Scientists alarmed at spread of Covid mutant

 New strain of virus is 70 per cent more transmissible but seemingly no more deadly after its detection in UK and elsewhere

B.1.1.7 is fast supplanting other strains of the SARS-COV-2 virus © NIAID

Clive Cookson

The highly infectious variant of coronavirus that has emerged in south-east England is spreading rapidly to the rest of the UK and is already present elsewhere in the world, scientists warned on Sunday.  

  The World Health Organisation said its Evolution Working Group is working closely with the UK medical authorities to understand how the variant, now called B.1.1.7, is likely to affect the course of the pandemic. It has been detected in the Netherlands, Denmark and Australia. Scientists say two aspects of B.1.1.7 give cause for concern. One is the unprecedented number of mutations it carries. 

The other is the speed with which it is supplanting other strains of the Sars-Cov-2 virus in south-east England. Jeffrey Barrett, director of the Covid Genomics Initiative at the Wellcome Sanger Institute, said 23 letters in the viral genetic code had changed, of which 17 might affect the behaviour of the virus — in particular helping it to enter and propagate within human cells. “This new variant is very concerning, and is unlike anything we have seen so far in the pandemic,” he said.

There is no evidence so far that the mutations are affecting the course of the illness in people who are infected with B.1.1.7 or the effectiveness of Covid-19 vaccines under development. “Hospitalisation rates have gone up recently [in south-east England] but roughly in line with the increase in case numbers, which doesn’t point to the new strain leading to more severe symptoms” said François Balloux, director of the UCL Genetics Institute in London.

 “I’d be very surprised if any evidence arose that it creates more serious symptoms,” Prof Balloux added. “It’s also not a strain that should be able to escape protection provided by immunisation caused by the current vaccines or prior infection.” But Kristian Andersen, director of infectious disease genomics at Scripps Research Institute in California, said: “I have seen many articles stating ‘no effect on immunity or vaccines or clinical features. That is not correct . . . The fact is we don’t know but we will in coming weeks.” 

Regular Covid-19 tests do not detect viral mutations. Variants can only be identified through a readout of all 30,000 letters of genetic code in each Sars-Cov-2 sample using specialised sequencing machines. © Leon Neal/Getty 

Scientists at the UK government’s Porton Down microbiology labs and elsewhere are working hard to understand whether and if so how the mutations affect the severity of disease and the body’s immune response as well as viral transmissibility. The increased infectivity of the variant is illustrated by the fact that, after appearing in Kent on September 20, it was responsible for 28 per cent of infections in London by early November and 62 per cent in the week ending December 9. 

 Computer modelling suggests that it is 70 per cent more transmissible than other Sars-Cov-2 strains circulating in the UK and raises the R value — the average number of people to whom someone with Covid-19 passes the infection — by 0.4, which makes the pandemic far harder to control without stringent lockdown measures. According to a paper released on Saturday by the Covid-19 Genomics Consortium UK, labs have sequenced 1,623 Sars-Cov-2 viral genomes showing the B.1.1.7 variant. 

These include 519 in London, 555 in Kent, 545 elsewhere in the UK including Scotland and Wales, and four in other countries. Regular Covid-19 tests do not detect viral mutations. Variants can only be identified through a readout of all 30,000 letters of genetic code in each Sars-Cov-2 sample using specialised sequencing machines. 

 “The UK and Denmark are the [world’s] most regular and prolific sequencers,” pointed out Emma Hodcroft, a viral geneticist at the University of Bern in Switzerland. “So the variant could be elsewhere and not detected yet. More co-ordinated sequencing efforts regionally and globally would help us monitor variants.

ll viruses mutate and B.1.1.7 is not the first variant to cause concern. Examples include the D614G mutation that emerged early in the pandemic and moderately increases the transmissibility of Covid-19. That strain spread from Spain to the rest of Europe over the summer. The Y453F mutation arose in Danish mink but has not spread widely in other countries. 

 The strain now causing most international concern, besides B.1.1.7, is a different variant in South Africa called 501.V2. Professor Salim Abdool Karim, leader of the country’s Covid-19 programme, said on Friday: “We did not expect the rapid way in which this variant has become dominant in South Africa . . . 

We are finding between 80 and 90 per cent of the virus is this 501.V2 mutant.” Prof Karim said 501. V2 is increasing the “viral load” — the amount of virus present in patients — “which may translate to a higher efficiency of transmission.” Preliminary findings in the UK suggest that B.1.1.7 is having a similar effect.

