Omicron: Natural immunity idea ‘not really panning out,’ doctor explains

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The Omicron strain of the coronavirus is fueling a rapid surge in confirmed COVID-19 cases — including among vaccinated and even boosted Americans — and a new rise in hospitalizations among unvaccinated Americans is further weakening the notion that natural immunity alone provides adequate protection amid the evolving pandemic.

“This idea of natural immunity is not really panning out with this virus,” Dr. Hilary Fairbrother, an emergency medicine physician based in Houston, TX, said on Yahoo Finance Live (video above). “I think part of that is because Omicron has so many mutations, and there’s really no way to know what the next variant will have.”

The U.S. is nearing 60 million confirmed cases and is averaging more than 500,000 new confirmed cases a day over the last week, raising new questions about whether the U.S. will be able to reach herd immunity.

“I think the problem with herd immunity is that is really taking into account that this virus won’t mutate significantly and we might not have a very significant variant roaming around that has nothing to do with omicron that really doesn’t see any natural immunity from people who have been sick with omicron,” Fairbrother said, adding that "that's kind of what we saw with" previous variants.

'Next to no immunity' with omicron

When it comes to natural immunity, relying on prior natural infection over vaccination can come at a cost — and it doesn't seem to work currently given the evasive capabilities of Omicron.

Millions of Americans are suffering from long COVID (long-term effects of coronavirus), which can range from mild symptoms like loss of taste and smell to more serious problems like tachycardia and extreme fatigue, and unvaccinated Americans are 20 times as likely to die from the virus.

“For patients who had alpha or delta [strains of coronavirus], they seem to have next to no immunity when it comes to omicron,” Fairbrother said. “There is some evidence that there’s slightly less severity in disease, and other people have certainly seen patients who are very sick with omicron who have already had COVID. So the best protection that we have is vaccination.”

Currently, 62.4% of the U.S. population is fully vaccinated, 74% have received at least one dose, and 35.3% of the fully vaccinated have been boosted, according to CDC data.

'We're in a tough place'

Natural immunity, like immunity provided by vaccines, also wanes over time.

That means a person can get reinfected and then spread the virus to others, further endangering those who are immunocompromised or not yet eligible for booster shots, such as children.

“Unfortunately for children under five, that’s not an option,” Fairbrother said. “So we’re really seeing this younger child group pay the price of continued coronavirus sweeping our country. Such a large volume of cases means that some of those children are going to get very sick and that they’re going to need hospitalization. That’s really tragic.”

A protester, who identified herself as a school teacher, demonstrates against the mandate that teachers and staff in the NYC Schools system be vaccinated against COVID, in New York City, October 4, 2021. REUTERS/Brendan McDermid
A protester, who identified herself as a school teacher, demonstrates against the mandate that teachers and staff in the NYC Schools system be vaccinated against COVID, in New York City, October 4, 2021. REUTERS/Brendan McDermid

According to the American Academy of Pediatrics, nearly 7.9 million children have tested positive for COVID, with over 325,000 cases for the week ending Dec. 30., a 64% increase from the week prior.

“Since those children [under 5] aren’t eligible by age to be vaccinated yet, they really have no other protection except for all of us, hopefully protecting ourselves and decreasing the spread of this very contagious disease,” Fairbrother said.

And aside from protecting children from getting the virus, increasing vaccination uptake also means decreasing the risk of those children spreading it to others in schools, like teachers or other administrative employees.

“Certainly, I’ve heard of schools having to shut down because there aren’t enough teachers and administrators to keep them open,” Fairbrother said. “So I think we’re in a tough place. And there are some communities that really might have to go to virtual learning, which is terrible for everyone, and I think really should only be used as a last resort option when everything else has failed."

The “no-brainer” way to prevent this, she said, is to ensure that all students and teachers are masked up in schools. As of September 2021, 17 states mandate masks to be worn in schools while eight states have outright banned school mask mandates.

“If children aren’t wearing masks and we’re not doing everything with testing that we can do to mitigate any outbreaks that occur within our school systems, I don’t know how we can even expect there to be teachers or other staff to keep schools open, period,” Fairbrother said.

All things considered, according to Fairbrother, the best protection is to follow the core public health guidelines: get vaccinated, social distance, wash your hands, and wear a mask in public.

“Then from there, hopefully with the next variant, things will keep being mild,” she said.

Adriana Belmonte is a reporter and editor covering politics and health care policy for Yahoo Finance. You can follow her on Twitter @adrianambells and reach her at

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