CHICAGO, Nov. 3 (Reuters) – As the devastating rise of the Delta variant slows in many regions of the world, scientists are mapping when and where COVID-19 will transition to an endemic disease in 2022 and beyond, according to Reuters interviews with more than a dozen leading disease experts.
They expect the first countries to emerge from the pandemic will have had a combination of high vaccination rates and natural immunity in people infected with the coronavirus, such as the United States, the UK, Portugal and India. But they warn that SARS-CoV-2 remains an unpredictable virus that mutates as it spreads through unvaccinated populations.
No one would completely rule out what some call a “doomsday scenario” in which the virus mutates to evade hard-won immunity. Still, they expressed increasing confidence that many countries will have put the worst of the pandemic behind them in the coming year.
“We believe that between now and the end of 2022, this is the point where we can get this virus under control… where we can significantly reduce serious illness and death,” said Maria Van Kerkhove, epidemiologist who leads the World Health Organization (WHO). COVID-19 response, told Reuters.
The agency’s opinion is based on work with disease experts mapping the likely course of the pandemic over the next 18 months. The WHO aims to have 70% of the world’s population vaccinated by the end of 2022.
“If we achieve that goal, we will be in a very, very different situation epidemiologically,” said Van Kerkhove.
Meanwhile, she is concerned about countries that are lifting COVID precautions prematurely. “It’s great for me to see, you know, people on the street, like it’s all over.”
According to the October 26 WHO report, cases and deaths from COVID-19 have decreased in almost all regions of the world since August.
Europe was an exception, with Delta wreaking further havoc in low-vaccination countries like Russia and Romania, as well as places where mask-wearing requirements have been lifted. The variant has also contributed to rising infections in countries like Singapore and China, which have high vaccination rates but little natural immunity due to much stricter lockdown measures.
“The transition will be different in every place because it will be driven by the amount of immunity in the population against natural infections and of course the distribution of vaccines, which is variable… from province to province to country to country,” said Marc Lipsitch, an epidemiologist at the Harvard T.H. Chan School of Public Health.
Several experts said they expect the US Delta wave to end this month and be the last major COVID-19 wave.
“We’re moving from the pandemic phase to the more endemic phase of this virus, where this virus is just becoming a persistent threat here in the United States,” said Scott Gottlieb, former Commissioner of the Food and Drug Administration.
Chris Murray, a leading disease predictor at the University of Washington, also sees the rise in the US delta ending in November.
“We are going into a very modest winter increase” in cases of COVID-19, he said. “If there are no major new variants, then in April, COVID will really start to subside.”
Even where cases are rising as countries drop pandemic restrictions, such as in the UK, vaccines seem to keep people out of the hospital.
Epidemiologist Neil Ferguson of Imperial College London said that for the UK, “most of the pandemic as an emergency is behind us”.
‘A GRADUAL EVOLUTION’
COVID-19 is still expected to remain a leading cause of morbidity and death in the coming years, as are other endemic diseases such as malaria.
“Endemic does not mean benign,” said Van Kerkhove.
Some experts say the virus will eventually behave more like measles, still causing outbreaks in populations where vaccination rates are low.
Others see COVID-19 becoming more of a seasonal respiratory illness, like the flu. Or the virus could become less deadly, affecting mostly children, but that could take decades, some said.
Ferguson of Imperial College expects above-average deaths in the UK from respiratory illness caused by COVID-19 over the next two to five years, but said it is unlikely to overwhelm health systems or require a reintroduction of social distancing.
“It’s going to be a gradual evolution,” Ferguson said. “We’re going to approach this as a more persistent virus.”
Trevor Bedford, a computational virologist at Fred Hutchinson Cancer Center who tracks the evolution of SARS-CoV-2, sees a milder winter wave in the United States, followed by a transition to endemic disease in 2022-2023. He predicts 50,000 to 100,000 U.S. COVID-19 deaths per year, on top of the estimated 30,000 annual deaths from flu.
The virus is likely to continue to mutate, requiring annual booster shots tailored to the latest circulating variants, Bedford said.
If a seasonal COVID scenario plays out, where the virus circulates along with the flu, both Gottlieb and Murray expect it to have a significant impact on healthcare.
“It’s going to be a problem for hospital planners, like how do you deal with the COVID and flu peaks in the winter,” Murray said. “But the era of… massive public intervention in people’s lives through mandates, that part I think will be done after this winter wave.”
Richard Hatchett, chief executive of the Coalition for Epidemic Preparedness Innovations, said that with some countries well protected by vaccines while others have virtually none, the world remains vulnerable.
“What keeps me up at night about COVID is the concern that a variant might emerge that evades our vaccines and evades immunity from previous infection,” Hatchett said. “That would be like a new COVID pandemic popping up, even if we’re still with the old one.”
Report by Julie Steenhuysen; Editing by Michele Gershberg and Bill Berkrot
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