Additional reporting: Donato Paolo Mancin.

Scientists alarmed at spread of Covid mutant

Here’s What People With Allergies Should Know About Covid Vaccines

 Four people so far have had allergic reactions after getting the Pfizer-BioNTech vaccine. Experts say that shouldn’t deter most people from getting a jab.

Vaccinations underway in Orange, Calif., on Wednesday.Credit...Jenna Schoenefeld for The New York Time.

By Katherine J. Wu

Allergic reactions reported in two health workers who received a dose of Pfizer’s vaccine in Alaska this week have reignited concerns that people with a history of extreme immune flare-ups might not be good candidates for the newly cleared shots.

The two incidents follow another pair of cases in Britain. Three of the four were severe enough to qualify as anaphylaxis, a severe and potentially life-threatening reaction. But all four people appear to have recovered.

Health officials on both sides of the pond are vigilantly monitoring vaccinated people to see if more cases emerge. Last week, British drug regulators recommended against the use of Pfizer’s vaccine in people who have previously had anaphylactic reactions to food, medicines or vaccines.

And on Thursday, Dr. Doran Fink, deputy director of the Food and Drug Administration’s clinical division of vaccines and related products applications, addressed the issue during a meeting about the vaccine made by Moderna that contains similar ingredients and is expected to soon receive emergency use authorization, or E.U.A., from the agency.

“We anticipate that there may be additional reports, which we will rapidly investigate,” Dr. Fink said, adding that robust surveillance systems were in place to detect these rare events.

Still, Dr. Fink said that “the totality of data at this time continue to support vaccinations under the Pfizer E.U.A., without new restrictions.”

The F.D.A., he added, would work with Pfizer to revise fact sheets and prescribing information for the vaccine so that the public would understand the risk of allergic reactions and know how to report them.

What do we know about the people who had bad reactions?

The first two confirmed cases of allergic reactions came from two health care workers in Britain. Both had a medical history of serious allergic reactions, but had not previously been known to have trouble with any of the vaccine’s ingredients. After an injection of epinephrine — the typical treatment for anaphylaxis — both recovered.

(A third British incident described as a “possible allergic reaction” was also reported and appears to have been minor.)

On Wednesday, two health workers in Alaska experienced reactions as well. One was too mild to be deemed anaphylaxis. But the other, which occurred in a middle-aged woman with no history of allergies, was serious enough to warrant hospitalization, even after she got a shot of epinephrine.

“What is happening does seem really unusual to me,” said Dr. Kimberly Blumenthal, an allergist, immunologist and drug allergy researcher at Massachusetts General Hospital. Vaccine-related allergic reactions are typically rare, occurring at a rate of about one in a million.

Dr. Blumenthal also pointed out that it was a bit bizarre to see allergic reactions clustering in just two locations: Britain and Alaska. Zeroing in on the commonalities between the two hot spots, she said, might help researchers puzzle out the source of the problem.

Do we know for sure that their reactions were caused by the vaccine?

British and U.S. agencies are investigating the causes, but no official has declared a direct link.

But Dr. Blumenthal suspects they were connected to the shots, because the reactions were immediate, occurring within minutes of injection.

“ We have to think it was related because of the timing,” she said.

Nor is it known if a particular ingredient might have been the cause. Pfizer’s vaccine contains just 10 ingredients. The most important is a molecule called messenger RNA, or mRNA — genetic material that can instruct human cells to make a coronavirus protein called spike. Once manufactured, spike teaches the immune system to recognize the coronavirus so it can be fought off in the future. Messenger RNA, which is naturally found in human cells, is unlikely to pose a threat, and degrades within about a day of being injected.

The other nine ingredients are a mix of salts, fatty substances and sugars that stabilize the vaccine. None are common allergens. The only chemical with a history of causing allergic reactions is polyethylene glycol, or PEG, which helps package the mRNA into an oily sheath, protecting it as it goes into human cells.

But PEG is, generally speaking, inert and widespread. It’s found in ultrasound gel, laxatives like Miralax and injectable steroids, among other drugs and products, Dr. Blumenthal said. Despite the chemical’s ubiquity, she said, “I’ve only seen one case of a PEG allergy — it’s really, really uncommon.”

It’s still possible that something else could be causing the reactions — perhaps a factor related to how the vaccines are transported, thawed or administered, Dr. Blumenthal said.

