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COVID-19 may increase risk of Alzheimer’s, Parkinson’s, stroke: study

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A new Danish study found COVID-19 outpatients had a higher risk of being diagnosed with Parkinson’s, Alzheimer’s, stroke and bleeding into the brain when compared with COVID-19 negative patients, but most neurological disorders were not more frequent after COVID-19 than after other respiratory infections, according to a recent study published in Frontiers in Neurology this June.  

“More than two years after the onset of the COVID-19 pandemic, the precise nature and evolution of the effects of COVID-19 on neurological disorders remained uncharacterized,” said lead author Dr. Pardis Zarifkar, member of the Department of Neurology at Rigshospitalet hospital in Copenhagen, Denmark.  

“Previous studies have established an association with neurological syndromes, but until now it is unknown whether COVID-19 also influences the incidence of specific neurological diseases and whether it differs from other respiratory infections.” 

The study, which was recently presented at the 8th European Academy of Neurology Congress, found 43,375 individuals tested positive for COVID-19 while 876,356 individuals tested negative for the disease out of a total of 919,731 participants. 

Small pea-sized human midbrain-like organoids – which are essentially three-dimensional, multicellular, in vitro tissue constructs that mimic the human midbrain – are grown from human stem cells to enable scientists to study how the human brain develops and communicates. A new Danish study found COVID-19 outpatients had a higher risk of being diagnosed with Parkinson’s, Alzheimer’s, stroke and bleeding into the brain when compared with COVID-19 negative patients, but most neurological disorders were not more frequent after COVID-19 than after other respiratory infections, according to a recent study published in Frontiers in Neurology this June.  

Small pea-sized human midbrain-like organoids – which are essentially three-dimensional, multicellular, in vitro tissue constructs that mimic the human midbrain – are grown from human stem cells to enable scientists to study how the human brain develops and communicates. A new Danish study found COVID-19 outpatients had a higher risk of being diagnosed with Parkinson’s, Alzheimer’s, stroke and bleeding into the brain when compared with COVID-19 negative patients, but most neurological disorders were not more frequent after COVID-19 than after other respiratory infections, according to a recent study published in Frontiers in Neurology this June.  
(Hyunsoo Shawn Je, Duke-NUS Medical School)

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The study used electronic health records that covered approximately 50% of Denmark’s population, which has an estimated population of 3 million. 

The study analyzed those who tested positive for COVID-19 and bacterial pneumonia in hospital-based facilities between February 2020 and November 2021, as well as reviewed influenza patients from the corresponding pre-pandemic period between February 2018 and November 2019. 

Out of the 43,375 patients who tested positive for COVID-19, 35,362 were outpatients while 8,013 were hospitalized.  

The researchers found the outpatients who tested positive for COVID-19 had a 3.5 times the risk of being diagnosed with Alzheimer’s disease, 2.6 times increased risk with Parkinson’s disease, 2.7 times increased risk with ischemic stroke and 4.8 times increased risk with intracerebral hemorrhage, which is bleeding in the brain.  

But when the researchers compared the relative risk of neurological disorders with other respiratory illnesses, such as influenza, the increased risk of most neurological diseases was not higher in COVID-19-positive patients compared to those diagnosed with other respiratory illnesses – with one exception.  

Brain disease diagnosis with medical doctor seeing Magnetic Resonance Imaging (MRI) film diagnosing elderly ageing patient neurodegenerative illness problem for neurological medical treatment. But when the researchers compared the relative risk of neurological disorders with other respiratory illnesses, such as influenza, the increased risk of most neurological diseases was not higher in COVID-19-positive patients compared to those diagnosed with other respiratory illnesses -- with one exception.  

Brain disease diagnosis with medical doctor seeing Magnetic Resonance Imaging (MRI) film diagnosing elderly ageing patient neurodegenerative illness problem for neurological medical treatment. But when the researchers compared the relative risk of neurological disorders with other respiratory illnesses, such as influenza, the increased risk of most neurological diseases was not higher in COVID-19-positive patients compared to those diagnosed with other respiratory illnesses — with one exception.  
(iStock)

The researchers found the risk for ischemic stroke increased among COVID-19 hospitalized patients when compared to inpatients with influenza. 

The study was limited because it did not account for potential confounding variables like socioeconomic, lifestyle, pre-existing comorbidities and length of hospitalization. 

