Trying to reach herd immunity to the coronavirus is ‘unethical’ and unprecedented, WHO head says

“Never in the history of public health has herd immunity been used as a strategy for responding to an outbreak, let alone a pandemic,” WHO Director-General Tedros Adhanom Ghebreyesus said at a Monday media briefing. “It is scientifically and ethically problematic.”

In a public health context, herd immunity typically describes a scenario in which a large enough share of the population is vaccinated against a disease to prevent it from spreading widely, thereby providing default protection to a minority of people who have not been vaccinated.

But as there is still no vaccine for the coronavirus, achieving herd immunity in the current environment would require a large number of people to contract the virus, survive covid-19, and then produce sufficient antibodies to provide long-term protection.

While the scientific community has roundly rejected herd immunity the approach, public interest in it has waxed and waned amid pressure to reopen schools and economies.

Last month, President Trump appeared to praise the idea during a town hall in Pennsylvania.

“You’ll develop herd — like a herd mentality,” he said. “It’s going to be — it’s going to be herd developed — and that’s going to happen.”

British Prime Minister Boris Johnson’s government initially expressed interest in the theory before backtracking amid public outcry over the dangers of letting the virus spread. Johnson himself was hospitalized with a severe case of covid-19, which he said could have killed him.

Tedros, noting that there had been “some discussion” about the concept recently, told reporters Monday that allowing people to be exposed to a deadly virus whose effects are still not fully known was “not an option.”

“Most people who are infected with the virus that causes covid-19 develop an immune response within the first few weeks, but we don’t know how strong or lasting that immune response is, or how it differs for different people,” he said.

Antibody studies suggest that less than 10 percent of people in most countries have contracted covid-19, Tedros said, which is nowhere near the majority that would be needed for herd immunity.

With the “vast majority” of the world’s population susceptible, letting the virus spread “means allowing unnecessary infections, suffering and death,” he said.

Just in the last four days, Tedros said Monday, the global coronavirus count has continued to break its daily record for the number of new confirmed infections.

“Many cities and countries are also reporting an increase in hospitalizations and intensive care bed occupancy,” he added.

Tedros has urged governments to pursue comprehensive plans that include widespread testing, social distancing, and other preventive measures, such as face-mask wearing, alongside a global push to develop a vaccine. The WHO is spearheading an effort to distribute coronavirus vaccines equitably once they are available, which Trump declined to join.

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COVID-19 again? Reinfection cases raise concerns over immunity

By Kate Kelland

LONDON (Reuters) – The case of a man in the United States infected twice with COVID-19 shows there is much yet to learn about immune responses and also raises questions over vaccination, scientists said on Tuesday.

The 25-year-old from Reno, Nevada, tested positive in April after showing mild symptoms, then got sick again in late May with a more serious bout, according to a case report in the Lancet Infectious Diseases medical journal.

The report was published just hours after U.S. President Donald Trump, who was infected with COVID-19 and hospitalised earlier this month, said he believes he now has immunity and felt “so powerful”.

Scientists said that while known incidences of reinfection appear rare – and the Nevada man has now recovered – cases like his were worrying. Other isolated cases of reinfection have been reported around the world, including in Asia and Europe.

In the Netherlands, the National Institute for Public Health confirmed on Tuesday that an 89-year-old Dutch woman, also sick with a rare form of bone marrow cancer, had recently died after contracting COVID-19 for a second time.

Dutch media said this was the first known case worldwide of a death after SARS-CoV-2 coronavirus reinfection.

‘IMPLICATIONS FOR VACCINATION’

“It is becoming increasingly clear that reinfections are possible, but we can’t yet know how common this will be,” said Simon Clarke, a microbiology expert at Britain’s Reading University.

“If people can be reinfected easily, it could also have implications for vaccination programmes as well as our understanding of when and how the pandemic will end.”

The Nevada patient’s doctors, who first reported the case in a non peer-reviewed paper in August, said sophisticated testing showed that the virus strains associated with each bout of infection were genetically different.

“These findings reinforce the point that we still do not know enough about the immune response to this infection,” said Paul Hunter, a professor in medicine at Britain’s University of East Anglia.

Brendan Wren, a professor of vaccinology at the London School of Hygiene & Tropical Medicine, said the Nevada case was the fifth confirmed example of reinfection worldwide. 

