Is COVID Herd Immunity A Dwindling Potential?

641

  • The Omicron variant, which is spreading far faster than previous versions of the coronavirus, is not likely to help countries achieve so-called herd immunity against COVID-19, in which enough people become immune to the virus that it can no longer spread, leading disease experts to say.
  • That is not to say that prior immunity offers no benefit.
  • Still, the hope for herd immunity as a ticket back to normal life is hard to shake.

According to disease specialists, the Omicron form of the coronavirus, which is spreading far quicker than previous versions of the virus, is unlikely to help countries establish so-called herd immunity against COVID-19, in which enough individuals become immune to the virus that it can no longer spread as reported by Reuters.

Pandemic days

From the earliest days of the pandemic, public health officials have expressed hope that it was possible to achieve herd immunity against COVID-19, as long as a high enough percentage of the population was vaccinated or infected with the virus.

Some health officials have revived the possibility of herd immunity since Omicron emerged late last year.

That adds to evidence that the coronavirus will continue to find ways to break through our immune defences, they said.

“Reaching a theoretical threshold beyond which transmission will cease is probably unrealistic given the experience we have had in the pandemic,” Dr Olivier le Polain, an epidemiologist with the World Health Organization (WHO), told Reuters.

That is not to say that prior immunity offers no benefit.

Widespread vaccination

“As long as population immunity holds with this variant and future variants, we’ll be fortunate and the disease will be manageable,” said Dr David Heymann, a professor of infectious disease epidemiology at the London School of Hygiene and Tropical Medicine.

But the clinical trial results in late 2020 showing that two of the vaccines had more than 90% efficacy against the disease initially sparked hope that the virus could be largely contained by widespread vaccination, similar to the way measles has been curbed by inoculation.

“The first is that immunity, especially to infection, which is the important kind of immunity, wanes quite quickly, at least from the vaccines that we have right now,” he said.

He cautioned against assuming that infection with Omicron would increase protection, especially against the next variant that might arise. 

“Just because you had Omicron, maybe that protects you from getting Omicron again, maybe,” Wohl said.

Pandemic to endemic

Vaccines in development that provide immunity against future variants or even multiple types of coronaviruses could change that, said Pasi Penttinen, the top influenza expert at the European Centre for Disease Prevention and Control, but it will take time.

Still, the hope for herd immunity as a ticket back to normal life is hard to shake.

Global health experts expect that the coronavirus will ultimately become endemic, circulating persistently in the population and causing sporadic surges.

The emergence of Omicron, however, has raised questions about exactly when that might happen.

“We will get there,” said the WHO’s le Polain, “but we are not there at the moment.”

Did you subscribe to our newsletter?

It’s free! Click here to subscribe! 

Source: Reuters