Medical illustration of a brain with stroke symptoms. The researchers found the risk for ischemic stroke increased among COVID-19 hospitalized patients when compared to inpatients with influenza. 

Medical illustration of a brain with stroke symptoms. The researchers found the risk for ischemic stroke increased among COVID-19 hospitalized patients when compared to inpatients with influenza. 
(iStock)

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Although the study included a large population, it was only able to review a subset of the country’s absolute number of tested individuals as only COVID-19 tests performed in the hospital facilities are registered in the Danish electronic health record system that the study used to analyze the records. 

“While the risk of ischemic stroke was increased with COVID-19 compared to influenza, reassuringly, most neurological disorders do not appear to be more frequent after COVID-19 than after influenza or community-acquired bacterial pneumonia,” the researchers concluded.  

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“Frequencies of multiple sclerosis, myasthenia gravis, Guillain-Barré syndrome and narcolepsy did not differ after COVID-19, influenza and bacterial pneumonia,” the study added.  

“These findings will help to inform our understanding of the long-term effect of COVID-19 on the body and the role that infections play in neurodegenerative diseases and stroke,” Zarifkar said. 

When Abortion Pills Were Banned in Brazil, Women Turned to Drug Traffickers

Women’s reliance on the black market for access to medication abortions means they may not follow best medical practice. When C., a 24-year-old teacher in Recife, bought misoprostol from a drug dealer last year, she searched Google to figure out how to take it. “Because it was illegal, there was no information about how to take it or what to take,” she said.

Her search found recommendations to insert the tablets in her vagina, as a doctor would if she were in a clinic, but cautioned that traces might be left behind and give her away if she wound up in hospital; instead, she dissolved them under her tongue, a method that also works but less quickly.

C., who asked to be identified only her middle initial out of fear of prosecution, bled for weeks after and wanted to ask her mother, a gynecologist, for advice. But her mother is an anti-abortion activist. Finally, C. said she thought she had miscarried, and her mother took her to see a colleague who performed a dilation-and-curettage under anesthetic.

“When I was having the curettage, I had to keep saying over and over to myself, ‘Don’t say anything, you can’t say anything’ — it was torture,” she said. “Even though I was totally sure that I wanted an abortion, I had no doubts, you still feel like you’ve done something wrong because you can’t talk about it.”

The restriction on misoprostol has complicated regular obstetric care, which uses on the drug for induction of labor, said Dr. Derraik. At the Rio public maternity hospital where she is medical director, a doctor must fill out a request in triplicate for the drug, have it signed by Dr. Derraik, take it to the pharmacy where the supervisor must also sign before taking it out of a locked cabinet, and then the physician must administer the drug with a witness, to ensure it is not diverted for black market sale.

“Not all of these steps are officially required,” Dr. Derraik said. “But hospitals do them because of the intense paranoia around the drug.”

Opposition Leader Matthew Guy pledges $25m revamp for Sandringham Hospital

A $25m refurbishment of a hospital in Melbourne’s leafy Bayside has been promised ahead of the state’s next election.

The multimillion-dollar revamp of a hospital in Melbourne’s leafy Bayside has been promised by the Victorian Opposition in a bid to gain voters in the cashed-up area.

Sandringham Hospital, 20km south of the city, provides maternity services, general surgery and operates a 24/7 emergency department.

However, its facilities have been heavily hampered by a backlog of elective surgeries built up through months of suspensions during Covid lockdowns.

Opposition Leader Matthew Guy said the Liberals’ plan was aimed to bolster services for Melburnians in surrounding suburbs.

“Cutting and closing local hospitals is not the way to recover, rebuild and move forward with confidence,” Mr Guy said.

“This commitment is an important part of our plan to fix Victoria’s healthcare crisis and will help give Sandringham the local health services they deserve.”

It comes after the state government considered cutting the emergency department’s opening hours to 12 a day

Eight short-stay post-operative beds have additionally been cut along with the displacement of five full-time nursing staff.

The general surgical unit has also been disbanded and could result in the loss of seven surgeons from the hospital.

Mr Guy’s plan would cost $25m and modernise wards, refurbish maternity facilities and allow the emergency department to stay open 24 hours a day.

Member for Sandringham Brad Rowswell said the upgrades were needed to provide for the area’s medical needs.

“I was born at Sandy Hospital 36 years ago and the place hasn’t changed much since then,” he said.

“Our plan will support critical health services, upgrade facilities for the future and bring the local community together to ensure the Sandringham Hospital can service the next generation of local residents.”

