Can Americans COVID herd immunity by late spring? -Consumer Health News

Wednesday, February 24, 2021 (HealthDay News)-Are you hungry for good news about pandemics? One epidemiologist believes that Americans may soon reach herd immunity to the new coronavirus in late spring.

This is the view of Susanne Judd, a professor of public health at the University of Alabama at Birmingham. To reach that conclusion, she reviewed recent studies and data from her home state.

“I’m starting to feel like I’m starting to see the edge of the forest, like the light at the end of the tunnel,” Judd said in a media briefing Wednesday.

According to the US Centers for Disease Control and Prevention, herd immunity occurs when a sufficient number of people in the community are already ill or are protected from getting sick because they are vaccinated. ..

Scientists primarily believe that “a sufficient number of people” means 72% of Americans who develop immunity to the coronavirus, but warns that “there is no magic number of herd immunity.” doing.

Still, the trend unfolding in Alabama suggests that group immunity is on track to settle by late spring or early summer, she said.

Judd’s optimistic reading is based on two main considerations. One is the rate at which Alabama residents receive a second vaccination, which she inoculates about 50,000 people a week. This is what she calls a “conservative estimate.”

The other is the large number of people who are likely to already have coronavirus antibodies, even though they did not test positive.

For example, Judd, a recent Columbia University study led by infectious disease specialist Jeffrey Shaman (still awaiting peer review), found that the actual number of infected Americans was a pandemic.

The Colombian team also estimates that the actual number of active COVID-19 cases is probably 10 times higher than the official numbers indicate. Judd said this was probably due to inadequate testing.

Still, Judd’s optimism about Alabama’s outlook on spring herd immunity presupposes far less underestimation. Based on the 500,000 diagnoses confirmed so far in Alabama, Judd pegged the true number of cases across the state to 1.5 million, saying, “I have never tested positive for the virus and I have symptoms. Some people didn’t. “

Another concern is the possibility of future viral mutations. However, Judd emphasized that not all mutations impair acquired immunity. And if some people do, the response is vaccine regulation and boost immunization, “we always do something with the flu.”

With all this in mind, herd immunity becomes established when the number of new infections per week drops to 5 or 10 per 100,000 or less (and continues). “Then you’ll find it safe to get people back,” Judd said.

“True herd immunity will allow us to start coming back together again,” she said. “The problem was that [the new coronavirus] He sent many to the hospital and killed many. ”

However, the “weakly virulent and weakened” virus is another sign of herd immunity.

Dr. Amesh Adalja is a senior scholar at the Johns Hopkins Center for Health Security in Baltimore. Although not part of the UA briefing, he believes that at this point, “about one-third of the population is likely to be immune to natural infections and less immune to vaccination.” It’s a national figure emerged by a team at Columbia University.

Adalja agreed, “It is true that the current level of artificial immunity in the United States influences the spread of the coronavirus.” Still, he warned, “it will take some time before the herd immunity threshold is crossed.”

“But I don’t think that’s the only thing that matters,” Adalja added. “When vulnerable people are vaccinated, there will be increased pressure on hospitals, which will change the risk perception of the disease.”

Meanwhile, Judd warned that it would be premature to stop following the CDC’s guidance on social distance until herd immunity was established.

“If people stop wearing masks before the virus is controlled, that would definitely be a problem,” she said, noting that it is not yet known if the vaccine will stop the infection. “Therefore, even if you are vaccinated, you still need to wear a mask,” Judd advised.

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Source: Dr. Susanne Judd, Epidemiologist and Professor, Faculty of Public Health, University of Alabama at Birmingham.Ameshua Darja, Maryland, Senior Scholar, Johns Hopkins Center for Health Security, Baltimore; University of Alabama, Media Briefing, February 24, 2021