In an email, Steven Danehy, a spokesperson for Pfizer, said the company was working with health authorities to assess the situation in Alaska, and would keep close tabs on any subsequent reactions.

“Reports of adverse events outside of clinical studies are a very important component to our pharmacovigilance activities and we will review all available information on this case and all reports of adverse events following vaccination,” Mr. Danehy said.

Did the volunteers in Pfizer’s clinical trials have any bad reactions?

A small number of volunteers in Pfizer’s clinical trials experienced allergic reactions. Just one of the 18,801 participants who received the vaccine in a late-stage trial had anaphylaxis, and the incident was deemed unrelated to the vaccine, said Steven Danehy, a spokesman for Pfizer. No severe reactions were found in people who got a placebo shot.

Pfizer excluded people with a history of anaphylaxis to vaccines from its clinical trials.

What does the F.D.A. say about these reactions?

Several experts raised concerns about the allergic reactions in meetings convened to discuss both Pfizer’s and Moderna’s vaccines. The agency has advised caution, noting that health care providers should not administer the vaccine to anyone with a “known history of a severe allergic reaction” to any component of the vaccine — a standard warning for vaccines.

Should people with mild allergies wait to get vaccinated?

There’s no evidence that people with mild allergies, which are quite common, need to avoid the vaccine. Allergies are, simply put, the product of an inappropriate immune response against something harmless — pollen, peanuts, cat dander and the like. In many cases, the results of this overreaction are mild symptoms such as a runny nose, coughing or sneezing.

But allergies are specific: A reaction to one substance does not guarantee a reaction to another. On Monday, the American College of Allergy, Asthma and Immunology released guidance stating that people with common allergies “are no more likely than the general public to have an allergic reaction to the Pfizer-BioNTech Covid-19 vaccine.

William Amarquaye, a clinical pharmacist at Brandon Regional Hospital, said he wouldn’t let his asthma or allergies stop him from taking the vaccine when it is offered to him in the next few weeks. He’s also never had trouble with other vaccines he has taken in the past.

“It should still be OK to take the vaccine,” Dr. Amarquaye said. “I’m actually excited about it.”

What about people with a history of severe allergies?

Most people in this category should be good to go, too, said Dr. Eun-Hyung Lee, an expert in allergy and immunology at Emory University.

Guidelines released by the Centers for Disease Control and Prevention identify only one group of people who might not want to get Pfizer’s vaccine: those with a known history of severe allergic reactions to an ingredient in the injection.

People with a history of anaphylaxis to any other substance, including other vaccines or injectable drugs, can still get the vaccine, but should consult their health care providers and be monitored for 30 minutes after getting their shots. Everyone else, like people with mild or no allergies, need to wait only 15 minutes before leaving the vaccination site.

“In general, the immediate reactions that require epinephrine are those that happen within the first 30 minutes,” said Dr. Merin Kuruvilla, an allergist and immunologist at Emory University.

Some people will understandably be concerned. Dr. Taison Bell, a critical care physician at UVA Health in Charlottesville, Va., said he worried about his 7-year-old son, Alain, who is severely allergic to several foods, including wheat, peanuts and cow’s milk. Alain has about two bouts of anaphylaxis each year.

It’s a bit of a relief that Alain is “later in the prioritization schema,” Dr. Bell said. By the time a vaccine is ready for him, he said, “we’ll get a better sense for how serious this is.” The family plans to discuss their situation with Alain’s doctor.

Ultimately, it’s unlikely that any of the ingredients in a coronavirus vaccine would cause Alain any issues. Alain has tolerated other vaccines, including the flu shot, in previous years, and is looking forward to his own shot at immunization to the coronavirus, said Dr. Bell, who received his first dose of Pfizer’s vaccine on Tuesday.

What about Moderna’s vaccine?

Two volunteers in Moderna’s late-stage clinical trial developed anaphylactic reactions, the company reported at the F.D.A. committee meeting on Thursday. Neither was deemed to be linked to the company’s vaccine, which also contains mRNA, because they occurred weeks or months after the participants received their shots. One of these volunteers also had a history of asthma and a shellfish allergy.

Moderna, unlike Pfizer, did not exclude people with a history of anaphylaxis from its trials.

Dr. Tal Zaks, the company’s chief medical officer, said that while Moderna’s vaccine recipe was similar to Pfizer’s, key molecular differences existed that could set the two products on different paths. He said that bad reactions to Pfizer’s vaccine did not guarantee that similar events would happen in relation to the Moderna shots.