“The demonstration that it is possible to be reinfected by SARS-CoV-2 may suggest that a COVID-19 vaccine may not be totally protective,” he said. “However, given the (more than) 40 million cases worldwide, these small examples of reinfection are tiny and should not deter efforts to develop vaccines.”

World Health Organization spokesman Tarik Jasarevic concurred that the U.S. case underlined what was unknown about immunity. “And this also really is an argument against what some have been advocating, and that’s building naturally what is called herd immunity. Because we don’t know,” he told a briefing.

(Reporting by Kate Kelland; Additional reporting by Anthony Deutsch in Amsterdam, Stephanie Nebehay in Geneva; Editing by Andrew Cawthorne)

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Trump boasts of Covid-19 immunity at first rally since diagnosis

President Donald Trump boasted about his Covid-19 immunity as he held his first rally since his diagnosis.

Trump staged a vigorous return to the campaign trail Monday night as he walked to the podium in Sanford, Fla., without a mask, throwing campaign merchandise to the crowd. Just hours before he stepped on stage, Trump’s physician announced the president was no longer infectious after testing negative for consecutive days.

To prove his medical team’s point, Trump emphasized his good health to an audience where numerous maskless people could be spotted among the dense crowd: “It does give you a good feeling when you can beat something and now they say you’re immune,” he said at the hourlong rally.

“I feel so powerful,” he said. “I’ll walk into that audience. I’ll walk in there, I’ll kiss everyone in that audience. I’ll kiss the guys and the beautiful women.”

As Trump acknowledged the uncertainty surrounding the length of his immunity, he accused unspecified people of “reducing” the immunity period to make the virus seem more severe than it actually is. The uncertainty about the length (and strength) of immunity, however, is caused by the lack of information about the virus, which has been infecting humans for less than a year. Experts have only recently documented cases of people becoming reinfected.

The president also pointed out that medical professionals have a better grasp of the virus now than they did six months ago, and said that life would go back to normal — even as health experts warn that the United States could face 200,000 more deaths by 2021. And as he thanked Americans for staying resilient, the crowd chanted, “We love you.”

“I have such respect for the people of this country the way they’ve handled it,” he said. “It’s been an incredible love-fest together.”

And with his promise for normalcy, Trump emphasized that “the cure cannot be worse than the problem itself” as he praised Florida and Gov. Ron DeSantis, who was in the crowd, for opening up businesses and tourism. However, he failed to note that Florida now has the third-largest number of cases out of all of the U.S. states, with 5,570 new confirmed cases on Sunday.

As he pushed for the opening of the economy, he claimed that Democratic nominee Joe Biden would seek a “draconian unscientific lockdown” that would delay recovery for the state.

“When you’re the president, you can’t lock yourself in a basement and say, ‘I’m not gonna bother with the world,’” Trump said. “And it’s risky, but you’ve got to get out.”

In a speech filled with many of his most familiar applause and attack lines, Trump also boasted about the size of his crowd as he mocked Biden for his smaller gatherings.

Anthony Fauci, however, on Monday expressed his wariness about holding large political rallies during a pandemic.

“Put aside the political implications the rally has,” Fauci said on CNN. “Purely for public health, we know that’s asking for trouble when you

China Tests Entire City For Virus As WHO Slams Herd Immunity Idea

China rushed Tuesday to test an entire city of nine million within days after a minor coronavirus outbreak, as the WHO warned that letting the pathogen run free to achieve herd immunity was “scientifically and ethically problematic”.

The virus is still spreading rapidly around the world, with well over 37 million infections, and nations that had suppressed their first outbreaks are now struggling with fresh surges — especially in some parts of Europe.

China is rushing to test the entire population of Qingdao -- nine million people -- for the coronavirus China is rushing to test the entire population of Qingdao — nine million people — for the coronavirus Photo: AFP / STR

In the absence of a vaccine, governments are wary of allowing the virus to spread unchecked, with China launching a sweeping drive to test all residents of Qingdao after a handful of cases were detected on Sunday.

“As of 8 am… our city has taken 3.08 million samples for nucleic testing,” the city’s health commission said Tuesday, adding that no new positive samples were found.

Chinese officials intend to test the entire city — around 9.4 million people — by Thursday.