Surgeons at the hospital earlier this year fought a plan to make it a surgical hub due to fears it would lead to delayed patient treatment and medical job losses.

The scheme is part of the state government’s plan to speed elective surgery up to 125 per cent of pre-pandemic levels if it is re-elected in November to clear the system’s backlog.

This would result in an extra 40,000 operations in 2023 and up to 240,000 each year from 2024.

Originally published as Opposition Leader Matthew Guy pledges $25m revamp for Sandringham Hospital

Blacks and Asians four times more likely to die of Covid

Black people, Asians and Hispanics hospitalised with Covid are four times likely to die compared to their Caucasian counterparts, according to a new international study led by University of Cape Town (UCT) cardiologists. The main predictors of mortality were older age, over 60, male, pre-existing coronary heart disease, diabetes, renal disease, severe Covid infection with higher respiratory rates and requiring ICU admission and oxygen. Patients from low, lower-middle and upper-middle income countries were at significantly greater risk of mortality than high-income countries. Professor Karen Sliwa – one of the principal investigators of the study and director of the Cape Heart…

Repeal of remaining Covid rules on the way?

The President’s Coordinating Council will on Wednesday discuss the possible lifting of remaining pandemic regulations as SA exits fifth wave

The post Repeal of remaining Covid rules on the way? appeared first on The Mail & Guardian.

Some states ban abortion after Supreme Court voids Roe v. Wade

Pro-life demonstrators hold signs in front of the U.S. Supreme Court as they await its decision on the legality of a Republican-backed Louisiana law that imposes restrictions on abortion doctors in Washington, U.S., June 22, 2020.

Kevin Lemarque | Reuters

Several U.S. states immediately banned abortion on Friday in the wake of the Supreme Court’s ruling that overturned Roe v. Wade, dividing the nation between jurisdictions where the procedure is legal and where it is outlawed.

The high court’s decision ended a half-century of constitutionally protected abortion rights, which means that states will now be allowed to regulate the procedure.

At least 13 states have laws on the books that either ban abortion immediately or will do so soon.

Abortion bans in Arkansas, Kentucky, Louisiana, Missouri, Oklahoma, South Dakota, Utah and Alabama went into immediate effect. The laws make performing an abortion a felony punishable by years-long prison sentences. They do not make exceptions for rape or incest. However, women cannot be prosecuted for receiving an abortion under the laws.

Wisconsin has a 19th-Century law on the books banning nearly all abortions, but the state’s Democratic governor and attorney general said they will not enforce it. Doctors in Wisconsin, however, reportedly stopped providing abortions following the Supreme Court’s decision.

On the West Coast, the governors of California, Oregon and Washington vowed to expand access to abortion and protect women who come to their states in need of the procedure.

Read the reactions to Roe v. Wade being overturned

Anyone who performs an abortion in Arkansas, Louisiana and Oklahoma faces 10 years in prison unless the procedure is done to save the life of the pregnant woman. Arkansas and Louisiana also make exceptions for physicians to end ectopic pregnancies or treat miscarriages.

In Missouri, anyone who performs an abortion would face up to a 15-year jail sentence, unless the procedure is done in the case of a medical emergency.

Pro-choice supporters and staff of Planned Parenthood hold a rally outside the Planned Parenthood Reproductive Health Services Center in St. Louis, Missouri, May 31, 2019, the last location in the state performing abortions.

Saul Loeb | AFP | Getty Images

In Kentucky, anyone who performs an abortion would face up to five years in prison. The law makes exceptions to save the life of the pregnant woman or procedures by physicians that result in the unintentional end of a pregnancy. Gov. Andy Beshear, a Democrat, condemned the law as extremist.

Any person who performs an abortion in South Dakota now faces up to two years in prison, unless the procedure is performed to protect the life of the mother.

Idaho, Tennessee and Texas will implement abortion bans in 30 days, according to the text of the laws. Abortion bans in Mississippi, Missouri, North Dakota, Oklahoma, Utah and Wyoming go into effect after the attorney general, governor or certain legislative bodies certify that the Supreme Court has done away with Roe.

On Friday, U.S. Attorney General Merrick Garland said the Department of Justice will protect women who travel from states with bans to receive abortions in states where the procedure is legal.

“Few rights are more central to individual freedom than the right to control one’s own body, Garland said. “The Justice Department will use every tool at our disposal to protect reproductive freedom. And we will not waver from this Department’s founding responsibility to protect the civil rights of all Americans.”