Both vaccines do, however, include a version of PEG.

Dr. Blumenthal and others said that anyone concerned about having an allergic reaction to a vaccine should seek the advice of a health care provider.

For anyone getting the vaccine, it’s all about “balancing out the risks,” Dr. Lee, of Emory, said. Allergic reactions can be dangerous. But they are rare and treatable, and the tools to combat them should be available at all vaccination sites. The coronavirus, on the other hand, can have far graver consequences.

“When it’s my turn in line, I think weighing these odds is what I would do,” Dr. Lee said.

Katherine J. Wu is a reporter covering science and health. She holds a Ph.D. in microbiology and immunobiology from Harvard University. @KatherineJWu

 A version of this article appears in print on Dec. 19, 2020, Section A, Page 11 of the New York edition with the headline: What You Need to Know About the Vaccines and Allergies. Order Reprints | Today’s Paper | Subscribe

Here’s What People With Allergies Should Know About Covid Vaccines

US administers 1st doses of Pfizer coronavirus vaccine

 The rollout of the first coronavirus vaccine began Monday morning as the first doses of the Pfizer medication was administered to health care workers and nursing home staffers.

© ABC News Sandra Lindsay, RN, a critical care nurse at Long Island Jewish Medical Center is the first person to be vaccinated in New York, Dec. 14, 2020.

A doctor from Northwell LIJ Medical Center on Long Island was vaccinated at 9:23 a.m. during a livestreamed event with New York Gov. Andrew Cuomo. "You didn't flinch," Cuomo said.

© ABC News Sandra Lindsay, RN, a critical care nurse at Long Island Jewish Medical Center is the first person to be vaccinated in New York, Dec. 14, 2020.

The University of Louisville Hospital in Kentucky will receive its first delivery of the vaccine at 9:30 a.m. and at 10:30 a.m., three doctors and two nurses will receive the vaccine.

Other locations in Connecticut, New York, Iowa, Washington, D.C., and Michigan are also expected to administer vaccine doses on Monday.

MORE: A breakdown of the Pfizer vaccine and why most people will qualify for the injection

The rollout comes less than a week after the U.S. Food and Drug Administration authorized the vaccine for emergency use for Americans over 16. The order from the FDA led to the pharmaceutical company shipping 2.9 million doses to 636 sites across the country.

© Rey Del Rio/Getty Images Shipments of the Pfizer-BioNTech COVID-19 vaccine are loaded into a UPS plane on Dec. 13, 2020 in Lansing, Michigan.

Pfizer, which produced the vaccine alongside German company BioNTech, began shipping the doses from its Michigan warehouse Sunday directly to those sites, which were pre-selected by governors and local health officials.

Pfizer said it would roll out a second batch of 2.9 million doses shortly after the first batch. The U.S. government is opting to keep 500,000 doses in reserve to address any shipping or distribution mishaps.

The vaccine, which requires two doses for full inoculation, began distribution in the United Kingdom last week.

The vaccine is the first in the country to use the genetic technology mRNA instead of viral components. Pfizer claimed its trials showed the vaccine was 95% effective at preventing symptomatic COVID-19.

© Morry Gash/Reuters Boxes containing the Pfizer-BioNTech COVID-19 vaccine are prepared to be shipped at the Pfizer Global Supply Kalamazoo manufacturing plant in Portage, Michigan, Dec. 13, 2020.

The FDA will hold a hearing on Dec. 17 with Moderna, which also developed an mRNA-based vaccine, before possibly giving emergency authorization for its deployment.

Moderna said its clinical trials showed the vaccine was 94% effective at preventing the coronavirus and trial patients who had the vaccine had elevated antibodies in their system three months after the vaccines were administered.

According to the World Health Organization, there are 52 COVID-19 vaccines in human trials, and 162 vaccines in preclinical development.

The vaccine developments come as the U.S. is in the midst of the deadliest period of the pandemic, according to health data. America leads the world with over 16 million cases and close to 300,000 deaths, according to Johns Hopkins University's Coronavirus Resource Center.

The seven-day averages of new daily cases, 211,494, hospitalizations, 106,656, and deaths, 2,427, were at record highs on Dec. 13, according to health data from the COVID Tracking Project.

ABC News' Arielle Mitropoulos, Sony Salzman and Eric Strauss contributed to this report.