Graphic looking at countries with the highest coronavirus death tolls, and their respective death rates. Graphic looking at countries with the highest coronavirus death tolls, and their respective death rates. Photo: AFP / John SAEKI

In scenes contrasting with the fumbled testing efforts of other nations, health workers in protective clothing swiftly set up tents and residents queued deep into Monday night to provide samples.

In opposition to economically painful lockdowns and social distancing, there have been proposals in some countries to let the coronavirus circulate in the population to build up “herd immunity” — where so much of the population has been infected there are insufficient new victims for the virus to jump to.

Letting Covid-19 "run free" with eye to herd immunity is "simply unethical", says WHO Director General Tedros Adhanom Ghebreyesus in Geneva. Letting Covid-19 “run free” with eye to herd immunity is “simply unethical”, says WHO Director General Tedros Adhanom Ghebreyesus in Geneva. Photo: WHO

But the World Health Organization said such plans were unworkable, and required mass vaccinations to work.

“Herd immunity is achieved by protecting people from a virus, not by exposing them to it,” WHO chief Tedros Adhanom Ghebreyesus said Monday, describing the idea as “scientifically and ethically problematic”.

“Allowing a dangerous virus that we don’t fully understand to run free is simply unethical. It’s not an option.”

China is rushing to test the entire population of Qingdao -- nine million people -- for the coronavirus China is rushing to test the entire population of Qingdao — nine million people — for the coronavirus Photo: AFP / STR

Further illustrating the challenge, a study published in The Lancet Infectious Diseases journal indicated that exposure to the virus may not guarantee future immunity — and the second infection could come with even more severe symptoms.

A television shows Britain's Prime Minister Boris Johnson addressing the country on new virus restrictions, as customers sit at the bar inside the William Gladstone pub in Liverpool A television shows Britain’s Prime Minister Boris Johnson addressing the country on new virus restrictions, as customers sit at the bar inside the William Gladstone pub in Liverpool Photo: AFP / Paul ELLIS

The pandemic has claimed more than one million lives worldwide, and spurred breakneck efforts to develop vaccines and effective treatments.

Some have made it to late-stage clinical testing, but the optimism was dented Monday when Johnson & Johnson announced it had temporarily halted its

Covid-19 reinfection casts doubt on virus immunity: study

Covid-19 patients may experience more severe symptoms the second time they are infected, according to research released Tuesday confirming it is possible to catch the potentially deadly disease more than once.

A study published in The Lancet Infectious Diseases journal charts the first confirmed case of Covid-19 reinfection in the United States — the country worst hit by the pandemic — and indicates that exposure to the virus may not guarantee future immunity.

The patient, a 25-year-old Nevada man, was infected with two distinct variants of SARS-CoV-2, the virus that causes Covid-19, within a 48-day time frame. 

The second infection was more severe than the first, resulting in the patient being hospitalised with oxygen support.

The paper noted four other cases of reinfection confirmed globally, with one patient each in Belgium, the Netherlands, Hong Kong and Ecuador. 

Experts said the prospect of reinfection could have a profound impact on how the world battles through the pandemic.

In particular, it could influence the hunt for a vaccine — the currently Holy Grail of pharmaceutical research. 

“The possibility of reinfections could have significant implications for our understanding of Covid-19 immunity, especially in the absence of an effective vaccine,” said Mark Pandori, for the Nevada State Public Health Laboratory and lead study author. 

“We need more research to understand how long immunity may last for people exposed to SARS-CoV-2 and why some of these second infections, while rare, are presenting as more severe.”

– Waning immunity? –

Vaccines work by triggering the body’s natural immune response to a certain pathogen, arming it with antibodies it to fight off future waves of infection.

But it is not at all clear how long Covid-19 antibodies last. 

For some diseases, such as measles, infection confers lifelong immunity. For other pathogens, immunity may be fleeting at best. 

The authors said the US patient could have been exposed to a very high dose of the virus the second time around, triggering a more acute reaction. 

Alternatively, it may have been a more virulent strain of the virus. 

Another hypothesis is a mechanism known as antibody dependent enhancement — that is, when antibodies actually make subsequent infections worse, such as with dengue fever.

The researchers pointed out that reinfection of any kind remains rare, with only a handful of confirmed cases out of tens of millions of Covid-19 infections globally.

