Experts say herd immunity against COVID-19 will be difficult to achieve unless more of the world gets vaccinated. Lana Stock/Getty Images

• Experts say herd immunity is an increasingly elusive goal when it comes to COVID-19.
• While the United States is making progress in vaccinations, there is still a long way to go.
• Globally, a small percentage of people have been vaccinated.
• Until a majority of Americans are vaccinated, it is still best to follow mask-wearing and physical distancing guidelines.

For a nation weary of the COVID-19 pandemic, the promise of vaccinations — and, eventually, herd immunity — has been the light at the end of the tunnel.

More than all people in the United States and more than half of adults have received at least one dose of vaccine.

However, herd immunity, which would cause the coronavirus to disappear, remains a trickier proposition

And one which, according to experts, seems increasingly unlikely.

How does it work?

“Herd immunity is the idea that once a certain percentage of the population is immune to an infection, the infection can no longer spread within the population,” explained PlushCare’s chief medical officer , a virtual primary care provider.

“The idea is that even if 100% of the population is not immune, there are not enough people left to spread it for the infection to persist, which means it simply disappears from the population over time. time. “That’s how we eradicated some infections, like smallpox, through a mass vaccination program,” Wantuck told Healthline.

So far, the vaccination program in the United States has been successful.

And while the prospect of the coronavirus extinction through a combination of vaccinations and herd immunity is appealing, the nation's top doctor is urging caution.

Earlier this month, Dr. Anthony Fauci in a White House briefing that, in the context of COVID-19, it is difficult to define what exactly would constitute herd immunity.

“Rather than focusing on an elusive number, let’s get as many people vaccinated as quickly as possible,” Fauci said.

A global pandemic

Analyzing the numbers through an American lens shows clear signs of progress. But global numbers are another story.

, the health officer for Project HOPE and a trained epidemiologist at the Centers for Disease and Control and Prevention (CDC) who spent more than 20 years at the CDC, told Healthline that vaccinations work.

But he noted that we have a long way to go.

“We should not be misled by this early national progress when the majority of Americans remain unvaccinated – and only 3% of the world's population has been fully vaccinated,” he said.

Kenyon noted that at current vaccination rates, only 10 percent of people in the majority of developing countries will be vaccinated next year.

“Global vaccine inequity must be addressed because it is the right thing to do from a humanitarian perspective, but also to prevent the global proliferation of other variants that threaten the usefulness of diagnostic tests, current therapies and vaccines,” he said.

Due to the slow pace of vaccinations in much of the world and the emergence of coronavirus variants, it seems increasingly unlikely that herd immunity can stop the coronavirus in its tracks.

While it's understandable that people want to return to a sense of normalcy, experts say the best practice is to continue in pandemic mode for the time being.

Kenyon said everyone who can get vaccinated should do so as soon as possible while continuing to wear masks and physically distance from unvaccinated people.

“One thing is clear: This pandemic is far from over,” Kenyon said. “Overwhelming waves of new cases are on the horizon if we behave recklessly, such as the recent lifting of mandatory mask mandates by some governors and the large public gatherings we attended over spring break. »

“Recurring spikes in cases have always followed premature abandonment of public health precautions,” he added. “Hospital beds are filling to capacity again, which is why health experts are pleading with U.S. residents to wear masks and socially distance from others until most people are vaccinated . »

Kenyon concluded by emphasizing that the pandemic cannot be controlled locally if it is not controlled globally.

“It is dangerous for a country or a community to behave as if it is clear if the science, the numbers and the facts say otherwise,” he said.

“It is not only our human imperative to make vaccines available to all countries more quickly and in sufficient quantities,” Kenyon said, “but also our only viable way out of this global health crisis.”

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