This report was featured in the Monday, Dec. 14, 2020, episode of “Start Here,” ABC News’ daily news podcast.

“Start Here" offers a straightforward look at the day's top stories in 20 minutes. Listen for free every weekday on Apple Podcasts, Google Podcasts, Spotify, the ABC News app or wherever you get your podcasts.

US administers 1st doses of Pfizer coronavirus vaccine

F.D.A. Advisory Panel Gives Green Light to Pfizer Vaccine

 The blessing of these experts means that the agency will likely OK the vaccine’s use, paving the way for health care workers to begin getting shots next week.

Vaccinations were underway in Britain as the F.D.A.’s advisory panel met on Thursday.Credit...Pool photo by Victoria Jone.

By Katie Thomas, Noah Weiland and Sharon LaFraniere

Pfizer’s Covid-19 vaccine passed a critical milestone on Thursday when a panel of experts formally recommended that the Food and Drug Administration authorize the vaccine. The agency is likely to do so within days, giving health care workers and nursing home residents first priority to begin receiving the first shots early next week.

The F.D.A.’s vaccine advisory panel, composed of independent scientific experts, infectious disease doctors and statisticians, voted 17 to 4, with one member abstaining, in favor of emergency authorization for people 16 and older. With rare exceptions, the F.D.A. follows the advice of its advisory panels.

With this formal blessing, the nation may finally begin to slow the spread of the virus just as infections and deaths surge, reaching a record of more than 3,000 daily deaths on Wednesday. The F.D.A. is expected to grant an emergency use authorization on Saturday, according to people familiar with the agency’s planning, though they cautioned that last-minute legal or bureaucratic requirements could push the announcement to Sunday or later.

The initial shipment of 6.4 million doses will leave warehouses within 24 hours of being cleared by the F.D.A., according to federal officials. About half of those doses will be sent across the country, and the other half will be reserved for the initial recipients to receive their second dose about three weeks later.

F.D.A. Advisory Panel Gives Green Light to Pfizer Vaccine

FDA Advisory Panel Expected to Approve Pfizer-BioNTech Covid-19 Vaccine

 The Food and Drug Administration and other federal agencies will monitor the use of Covid-19 vaccines long after their release, including the question of how long vaccines will confer immunity, federal officials said at an FDA vaccine panel meeting Thursday.

Nancy Messonnier, a senior official at the U.S. Centers for Disease Control and Prevention specializing in vaccines, said her agency, along with the FDA and the Department of Defense, will conduct “active surveillance” of health care workers and residents of long-term care facilities to gauge the effects of the immunization.

Researchers will make inquiries by text of such trial participants, and “we really need people to sign on to this system to provide us with the best data possible,” she said.

Dr. Messonnier said that such longer-term study will focus on whether children under 16 can benefit from this or other vaccines. So far, the FDA has said, there isn’t enough evidence to prove that a vaccine has a benefit for children. Answering that question could be crucial for reopening most school systems safely.

Her remarks came as a panel of outside advisers convened via videoconference to review the trial data of a Covid-19 vaccine Pfizer Inc. and German partner BioNTech SE. The committee is expected to recommend approval following the daylong hearing.

The committee’s decision will be influential in the FDA decision, expected later this week, whether to authorize the broad use of the vaccine among the American public.

The vaccine has already been shown in clinical research to reduce the rate of symptomatic disease by 95%, and seems certain to get a thumbs-up from both the committee and the FDA. The FDA isn’t required to accept the decision of an advisory panel, but generally does so.

Doran Fink, deputy clinical director of the FDA’s division of vaccines, said further evaluation of the vaccine after its release will be necessary to see if its benefits continue to outweigh its risk, and whether any labeling changes will be required.

Dr. Fink also addressed one major topic that has been in question—whether patients in the Pfizer trial who were randomly assigned to placebo should automatically be switched over and get the vaccine. The FDA’s recommendation to the committee is they shouldn’t.

On behalf of the FDA, he recommended “continuation of blinded, placebo-controlled follow-up in ongoing clinical trials for as long as is feasible.”

Steven Goodman, a Stanford University School of Medicine dean and epidemiologist, in testimony before the panel described that choice as an “ethical dilemma” in which both answers—getting vaccines to placebo patients and developing long-term safety and effectiveness—are right, and neither is unethical. In evaluating the question, Dr. Goodman suggested to the committee “not to use that word at all.”