Abortion pill next flashpoint

States banning abortion are also outlawing the use of the abortion pill to end pregnancies. However, women cannot be punished for receiving abortions under the laws, which means many people may turn to online pharmacies based abroad to have pills delivered to their homes.

Boxes of the medication Mifepristone used to induce a medical abortion are prepared for patients at Planned Parenthood health center in Birmingham, Alabama, March 14, 2022.

Evelyn Hockstein | Reuters

The abortion pill, mifepristone, is approved in the U.S. to end pregnancies before the 10th week of pregnancy. The Food and Drug Administration first approved the medication in 2000, but required women to obtain it in person under a program that monitors certain drugs for safety risks. Abortion rights advocates fiercely criticized the FDA requirements, arguing that mifepristone had a long and proven track record as a safe and effective way to end an early pregnancy.

In response to the Covid-19 pandemic last year, the FDA temporarily lifted the requirement that women obtain the pill in person. In December, the agency permanently ended the in-person requirement, which will allow certified pharmacies in the U.S. to fill and send prescriptions by mail.

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Garland said states cannot ban mifepristone based on disagreements with FDA’s judgment that the medication is safe and effective. U.S. Health Secretary Xavier Becerra said his department will use “every lever” to protect access to abortion care including with the pill.

Medication abortion has become increasingly common in the U.S. More than half of abortions in the U.S. are with the pill, according to a survey by the Guttmacher Institute of all known providers in the U.S.

Although the state bans do not punish women who receive abortions, there are cases where people have been reported to authorities for trying to end their pregnancies.

In April, a woman in South Texas was charged with murder after allegedly having a self-induced abortion. The district attorney ultimately dismissed the indictment, saying it is clear that she “cannot and should not be prosecuted for the allegation against her.”

Biden officials to keep private the names of hospitals where patients contracted Covid

“Not knowing what the likelihood of getting transmission in the hospital really impacts an individual’s ability to quote unquote ‘make a personal decision’ on their risk levels,” said Mia Ives-Rublee, a disability rights advocate who has a lung condition that makes her more susceptible to Covid.

Over the four weeks ending June 19, U.S. hospitals reported an average of 1,457 patients per week had caught Covid during their stay, according to a POLITICO analysis of data from the Department of Health and Human Services. That follows a record month in January when more than 3,000 patients each week were infected while in the hospital.

Though the higher numbers have subsided, the risk remains real for a subset of the population with compromised immune systems who must weigh getting check-ups and treatments for potentially serious issues “versus maybe getting Covid and ending up on the ventilator,” Ives-Rublee said.

In a March meeting with the CDC, Ives-Rublee and other patient advocates requested more transparency on hospitals’ transmission, but the conversations went nowhere, she said.

“We are frustrated with the lack of progress that we’ve seen in terms of addressing concerns for folks who are extremely at risk for Covid,” Ives-Rublee said.

Other advocates told POLITICO they intend to keep pressing the administration ahead of what the Centers for Disease Control and Prevention predicts could be another fall surge in Covid cases.

“A majority of voters want HHS to level with us – tell us how much coronavirus is spreading in the particular hospital we go to,” said Matthew Cortland, an immunocompromised disability rights activist who ran a recent poll on the issue for Data for Progress, a left-leaning think tank. “But that transparency is inconvenient for the powerful hospital lobby.”

The American Hospital Association wants facilities’ infection numbers to stay private. “Reporting aggregate data is the most appropriate approach given the very low occurrence of hospital onset COVID-19,” Nancy Foster, an executive with the AHA, said in a statement.

Throughout the pandemic, many hospitals chose not to implement measures that could have dramatically decreased transmission, according to workers, health executives and patients around the country.

Many facilities no longer require masks for visitors or staff, despite CDC recommendations. Even where masks are required, workers and visitors usually don surgical masks, among the least protective ones available, instead of N95s. Hospitals follow CDC guidelines, which allow Covid-positive staff to return while infectious. Industry executives insist their protocols are adequate and that some Covid transmission is inevitable; the AHA says hospitals’ measures are generally safe.

U.S. health officials have debated the merits of identifying hospitals’ infections since the Trump administration began collecting the information in 2020, according to three current and former officials who were granted anonymity to speak candidly about internal deliberations.

The figures only include patients who test positive after a minimum hospital stay of 14 days to ensure a patient didn’t contract the virus before admission. The government’s tallies are likely less than the total because hospitals don’t report people who test positive after being discharged.

