1918 Influenza A (H1N1) pandemic | AIDS epidemic (cumulative, ongoing since 1981) | COVID pandemic (ongoing) | |
---|---|---|---|
World population | 1.8 billion | 7.8 billion | 7.8 billion |
Number of deaths | 50 million | 40.1 million | 6.9 million |
Percent deaths | 2.5% | 0.5% | 0.9% |
Duration | 2 years | 42 years | 3 years |
Epidemic curve | “W”: young adults and extremes of age | Inverted “U”: young adults | “U”: extremes of age |
Number infected | 500 million | 84 million | 670 million |
Percent infected | 30% | 1.1% | 8.6% |
AIDS = acquired immunodeficiency syndrome