However, since many cases are asymptomatic and therefore unlikely to have tested positive initially, it may be impossible to know if a given Covid-19 case is the first or second infection.

In a linked comment to The Lancet paper, Akiko Iwasaka, a professor of Immunobiology and Molecular, Cellular and Developmental Biology at Yale University, said the findings could impact public health measures.

“As more cases of reinfection surface, the scientific community will have the opportunity to understand better the correlates of protection and how frequently natural infections with SARS-CoV-2 induce that level of immunity,” she said.

“This information is key to understanding which vaccines are capable of

Herd immunity strategy is ‘simply unethical,’ says WHO

The head of the World Health Organization warned against the idea that herd immunity might be a realistic strategy to stop the pandemic, dismissing such proposals as “simply unethical.”

At a media briefing on Monday, WHO Director-General Tedros Adhanom Ghebreyesus said health officials typically aim to achieve herd immunity by vaccination. Tedros noted that to obtain herd immunity from a highly infectious disease such as measles, for example, about 95 percent of the population must be immunized.

“Herd immunity is achieved by protecting people from a virus, not by exposing them to it,” he said. Some researchers have argued that allowing COVID-19 to spread in populations that are not obviously vulnerable will help build up herd immunity and is a more realistic way to stop the pandemic, instead of the restrictive lockdowns that have proved economically devastating.

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“Never in the history of public health has herd immunity been used as a strategy for responding to an outbreak,” Tedros said.

Tedros said that too little was known about immunity to COVID-19 to know if herd immunity is even achievable.

“We have some clues, but we don’t have the complete picture,” he said, noting that WHO had documented instances of people becoming reinfected with coronavirus after recovering from an initial bout of the virus. Tedros said that while most people appear to develop some kind of immune response, it’s unclear how long that lasts or how robust that protection is — and that different people have varying responses.

“Allowing a dangerous virus that we don’t fully understand to run free is simply unethical,” he said.

WHO estimates less than 10 percent of the population has any immunity to the coronavirus, meaning the vast majority of the world remains susceptible.

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Tedros also noted countries had reported record-high daily figures of COVID-19 to the U.N. health agency for the last four days, citing surges in Europe and the Americas in particular.

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UN warns against pursuing herd immunity to stop coronavirus

The head of the World Health Organization warned against the idea that herd immunity might be a realistic strategy to stop the pandemic, dismissing such proposals as “simply unethical.”

LONDON — The head of the World Health Organization warned against the idea that herd immunity might be a realistic strategy to stop the pandemic, dismissing such proposals as “simply unethical.”

“Herd immunity is achieved by protecting people from a virus, not by exposing them to it,” he said. Some researchers have argued that allowing COVID-19 to spread in populations that are not obviously vulnerable will help build up herd immunity and is a more realistic way to stop the pandemic, instead of the restrictive lockdowns that have proved economically devastating.

Tedros said that too little was known about immunity to COVID-19 to know if herd immunity is even achievable.

“Allowing a dangerous virus that we don’t fully understand to run free is simply unethical,” he said.

WHO estimates less than 10% of the population has any immunity to the coronavirus, meaning the vast majority of the world remains susceptible.

Tedros also noted countries had reported record-high daily figures of COVID-19 to the U.N. health agency for the last four days, citing surges in Europe and the Americas in particular.

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Trump advisers consult scientists pushing disputed herd immunity strategy

Mainstream medical and public health experts say that seeking widespread, or herd, immunity in the manner the scientists prescribe could result in the deaths of hundreds of thousands or even millions more U.S. residents.

The trio, who Azar described as “three distinguished infectious disease experts,” favors moving aggressively to reopen the economy while sidelining broad testing and other fundamental public health measures. “Three months, maybe six is sufficient time for enough immunity to accumulate … that the vulnerable could resume normal lives,” Gupta said Monday night in appearance on Laura Ingraham’s Fox News show.

That aligns with the “herd-immunity” strategy endorsed by Atlas, who Bhattacharya said was their “point of contact” for the meeting. Atlas, a neuroradiologist and senior fellow at Stanford University’s Hoover Institution, has emerged as a favored adviser to the president despite his lack of expertise in public health, infectious disease or epidemiology, and his skepticism of basic safety measures like wearing masks.