In answer to questions from the committee, Dr. Fink said the FDA will insist on six months’ follow-up data about safety and side effects when it considers any vaccine for a full approval. The current evaluation by the FDA involves two months of safety data, for an FDA clearance—short of a full approval—called an emergency use authorization.

Arnold Monto, a University of Michigan health researcher who chairs the advisory committee, said the 23-member Vaccines and Related Biological Products Advisory Committee is likely to authorize use of the vaccine.

Dr. Monto said that assessment is based on data released Tuesday showing that the Pfizer vaccine is safe and 95% effective, with adverse reactions rare despite a range of modest side effects such as headaches and fatigue that occur soon after injections.

The panel’s meeting is public and live-streamed. FDA officials hope the discussion will show the care with which the vaccine’s safety has been reviewed—part of a broader effort to convince the public that the vaccine hasn’t been rushed to market for political expediency.

Once the vaccine is approved, officials could face resistance from many Americans unwilling to take it.

Bruce Gellin, president of global immunization at Sabin Vaccine Institute, which promotes vaccine adoption and trains immunization professionals, said the FDA should get credit for being transparent for its review process, including making public its analysis, which other countries don’t necessarily do.

“The FDA puts their cards on the table,” Dr. Gellin said. “They’ve done the analysis and then they put it out there, what they’ve seen and things they’re thinking about.”

The results described in company and FDA analyses earlier this week showed the vaccine’s effectiveness hovered around 95% in all ages and ethnic groups. Those data are especially important, since members of some ethnic groups have shown hesitancy about getting a vaccine.

The findings regarding vaccine effectiveness were also consistent among patients with underlying conditions such as obesity, diabetes, high blood pressure and chronic cardiopulmonary disease.

Serious side effects were extremely rare, though two patients in the U.K. who got the first doses this week had allergic reactions, which were quickly treated. British authorities cleared the vaccine for use last week, as did Canada on Wednesday.

The FDA said patients who got the vaccine during a company clinical study commonly had reactions such as injection-site irritation, fatigue, headache, muscle pain, chills, joint pain and fever. The agency and companies reported on safety data for about 19,000 vaccinated patients in the companies’ research, which included a total of 43,448 patients ages 16 and up.

The committee members, largely composed of doctors such as immunologists, vaccine experts, statisticians and infectious-disease physicians, are expected to focus on side effects as well as data by age, sex and ethnic group.

In the study, a confirmed Covid-19 case was defined as a positive diagnostic test, plus one or more symptoms such as a new or increased cough or shortness of breath, loss of taste or smell, sore throat, diarrhea and vomiting.

Write to Thomas M. Burton at tom.burton@wsj.com and Jared S. Hopkins at jared.hopkins@wsj.com

Microsoft may earn an Affiliate Commission if you purchase something through recommended links in this article.

Thomas M. Burton, Jared S. Hopkins

FDA Advisory Panel Expected to Approve Pfizer-BioNTech Covid-19 Vaccine

11 Minutes of Exercise a Day May Help Counter the Effects of Sitting

 The sweet spot for physical activity and longevity seemed to arrive at about 35 minutes a day of brisk walking or other moderate activities.

By Gretchen Reynolds

Walking for at least 11 minutes a day could lessen the undesirable health consequences of sitting for hours and hours, according to a helpful new study of the ways in which both inactivity and exercise influence how long we live. The study, which relied on objective data from tens of thousands of people about how they spent their days, found that those who were the most sedentary faced a high risk of dying young, but if people got up and moved, they slashed that threat substantially, even if they did not move much.

For most of us, sitting for prolonged periods of time is common, especially now, as we face the dual challenges of Covid-related restrictions and the shortening, chilly days of winter. Recent surveys of people’s behavior since the start of the pandemic indicate that a majority of us are exercising less and sitting more than we were a year ago.

Not surprisingly, there could be long-term health consequences from this physical quietude. Multiple past epidemiological studies show links between sitting and mortality. In general, in these studies, couchbound people are far more likely to die prematurely than active people are.

But how active an active person should be if he or she hopes to mitigate the downsides of sitting has remained unclear. If you sit for eight hours at work, for instance, then stroll for half an hour in the evening — meaning you comply with the standard exercise recommendation of about 30 minutes of exercise most days — is that enough movement to undo most of the health risks of too much sitting?

11 Minutes of Exercise a Day May Help Counter the Effects of Sitting