Endless articles come out with headlines like "herd immunity is out of reach" even though we have contained even more infectious diseases through vaccination.
From the CDC:
Data are for the U.S.
- Percent of children vaccinated by age 24 months against measles, mumps, rubella: 90.8% (2015)
- Percent of adolescents aged 13-17 years vaccinated against measles, mumps, rubella (2 doses or more): 91.9% (2018)
Source:Health, United States, 2019, table 31 [PDF-9.8 MB] and table 32 [PDF – 9.8 MB]
An R0 of 2.5 – the absolute maximum the WHO considers likely – would give COVID-19 an infection rate on par with the influenza pandemic of 1918 (2 to 3), at the high end of estimates for the 2014 Ebola outbreak (1.5 to 2.5) and at the low end of estimates for SARS (2 to 5).
Several common infectious diseases have much higher R0s, including measles (12 to 18), rubella (6 to 7) and mumps (4 to 7). Lower R0s were calculated for two recent outbreaks that caused pandemic fears – H1N1 influenza in 2009 (1.46 to 1.48) and MERS (0.3 to 0.8).