HHS refused to comment on the scientists’ meeting with Azar and Atlas’ role in it, or whether the Trump administration is shifting to a herd immunity strategy.

Studies by the CDC and academic scientists have concluded that fewer than 10 percent of Americans had antibodies to the virus by July. That’s far fewer than the 60 to 70 percent infection rate most experts believe is needed to achieve herd immunity. They say that getting there without a vaccine would dramatically increase the Covid-19 death toll and leave a large number of Americans with lasting health problems.

Given those facts, Azar’s tweet set off alarm bells among public health experts worried that the administration is pushing a return to normal life before the virus is contained or a vaccine is available.

“This is not a good faith attempt to talk to experts. This is an attempt to cherry pick credentialed people who happen to agree with the administration’s political instincts or political inclinations,” said Jeremy Konyndyk, a former Obama administration official who oversaw disaster response.

The scientists who met with Azar have repeatedly advanced questionable theories about the virus’ risks and the impact of lockdowns.

Bhattacharya co-authored a study with colleagues at Stanford that suggested the coronavirus infection rate was up to 85 percent higher in Silicon Valley than previously estimated, suggesting that the virus was not nearly deadly enough to justify continued lockdowns.

The analysis, released in April without undergoing peer review, quickly came under attack from other scientists who questioned the accuracy of the antibody test used in the study, and the authors’ research methods — which included recruiting participants through Facebook and social contacts of the scientists, raising the risk of an unrepresentative sample.

Bhattacharya and his colleagues revised the study’s findings just two weeks after they released it, reducing their projection of how many people had been infected by one-third.

Across the pond, Gupta and colleagues in her Oxford research group opposed the stringent lockdown orders the U.K. imposed in March, arguing at the time that “the death rate or the

Corralling the Facts on Herd Immunity

Editor’s note: Find the latest COVID-19 news and guidance in Medscape’s Coronavirus Resource Center.

For a term that’s at least 100 years old, “herd immunity” has gained new life in 2020.



KHN

It starred in many headlines last month, when reports surfaced that a member of the White House Coronavirus Task Force and adviser to the president, Dr. Scott Atlas, recommended it as a strategy to combat COVID-19. The Washington Post reported that Atlas, a health care policy expert from the Hoover Institution of Stanford University, suggested the virus should be allowed to spread through the population so people build up immunity, rather than trying to contain it through shutdown measures.

At a town hall event a few weeks later, President Donald Trump raised the idea himself, saying the coronavirus would simply “go away,” as people developed “herd mentality” — a slip-up that nonetheless was understood to reference the same concept.

And as recently as last week, Sen. Rand Paul (R-Ky.) sparked a heated debate at a committee hearing when he suggested that the decline in COVID cases in New York City was due to herd or community immunity in the population rather than public health measures, such as wearing masks and social distancing. Dr. Anthony Fauci, the top U.S. infectious disease official, rebuked Paul, pointing out that only 22% of the city’s residents have COVID antibodies.

“If you believe 22% is herd immunity, I believe you’re alone in that,” Fauci told the senator.

All this talk got us thinking: People seem pretty confused about herd immunity. What exactly does it mean and can it be used to combat COVID-19?

An Uncertain Strategy With Great Cost

Herd immunity, also called community or population immunity, refers to the point at which enough people are sufficiently resistant to a disease that an infectious agent is unlikely to spread from person to person. As a result, the whole community — including those who don’t have immunity — becomes protected.

People generally gain immunity in one of two ways: vaccination or infection. For most diseases in recent history — from smallpox and polio to diphtheria and rubella —vaccines have been the route to herd immunity. For the most highly contagious diseases, like measles, about 94% of the population needs to be immunized to achieve that level of protection. For COVID-19, scientists estimate the percentage falls between 50% to 70%.

Before the COVID pandemic, experts can’t recall examples in which governments intentionally turned to natural infection to achieve herd immunity. Generally, such a strategy could lead to widespread illness and death, said Dr. Carlos del Rio, an expert in infectious disease and vaccines at the Emory University School of Medicine.

“It’s a terrible idea,” del Rio said. “It’s basically giving up on public health.”

A new, large study found fewer than 1 in 10 Americans have antibodies to SARS-CoV-2, the virus that causes COVID-19. Even in the hardest-hit areas, like New York City, estimates of immunity among residents are about 25%.

To reach 50% to