case ending time was January 10, 2021. However, the total
peak number of cumulative cases and new cases and the maximum number of
cumulative cases in the world with one week later intervention were reduced to
951,799, 108,853 and 1,530,276, respectively. Duration time of the Covid-19
spread would be reduced from 356 days to 232 days. The case ending time was
September 8, 2020. We observed that delaying intervention for one month caused
the maximum number of cumulative cases to increase 166.89 times, and the number
of deaths increase from 53,560 to 8,938,725. We will face disastrous
consequences if immediate action to intervene is not taken.