Trump-era officials decided to keep hospitals’ names private, fearing that outing them might discourage people from seeking health care, according to two former health officials, one of whom worked in the Trump and Biden administrations. Also, a Trump HHS spokesperson confirmed the thinking.

But more than two years into the pandemic, with the availability of vaccines and treatments, Biden officials no longer worry that most patients are avoiding care, according to one of the people involved in more recent discussions. Some U.S. health officials want the same kind of transparency that exists for other hospital-acquired infections, they say. For years, the U.S. government has collected patient infection rates for various pathogens and published scores for each hospital on a website for patients.

Yet the CDC and Office of the Assistant Secretary Preparedness and Response, the two agencies that could make the data public, have declined to release it. POLITICO filed freedom of information requests in April but federal officials have not yet provided the records.

A HHS spokesperson said in a statement the agency wouldn’t release the names for “privacy concerns” but declined to specify what the privacy concerns were.

One concern held by some federal health officials is that the disclosure could embarrass hospitals and lead them to stop reporting their information, according to one U.S. health official who has discussed the matter with the CDC and CMS. But, that concern isn’t universally held.

Some CDC officials have argued internally that the information — as hospitals currently provide it — is not a good measure of risk, according to two CDC officials who have reviewed the data, who were granted anonymity to speak about internal debates. That’s because facilities report snapshots each day of the number of patients who currently have hospital-acquired Covid, meaning some patients are counted again in the following days as they remain in the facility.

The CDC didn’t respond to comment requests.

Allan James Vestal contributed to this report.

Monkeypox mutating more than previously thought, researchers say

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There are now more than 200 monkeypox and orthopoxvirus cases confirmed in the U.S., and experts are warning that the virus is mutating more that previously believed.

In a study published Thursday in the journal Nature Medicine, a group of Portuguese researchers found that there were an average of 50 mutations in samples from 2022 compared with those from 2018 and 2019. 

They wrote that the mutation rate – discovered after looking at 15 monekypox virus sequences – may suggest a case of “accelerated evolution.”

Genetic analysis from earlier this month previously suggested that there are two distinct strains in the U.S., raising the possibility that the virus had been circulating for a while.

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Test tube labeled "Monkeypox virus positive" is seen in this illustration taken May 22, 2022. 

Test tube labeled “Monkeypox virus positive” is seen in this illustration taken May 22, 2022. 
(REUTERS/Dado Ruvic/Illustration/File Photo/File Photo)

Current data from the Centers for Disease Control and Prevention (CDC) shows the majority of cases in California, New York and Illinois. 

Kentucky health officials announced the state’s first probable case on Friday. 

However, scientists have noted that the outbreak is potentially much larger than the current case count.

The CDC confirmed that there has been evidence of local transmission of monkeypox, in addition to the cases where the infected had traveled abroad. 

This 2003 electron microscope image made available by the Centers for Disease Control and Prevention shows mature, oval-shaped monkeypox virions, left, and spherical immature virions, right, obtained from a sample of human skin associated with the 2003 prairie dog outbreak. 

This 2003 electron microscope image made available by the Centers for Disease Control and Prevention shows mature, oval-shaped monkeypox virions, left, and spherical immature virions, right, obtained from a sample of human skin associated with the 2003 prairie dog outbreak. 
(Cynthia S. Goldsmith, Russell Regner/CDC via AP)

This weekend is New York City’s annual Pride weekend, and some residents told The New York Times they were taking monekypox virus transmission risk into account. 

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On Thursday health officials in the Big Apple expanded access to a monkeypox vaccine. 

However, citing high demand, the city-run Chelsea Sexual Health Clinic – the only facility in New York administering the vaccine – said it would no longer be able to accommodate walk-ins almost immediately and that all appointments had been filled through next Monday.

The Biden administration has begun to ship monkeypox virus tests to commercial laboratories, which the Department of Health and Human Services (HHS) said would “dramatically expand testing capacity nationwide.” 

A section of skin tissue, harvested from a lesion on the skin of a monkey, that had been infected with monkeypox virus, is seen at 50X magnification on day four of rash development in 1968. 

A section of skin tissue, harvested from a lesion on the skin of a monkey, that had been infected with monkeypox virus, is seen at 50X magnification on day four of rash development in 1968. 
(CDC/Handout via REUTERS.)

