LONDON—U.K. researchers plan to start infecting healthy volunteers with tightly controlled doses of the coronavirus in early 2021 in what they called a first-of-its-kind effort to more rapidly gauge the effectiveness of multiple vaccines against Covid-19.
The plans for so-called human-challenge trials target 18- to 30-year-olds who have been free of Covid-19 symptoms and show no other risk factors such as heart disease or diabetes, said the researchers, led by infectious-disease experts at Imperial College London, who are overseeing the effort.
The goal of is to test how effective vaccines are in warding off infection and symptoms and to study in detail how participants’ immune systems respond. Plans are to start at a clinical site at London’s Royal Free Hospital, part of the state-funded National Health Service, and eventually expand the study to other sites nationwide, researchers said.
Scientists around the globe for months have debated whether deliberately infecting healthy people with the virus that causes Covid-19 is too high risk and therefore unethical.
The debate over inoculating humans with live, potent viruses has gone on for centuries. In a now-famous experiment in the late 1700s, British doctor Edward Jenner injected a child with the smallpox virus, then recorded details of the boy’s reaction.
The U.K. researchers said Tuesday that independent ethics and health committees will first have to approve the study before volunteers are enrolled, and they will closely monitor every phase, from participant screening to injection, isolation and follow-up.
Initially, trial subjects will be quarantined and compensated for an expected period of two to 2½ weeks, the group of researchers said. Scientists plan to expose the volunteers initially with the smallest dose possible until they find a level that reliably causes infection. The virus will be injected as droplets through the nose.
That first phase of the study doesn’t involve a vaccine, scientists said. After the researchers better understand infection levels and participant responses, they will integrate vaccines to measure their effectiveness when volunteers encounter the virus.
Backers of challenge trials say they are necessary in the pandemic to expedite approval and fine-tuning of vaccines and for better understanding of the disease. Vaccines normally can take eight to 10 years to develop. Covid-19 has spurred accelerated research and testing of experimental vaccines in a fraction of that time in bids to save lives and jump-start economies. Leading Covid-19 vaccine candidates have progressed into late-stage testing and could be available, if granted emergency authorization, as early as December, companies developing them have said.
Researchers in the planned U.K. challenge trials said they haven’t identified which vaccine candidates they will use, and said the challenge study doesn’t replace conventional vaccine clinical trials, which rely on participants to be naturally exposed to the virus.
During the challenge trials, treatments, which will initially include the antiviral drug remdesivir, will be at the ready and administered most likely before the volunteers even show symptoms, in an effort to limit the risk of severe disease, Dr. Chris Chiu, the study’s lead researcher from Imperial
Scientists have proposed a new therapy for type 2 diabetes. If proven effective, the therapy could help some people discontinue insulin treatment.
Scientists have proposed a new therapy for the treatment of type 2 diabetes, with a proof-of-concept study showing positive initial results. If effective, the therapy may mean that some people can stop taking insulin treatment.
The authors of the research presented their findings at UEG Week Virtual 2020, a conference organized by United European Gastroenterology, a professional nonprofit organization for specialists in digestive health.
According to the National Institute of Diabetes and Digestive and Kidney Diseases, a person may have type 2 diabetes when their blood sugar is too high.
People gain blood sugar, or blood glucose, mainly from the food they eat. Insulin helps cells access this glucose to use as energy. However, for a person with type 2 diabetes, either their body does not make enough insulin or their cells do not respond to insulin correctly.
This then means that the glucose in their blood increases, which can lead to complications of diabetes, such as heart and kidney disease, visual impairment, and loss of sensation in the limbs. The higher the blood glucose over time, the higher the risk of these complications.
According to the Centers for Disease Control and Prevention (CDC), about 1 in 10 adults in the United States have diabetes, and 90–95% of these individuals have type 2 diabetes.
Doctors typically recommend lifestyle changes, such as being more physically active and eating a more healthful diet, to treat type 2 diabetes, as well as medications to manage a person’s blood pressure and blood glucose levels.
Insulin treatment may be necessary if a person is unable to maintain their blood sugar at normal levels. This treatment can take the form of injections, pens, pumps, or inhalers. It encourages the cells in a person’s body to absorb more blood sugar.
However, people’s perception of the side effects of insulin treatment can be quite pronounced. As a result, doctors may be less likely to prescribe insulin, and, when they do, people may not take it regularly.
Consequently, therapies that can avoid these perceived side effects may be valuable in ensuring that people keep up with their prescribed treatment and avoid risking serious health issues.
In this context, the researchers behind the present study used a novel technique that scientists first reported using in humans in 2016. Based on those preliminary results, it seemed promising.
The technique is called duodenal mucosal resurfacing (DMR). The duodenum is the first part of a person’s small intestine. DMR involves lifting the mucosal layer of the duodenal to allow the ablation of the revealed area using heated water — a process that removes the cells in the targeted area.
The researchers who developed the DMR technique were trying to replicate the positive impact that bariatric surgery (gastric bypass) has on blood sugar levels with a less invasive technique.
Studies of how bariatric surgery improves blood sugar control have concluded that there