New research by Kiwi scientists suggests wiping COVID-19 out is a possibility - saying if we beat polio, we can beat this virus too.
And we might not even have to wait until most of the world is vaccinated either, according to their paper published in BMJ Global Health on Tuesday.
"Elimination of COVID-19 at the country level has been achieved and sustained for long periods in various parts of the Asia Pacific region, which suggests that global eradication is possible," said lead author Nick Wilson, a public health professor from the University of Otago.
Elimination and eradication are different. Elimination is when a virus no longer spreads in a community, but there can be outbreaks brought in from outside - measles is an example here in New Zealand. Eradication is when the virus is basically extinct in the wild.
Dr Wilson and his team looked at various factors, "including the availability of safe and effective vaccines, the possibility of lifelong immunity, the impact of public health measures, effective infection control messaging by governments, political and public concern about the infection and public acceptance of infection control measures" and ranked COVID-19 against two previously eradicated viruses - smallpox and polio.
They found polio to be the most difficult virus to eradicate of the three, with a score of 1.5 on their scale. SARS-CoV-2 - the virus behind COVID-19 - was only just behind on 1.6, while smallpox scored 2.7.
"COVID-19 eradication seems slightly more feasible than for polio, but much less so than for smallpox," the paper concluded.
Smallpox didn't require widespread vaccination or herd immunity to be wiped out - Dr Wilson saying it was achieved through "ring-vaccination programmes which target the contacts of those infected".
Smallpox was defeated 40 years ago. There have been no cases recorded since the 1970s. Polio is incredibly rare now, with just a few dozen cases a year. The last recorded case in New Zealand was in the early 1960s.
"Unlike smallpox and polio, control of COVID-19 also benefits from the added impact of public health measures, such as border controls, social distancing, contact tracing and mask wearing, which can be very effective if well deployed," added co-author Michael Baker, an epidemiologist at the University of Otago.
While New Zealand's widely praised zero-COVID strategy has had the advantage of no land borders to monitor and a low population, the paper notes elimination has been achieved in a range of different scenarios - including countries with large land borders (China) and high population densities (Hong Kong).
Impediments to eradicating COVID-19 include growing vaccine hesitancy thanks to misinformation and the emergence of new variants.
Another problem could be animals acting as viral reservoirs, unleashing the virus on us again after it was otherwise wiped out. Dr Wilson played that possibility down, saying vaccines for animals were in development and if all else failed, infected herds could be culled.
"Wild animal infections with SARS-CoV-2 appear to be fairly rare to date and when companion animals become infected, they don't appear to reinfect humans."
Dr Baker said going hard against COVID-19 might even help eradicate other viruses, such as measles.
"When all factors are taken into account, it could be that the benefits of eradicating COVID-19 outweigh the costs, even if eradication takes many years and has a significant risk of failure."