Although the majority of new monkeypox cases have been seen in gay or bisexual men, experts caution that anyone is at potential risk. 

People normally become infected with the monkeypox virus through contact with the skin lesions or bodily fluids of infected animals or humans or through contact with materials contaminated with the virus.

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Monkeypox, which is related to smallpox, has milder symptoms. 

Some symptoms of monkeypox include fever, chills, rash and aches, before lesions develop. 

F.D.A. Aims to Cut Down on Smoking by Slashing Nicotine Levels in Cigarettes

The Food and Drug Administration is planning to require tobacco companies to slash the amount of nicotine in traditional cigarettes to make them less addictive and reduce the toll of smoking that claims 480,000 lives each year.

The proposal, which could take years to go into effect, would put the United States at the forefront of global antismoking efforts. Only one other nation, New Zealand, has advanced such a plan.

The headwinds are fierce. Tobacco companies have already indicated that any plan with significant reductions in nicotine would violate the law. And some conservative lawmakers might consider such a policy another example of government overreach, ammunition that could spill over into the midterm elections.

Few specifics were released on Tuesday, but according to a notice published on a U.S. government website, a proposed rule would be issued in May 2023 seeking public comment on establishing a maximum nicotine level in cigarettes and other products. “Because tobacco-related harms primarily result from addiction to products that repeatedly expose users to toxins, F.D.A. would take this action to reduce addictiveness to certain tobacco products, thus giving addicted users a greater ability to quit,” the notice said.

The F.D.A. declined to provide further details. But in a statement posted on its website, Dr. Robert M. Califf, the agency’s commissioner, said: “Lowering nicotine levels to minimally addictive or non-addictive levels would decrease the likelihood that future generations of young people become addicted to cigarettes and help more currently addicted smokers to quit.”

Similar plans have been discussed to lessen Americans’ addiction to tobacco products that coat the lungs with tar, release 7,000 chemicals and lead to cancer, heart disease and lung disease. Nicotine is also available in e-cigarettes, chews, patches and lozenges, but this proposal would not affect those products.

“This one rule could have the greatest impact on public health in the history of public health,” said Mitch Zeller, the recently retired F.D.A. tobacco center director. “That’s the scope and the magnitude we’re talking about here because tobacco use remains the leading cause of preventable disease and death.”

About 1,300 people die prematurely each day of smoking-related causes, according to the Centers for Disease Control and Prevention.

The obstacles to such a plan, though, are immense and could take years to overcome. Some plans that have been floated would require a 95 percent reduction in the amount of nicotine in cigarettes. Experts say that could toss U.S. smokers, an estimated 30 million people, into a state of nicotine withdrawal, which involves agitation, difficulty focusing and irritability and send others in search of alternatives such as e-cigarettes. Those deliver nicotine without most of the chemicals found in combustible cigarettes.

Experts said that determined smokers might seek to buy high-nicotine cigarettes on illegal markets or across the borders in Mexico and Canada.

The F.D.A. would likely have to overcome opposition from the tobacco industry, which has already begun pointing out the reasons the agency cannot upend an $80 billion market. Legal challenges could take years to resolve, and the agency may give the industry five or more years to make the changes.

The effort to lower nicotine levels follows a proposed rule announced in April that would ban menthol-flavored cigarettes, which are heavily favored by Black smokers. That proposal was also hailed as a potential landmark advance for public health and has already drawn tens of thousands of public comments. The F.D.A. is bound to review and address those comments before finalizing the rule.

Other major tobacco initiatives outlined in the landmark 2009 Tobacco Control Act have been slow to take shape. A lawsuit delayed a requirement for tobacco companies to put graphic warnings on cigarette packs. And the agency recently said it would take up to another year to finalize key decisions on which e-cigarettes might remain on the market.

A statement from the tobacco company Altria, the maker of Marlboro, offered a preview of arguments that opponents are expected to make against any rule that drastically slashes nicotine levels. “The focus should be less on taking products away from adult smokers and more on providing them a robust marketplace of reduced harm FDA-authorized smoke-free products,” the company said in a statement on Tuesday. “Today marks the start of a long-term process, which must be science-based and account for potentially serious unintended consequences.”

RAI Services, the parent company of RJ Reynolds, declined to comment on the announcement, but said: “Our belief is that tobacco harm reduction is the best way forward to reduce the health impacts of smoking.”

