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Researchers say it’s still possible that the world could eradicate COVID-19. Goroden Koff/Getty Images
  • A group of researchers estimate that eradicating COVID-19 is possible, although it would face many challenges.
  • Eradication means reducing global cases to zero and keeping them there until intervention measures — such as vaccines — are no longer needed.
  • While there are several effective COVID-19 vaccines, it’s uncertain how long the protection gained from these will last.

Many experts caution that, even after we roll out COVID-19 vaccines to much of the world’s population, the coronavirus that causes this disease — SARS-CoV-2 — will likely be with us for the foreseeable future.

But a group of New Zealand researchers say we shouldn’t rule out the “possibility of eradicating” COVID-19 from the world.

While this seems like a tall order — especially with the United States once again approaching 200,000 coronavirus cases a day — the researchers estimate that it would be slightly easier than eradicating polio.

However, they estimate that eradicating COVID-19 would be much harder than doing the same for smallpox.

“While our analysis is a preliminary effort with various subjective components, it does seem to put COVID-19 eradicability into the realms of being possible, especially in terms of technical feasibility,” they wrote in BMJ Global Health.

The researchers are not talking about the elimination of COVID-19 — in which a country or region gets case rates to zero, and reacts quickly to squash the occasional outbreak after that.

Eradication means reducing global cases to zero and keeping them there until intervention measures — such as vaccines — are no longer needed.

The global health community has achieved this with smallpox, which the World Health Organization declared eradicated in 1980.

It is attempting to do the same for polio and measles.

The New Zealand researchers’ assessment of the “eradicability” of COVID-19 is based on seven major factors.

One of these is the availability of a highly effective and safe vaccine, particularly one that is cheap and stable.

The smallpox vaccine was a “great success” in the eradication of smallpox, the researchers wrote.

They add that while there are several effective COVID-19 vaccines, it’s uncertain how long the protection gained from these will last.

But they say the mRNA vaccines will likely be improved further, with the potential for the development of intranasal COVID-19 vaccines.

Some scientists think intranasal vaccines may help block transmission of the coronavirus, but more research is needed. No vaccine of this type is currently approved.

Another factor the researchers looked at is whether lifelong immunity occurs after recovering from infection.

People who had smallpox are immune from the virus for the rest of their life. People who had polio are “probably” immune, the authors wrote.

With COVID-19, the duration of the immunity that occurs after natural infection is unknown, although estimates range from months to years.

The researchers also considered whether people can be long-term carriers of the virus, if the disease state is easily recognized, and if there’s an easy way to diagnose infection.

There’s no evidence that people can be long-term carriers of the coronavirus, poliovirus, or smallpox virus.

As for diagnosing COVID-19, this usually requires laboratory testing — or a reliable on-the-go test kit — because certain symptoms are similar to other respiratory illnesses and some people don’t have any symptoms.

In addition, the researchers looked at whether there is an animal reservoir of the virus and whether the virus’ genetic material is stable.

The viruses that cause smallpox and polio don’t occur in non-human animals, so if you can vaccinate all people, you can eliminate the disease.

The coronavirus, though, is known to infect other animals. This could allow the virus to re-emerge to infect people. More research on this possibility is needed.

However, the novel coronavirus has shown that it is capable of generating new variants through mutations. These mutations are more likely to occur when the virus is spreading rapidly, as it is in many parts of the United States right now.

Based on these factors, the researchers put the eradicability of COVID-19 as similar to polio, but much harder than smallpox.

Given the current state of the pandemic — with many countries struggling to vaccinate their high-risk citizens even as wealthy countries roll out booster doses — some experts doubt that SARS-CoV-2 will be gone any time soon.

“Eradication of SARS-CoV-2, like the world did with smallpox, is not a realistic goal for the world at this time,” said Dr. Tom Kenyon, chief health officer at Project HOPE and former director of global health at the Centers for Disease Control and Prevention.

“But that could change as coverage with vaccination improves,” he added.

Dr. Jon Andrus, an adjunct professor of global health at George Washington University, was “pleasantly surprised” that the authors of the BMJ Global Health commentary raised the issue of COVID-19 eradication.

However, “there are enormous challenges,” he said, pointing out that the eradication of polio is over 20 years past its original deadline.

Before even considering eradication of COVID-19 as a goal, certain resources would need to be in place.

“You really need the political commitment and funding upfront — and in this case, it’s not only global, but also regional and national,” said Andrus, who has worked on eradication and elimination programs for polio, measles, and rubella.

A more doable short-term goal might be vaccinating high-risk people in all countries first and then expanding vaccine access to other segments of the population.

“The biggest challenges that remain include achieving high [global] vaccine coverage,” said Kenyon, “and responding to new variants that could bypass our immune response to COVID-19.”

There are other challenges, he said, such as the high costs of eradication or control programs, and the need to move from “vaccine nationalism” to strong cooperation among countries.

In addition, more funding is needed on possible animal reservoirs of the coronavirus, he said.

One only has to look as far as the United States to see how challenging it would be to eradicate COVID-19 globally.

Andrus says sometimes several countries in a region are able to work closely together on a common public health goal, as he has seen with measles elimination in Southeast Asia.

But the United States struggles to find that level of cooperation even within states.

“In certain states — Tennessee, Texas — you may be sitting in one county with a policy that would support physical distancing,” he said, “but you may be right next to another county or town where it’s completely opposite.”

“That’s why it comes back to political commitment again — in all forms and at all levels. And we don’t have that [in the United States].”

The challenges faced by other eradication programs also provides insight into how difficult it might be with COVID-19.

Measles eradication has suffered setbacks in recent years. Andrus says we’re also likely to see large measles outbreaks due to disruptions of measles vaccination programs during the pandemic.

But governments, public health agencies, and others have laid much groundwork to achieve the goal of measles eradication, such as building public health infrastructure and strengthening cooperation among countries.

Many of these resources and international commitments could be extended toward eradicating COVID-19 or toward reaching other public health goals.

“Eradication is a way of reaching everyone,” said Andrus. “By its very nature, eradication addresses equity.”