The SARS outbreak in in 2002-2003 lasted about 3 months. It was not as infectious as COVID-19 and was snuffed out by agressive disease control measures in a single wave of infection:
Other flu outbreaks tend to occur in multiple waves. The 1918-19 Spanish Flu had three peaks over a year:
The 1968-1969 flu had two peaks over a year, being worst in 1969:
H1N1 flu had two waves which meant it lasted six months:
The MERS virus is similar to the virus that causes Covid-19 and keeps coming back even though disease control suppresses it:
What is the prognosis for the duration of the Covid-19 pandemic? Covid-19 may last between 100 days and a year for a given epidemic in a given country. The biggest danger is that isolation will suppress the disease but it will recur once "lockdowns" etc have ended. In this case Covid-19 could be a serious problem for more than a year. In the long run our best hope is a vaccine but there are seven known coronaviruses, four of them are common colds and the other three are SARS-CoV-2 (causes Covid 19), SARS-CoV (Sars) and MERS-CoV (Mers), we have no successful vaccines for the common cold, SARS or MERS so lets hope we get lucky with Covid-19. Another possibility is that treatments will be found that reduce the severity of the infection.
If there is no cure within a year we might expect governments to progressively expose the population to Covid-19 within the limits of their Health Service's response. Periodic isolation could take as long as a year to expose enough of the population to create herd immunity. However, it is still not clear whether, having caught Covid-19 once, you are guaranteed not to catch it again.
Another, better approach might be to stop Covid-19 through isolation and then insist upon testing for all inbound passengers and imposing quarantine for anyone arriving from infected areas of the world. This would be coupled with aggressive contact tracing plus institutional quarantine away from home for all contacts. This approach has been rejected in Europe and the USA because it means a long term commitment to strict border controls.
Whether or not the global economic recession is a "V" shape with full recovery probably depends on the development of a vaccine or drug therapy or aggressive border control as detailed above.
27/03/2020
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| Spanish Flue Epidemics |
H1N1 flu had two waves which meant it lasted six months:
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| H1N1 Epidemic in UK |
What is the prognosis for the duration of the Covid-19 pandemic? Covid-19 may last between 100 days and a year for a given epidemic in a given country. The biggest danger is that isolation will suppress the disease but it will recur once "lockdowns" etc have ended. In this case Covid-19 could be a serious problem for more than a year. In the long run our best hope is a vaccine but there are seven known coronaviruses, four of them are common colds and the other three are SARS-CoV-2 (causes Covid 19), SARS-CoV (Sars) and MERS-CoV (Mers), we have no successful vaccines for the common cold, SARS or MERS so lets hope we get lucky with Covid-19. Another possibility is that treatments will be found that reduce the severity of the infection.
If there is no cure within a year we might expect governments to progressively expose the population to Covid-19 within the limits of their Health Service's response. Periodic isolation could take as long as a year to expose enough of the population to create herd immunity. However, it is still not clear whether, having caught Covid-19 once, you are guaranteed not to catch it again.
Another, better approach might be to stop Covid-19 through isolation and then insist upon testing for all inbound passengers and imposing quarantine for anyone arriving from infected areas of the world. This would be coupled with aggressive contact tracing plus institutional quarantine away from home for all contacts. This approach has been rejected in Europe and the USA because it means a long term commitment to strict border controls.
Whether or not the global economic recession is a "V" shape with full recovery probably depends on the development of a vaccine or drug therapy or aggressive border control as detailed above.
27/03/2020
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