The Lancet has published a review by 9 researchers and doctors that compares the impact of several previous epidemics and pandemics of coronavirus and influenzas.
The report compares transmissibility, hospitalization, and mortality rates for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, the virus that causes COVID-19) with those of other epidemic coronaviruses, such as severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV), and pandemic influenza viruses.
The basic infection rate, or reproductive rate, for SARS-CoV-2 is the highest of those epidemics/pandemics in the comparison.
SARS-CoV-2 causes mild or asymptomatic disease in most cases; however, severe to critical illness occurs in a small proportion of infected individuals, with the highest rate seen in people older than 70 years. The World Health Organization designated SARS-CoV-2 as a pandemic on March 11, 2020.
The case fatality rate is probably around 1% after adjusting for asymptomatic and mild illness.
So far, the U.S. has had at least 2,852,807 cases of COVID-19 and 129,718 reported deaths.
The Lancet summary is here.
The full Lancet journal article is here.
The chart below may be found in the article by clicking here.
| SARS-CoV-2 | SARS-CoV | Pandemic influenza 1918 | Pandemic influenza 2009 | Interpretation | |
|---|---|---|---|---|---|
| Transmissibility, R 0 | 2·5 | 2·4 | 2·0 | 1·7 | SARS-CoV-2 has the highest average R 0
|
| Incubation period, days | 4–12 | 2–7 | Unknown | 2 | Longer incubation period; SARS-CoV epidemics form slower
|
| Interval between symptom onset and maximum infectivity, days | 0 | 5–7 | 2 | 2 | SARS-CoV-2 is harder to contain than SARS-CoV
|
| Proportion with mild illness | High | Low | High | High | Facilitates undetected transmission
|
| Proportion of patients requiring hospitalisation | Few (20%) | Most (>70%) | Few | Few | Concern about capacity in the health sector
|
| Proportion of patients requiring intensive care | 1/16 000 | Most (40%) | Unknown | 1/104 000 | Concern about capacity in the health sector
|
| Proportion of deaths in people younger than 65 years out of all deaths | 0·6–2·8% | Unknown | 95% | 80% | SARS-CoV-2 might cause as many deaths as the 1918 influenza pandemic, but fewer years of life lost and disability-adjusted life-years, as deaths are in the older population with underlying health conditions
|
| Risk factors for severe illness | Age, comorbidity | Age, comorbidity | Age (<60 years) | Age (<60 years) | ..
|