There is often confusion about the terms eradication, elimination and control, and these terms are particularly confusing when applied to COVID.
who.int/bulletin/volum…
who.int/bulletin/volum…
Eradication is the permanent reduction to zero of the worldwide incidence of infection. This was achieved for smallpox - we no longer need smallpox vaccination. This isn't going to happen anytime soon for SARS-CoV-2.
Elimination is the reduction to zero of the incidence of disease or infection in a defined geographical area. This implies that continued intervention measures are required to prevent re-emergence and re-establishment of transmission.
For COVID-19, elimination isn't quite the right term. Even if no infections were reported, it would be hard to ensure there weren't any infections anywhere, and there would be the continued high risk of re-importation. go8.edu.au/research/roadm…
For comparison, measles elimination is the absence of endemic transmission for more than 12 months, with a good surveillance system to detect cases. Complete suppression of COVID for this length of time isn't going to be feasible. who.int/immunization/m…
For Ebola, outbreaks are usually declared over if there has not been a case for two incubation periods (42 days), and the term "elimination" is sometimes used. However, Ebola is a much more visible disease. msf.org/new-ebola-case…
Control is the reduction in the incidence or burden of an infectious disease to an acceptable level. This is usually interpreted as meaning that it is no longer a significant public health threat.
This doesn't quite work either - it's likely that COVID will be a continuing public health threat. The most likely outcome is trying to intensify some control measures (case finding and contact tracing) to balance a relaxation in other public health measures.
We probably need better terms to describe what the aims are - perhaps "complete temporary suppression" and "sustained suppression"?
