The prevalence of obesity in the United States threatens the effectiveness of the COVID-19 vaccine | National/World

For a world with a coronavirus, salvation depends on a vaccine.

But in the United States, where more than 5 million people have been infected and more than 161,000 have died, the promise of the vaccine has been hampered by COVID-19: the nasty epidemic that has long been obese.

Scientists have found that vaccines designed to protect the public from influenza, hepatitis B, tetanus, and rabies are less effective in obese adults and more susceptible to infections and illness than the general population. I know. Obesity researchers have little reason to believe that the COVID-19 vaccine is quite different.

“Will we get a COVID vaccine for obesity next year?” said Raz Sheikh, associate professor of nutrition at the University of North Carolina at Chapel Hill.

“Does it still work in obesity? Our prediction is no.”

More than 107 million American adults are obese, and weak immunity with coronavirus vaccines can reduce their ability to return to work safely, care for their families, and resume daily life. There is.

In March, still early in the global pandemic, a little noteworthy study from China found that heavy Chinese patients with COVID-19 were more likely to die than lean patients. It has been suggested that a dangerous future awaits the most populous United States worldwide.

And that future has arrived.

As an intensive care unit in New York, New Jersey, and elsewhere filled with patients, the Federal Centers for Disease Control and Prevention has a Body Mass Index of 40 or more (known as morbid obesity or about 100 pounds overweight) The group at the highest risk of obese people becoming severely ill with COVID-19. About 9% of American adults belong to that category.

As weeks went by and the focus was on a clearer picture of those in the hospital, the federal health authorities expanded the warning to include people with a body mass index of 30 and above. This has significantly increased the ranks of people considered vulnerable to the most severe cases of infection, to 42.4% of American adults.

Obesity has long been known to be an important risk factor for death from cardiovascular disease and cancer. However, scientists in the emerging field of immune metabolism have also found that obesity also interferes with the body’s immune response, increasing the risk of obese people being infected by pathogens such as influenza and the novel coronavirus. I will. In the case of influenza, obesity is emerging as a factor that makes it more difficult to vaccinate adults against the infection. The question is whether it applies to COVID-19.

A healthy immune system turns inflammation on or off as needed, attracts white blood cells, and pumps proteins to fight infection. The vaccine uses that inflammatory response. However, blood tests have shown that obese people and those with associated metabolic risk factors, such as high blood pressure and elevated blood sugar levels, experience a chronic mild inflammatory condition. The inflammation continues to turn on.

Adipose tissue, or fat-abdomen, liver, and other organs are not inactive. It contains specialized cells that send out molecules like the hormone leptin, which scientists suspect cause this chronic inflammatory condition. The exact biological mechanisms are still under investigation, but chronic inflammation appears to interfere with the immune response to the vaccine, and probably even after vaccination obese people still have preventable illnesses.

Effective vaccines fuel controlled burns in the body and burn a truly never-before simulated invasion into cell memory.

Evidence that obese people respond insensitively to common vaccines suggests that obese hospital employees who received the hepatitis B vaccine had protections not observed in non-obese employees after 11 months. It was first observed in 1985, which showed a significant reduction. The finding was reproduced in a follow-up study using a long needle to confirm that the vaccine was injected into muscle rather than fat.

Researchers found similar problems with the hepatitis A vaccine, and other studies found a significant reduction in tetanus in obese individuals and antibody protection induced by the rabies vaccine.

“Obesity is a serious global problem, and the suboptimal vaccine-induced immune response observed in the obese population cannot be ignored,” said the Mayo Clinic vaccine research group in a 2015 study published in Vaccine. Acknowledged by researchers.

It is also known that the vaccine is less effective in the elderly, so people over the age of 65 receive a once-a-year flu vaccine that contains much more influenza antigens, increasing their immune response.

In contrast, the reduced protection of the obese population in both adults and children has been largely ignored.

“I’m not completely sure why the vaccine’s efficacy in this population is not well-reported,” said Katherine Andersen, an associate professor of biology who studies obesity and metabolic disorders at Fairfield University. It was “It’s a missed opportunity for greater public health intervention.”

In 2017, scientists at UNC Chapel Hill provided important clues about the limitations of the influenza vaccine. A paper published in the International Journal of Obesity first showed that vaccinated obese adults could be twice as likely as healthy-weight adults to develop influenza or flu-like illness.

Oddly enough, they found that obese adults produced protective levels of antibodies to the influenza vaccine, but they were still unresponsive.

“It was a mystery,” said Chad Petit, an influenza virologist at the University of Alabama.

One hypothesis is that obesity may cause metabolic dysregulation of T cells, the white blood cells that are important for the immune response, Petit said. “It’s not insurmountable,” said Petit, who is studying COVID-19 in obese patients. “We can design better vaccines that might overcome this discrepancy.”

(Editor: The story can end here)

Historically, people with a high BMI have been excluded from drug trials because they frequently have associated chronic illnesses that can mask results. Ongoing clinical trials to test the safety and efficacy of coronavirus vaccines do not include a BMI exclusion and include people with obesity, said Dr. Larry Corey of the Fred Hutchinson Cancer Research Center, said Institute.

The trial coordinator does not specifically focus on obesity as a potential complication, but participants’ BMIs will be documented and outcomes assessed, Corley said.

Dr. Timothy Garvey, endocrinologist and director of diabetes research at the University of Alabama, emphasized that it is safer for obese people to be vaccinated, despite a lengthy question.

“The flu vaccine works for patients who are still obese, but not as well,” Garvey said. “We still want them to be vaccinated.”

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(Kaiser Health News (KHN) is a national health policy news service. This is an editorial independent program of the Henry J. Kaiser Family Foundation, which is not affiliated with Kaiser Permanente.)

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(C) 2020 Kaiser Health News

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