“Both an express and a de facto ban would have precisely the same effect — both would eviscerate Congress’s expressly stated purpose ‘to permit the sale of tobacco products to adults,’” according to a letter in 2018 from RAI Services to the F.D.A. about an earlier proposal.

Five years ago, Dr. Scott Gottlieb, the agency’s commissioner at the time, released a plan to cut nicotine levels in cigarettes to a minimally or non-addictive level. The proposal took shape in 2017 but did not lead to a formal rule during the Trump administration.

Among the 8,000 comments that poured in on that proposal, opposition emerged from retailers, wholesalers and tobacco companies. The Florida Association of Wholesale Distribution, a trade group, said it could result in “new demand for black market products, and result in increased trafficking, crime and other illegal activity.”

In 2018, RAI Services said that the F.D.A. had no evidence that the plan to cut nicotine levels would improve public health. The agency “would need to give tobacco manufacturers decades to comply” and figure out how to consistently grow low-nicotine tobacco, RAI said in the letter to the F.D.A. The Tobacco control law of 2009 gave the F.D.A. broad powers to regulate tobacco products with standards “appropriate for the protection of the public health,” although the law specifically outlawed a ban on cigarettes or the reduction of nicotine levels to zero.

Low-nicotine cigarettes are already available to consumers, albeit in a limited fashion. This spring, a New York plant biotech company, 22nd Century Group, began selling a reduced-nicotine cigarette that took 15 years and tens of millions of dollars to develop through the genetic manipulation of the tobacco plant. The company’s brand, VLN, contains 5 percent of the nicotine level of conventional cigarettes, according to James Mish, the company’s chief executive.

“This is not some far-off technology,” he said.

To earn its F.D.A. designation as a “reduced-risk” tobacco product, VLN was subjected to a raft of testing and clinical trials by regulators.

For now, the company is selling VLN at Circle K convenience stores in Chicago as part of a pilot program. Mr. Mish described sales as “modest” — retail prices are similar to premium brands like Marlboro Gold — but he said the F.D.A. proposal would most likely accelerate plans for a national rollout in the coming months.

Dr. Neal Benowitz, a professor of medicine at the University of California, San Francisco, who studies tobacco use and cessation, first proposed the idea of paring the nicotine out of cigarettes in 1994.

He said one key concern was whether smokers would puff harder, hold in smoke for a longer time or smoke more cigarettes to compensate for the lower nicotine level. After several studies, researchers discovered that the cigarette that prevented those behaviors was the lowest-nicotine version, one with about 95 percent less of the addictive chemical.

Dorothy K. Hatsukami, a professor of psychiatry at the University of Minnesota who studies the relationship between nicotine and smoking behavior, said a growing body of evidence suggested that a rapid and significant reduction of nicotine in cigarettes would provide greater public health benefits than the gradualist approach that some scientists had been promoting.

A 2018 study led by Dr. Hatsukami that followed the habits of 1,250 smokers found that participants who had been randomly assigned cigarettes with ultralow nicotine smoked less and exhibited fewer signs of dependency than those who had been given cigarettes with nicotine levels that were gradually reduced over the course of 20 weeks.

There were, however, downsides to slashing nicotine in one fell swoop: Participants dropped out of the study more frequently than those in the gradualist group, and they experienced more intense nicotine withdrawal. Some secretly turned to their regular, full-nicotine brands.

“The bottom line is we’ve known for decades that nicotine is what makes cigarettes so addictive, so if you reduce the nicotine, you make the experience of smoking less satisfying, and you increase the likelihood that people will try to quit,” she said.

A recent study offers a cautionary tale, though, on the degree of public health benefit that lawmakers can expect from tobacco-control policy. While there is no other nation to look to for experience with a low-nicotine cigarette mandate, there is for the menthol flavor ban.

Alex Liber, an assistant professor in the oncology department of Georgetown University’s School of Medicine who studies tobacco control policy, examined Poland’s experience with a menthol cigarette ban instituted in 2020.

The study he and others wrote found the ban did not lead to a decrease in overall cigarette sales, Mr. Liber said, probably because tobacco companies cut cigarette prices and also began selling flavor-infusion cards (for about a quarter each) that users can put in their cigarette pack to add back the flavor. (Some experts say any move to sell flavor-infusion cards in the U.S. would likely be illegal.)

“They know how to sell and make money and they will make more and more as long as they have wiggle room,” he said. “I just expect nothing less.”

Zolan Kanno-Youngs contributed reporting from Washington.