Wednesday June 19, 2019
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An Experimental Vaccine to Treat Malaria

Scientists hope to get a better grasp on the system these vaccines employ, known as cellular immunity. Harnessing this system could help tackle hepatitis and HIV infection.

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Vaccines
A doctor assists people looking for treatment for malaria at a health center in San Felix, Venezuela. VOA

After decades of disappointment in efforts to develop a malaria vaccine, researchers are starting to see promise in a new approach.

While most vaccines trigger the body’s defenses to produce antibodies against a disease-causing germ, the new approach recruits an entirely different branch of the immune system.

If it works, it could open up a new route to attack other diseases, including hepatitis and possibly HIV, the virus that causes AIDS.

Nearly 450,000 people die of malaria each year, according to the World Health Organization. The parasites that cause the disease are increasingly becoming drug-resistant.

One successful vaccine has been developed so far, but it prevented only about a third of cases in a clinical study.

Experts have decided that’s better than nothing. The vaccine is being piloted in Ghana, Kenya and Malawi.

Vaccine
Defensive cells killed liver cells that were infected with malaria parasites. (VOA)

New angle

Other scientists are trying a different angle of attack.

There are basically two ways to prevent germs from causing infections. “You either prevent them from getting into cells with antibodies, or you kill them inside the cells with T-cells,” said Stephen Hoffman, chief executive officer of Sanaria, a company working on one vaccine.

Most vaccines target the infection by building up antibodies. “If you need to kill them inside the cells with T-cells, we haven’t been overwhelmingly successful,” Hoffman said.

But Sanaria is one group seeing success by targeting malaria parasites inside infected liver cells, the first stop in the complex life cycle of the disease.

One key difference is how the vaccine is delivered. Hoffman’s group tried a typical route: injecting radiation-weakened parasites into patients’ skin or muscle. That didn’t work.

But it did work when injected directly into veins.

Vaccine
A public health worker takes a blood sample from a woman to be tested for malaria in Bo Rai district, Trat province, Thailand. VOA

The weakened parasites traveled to the liver, where they set off an immune reaction. Defensive cells killed liver cells that were infected with malaria parasites.

And the liver’s defenses were ready when faced with the real thing months later.

Most of that early work has been done in mice and macaques. When Hoffman and colleagues did something similar with a handful of human patients, most were protected against infection.

No waiting

Recruiting immune cells in the liver is especially effective because “we don’t need to wait until the immune system figures out that the parasite is in the liver and starts mounting an immune response, which can take days and sometimes weeks,” said Adrian Hill, director of the Jenner Institute at Oxford University.

“By then, the malaria’s gone. It only spends a week in the liver, and then it’s out in your blood causing disease.”

Vaccine
FILE – A worker of the Ministry of Public Health and Population fumigates in the street against mosquito breeding to prevent diseases such as malaria, dengue and Zika in Port-au-Prince, Haiti, Feb. 15, 2016. VOA

Hill’s group just published a study in the journal Science Translational Medicinein which immune cells in the liver were triggered by using a protein from the parasite, rather than the entire organism.

Scientists hope to get a better grasp on the system these vaccines employ, known as cellular immunity. Harnessing this system could help tackle hepatitis and HIV infection.

Also Read: Alcohol Kills More People Than AIDS, Violence Combines: WHO

Drugs can control HIV infection but can’t eliminate it from the body.

“If somebody could get cellular immunity to work really well for vaccination, that would be transformative for a whole range of diseases,” Hill said. “Not just for infectious diseases that we want to prevent, but ones that we want to treat and we can’t treat today.” (VOA)

Next Story

Just Spending 2 Hours a Week in Nature can Work Wonders for Health, Well-Being

It's well known that getting outdoors in nature can be good for people's health

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Nature, Health, Well-Being
People who spend at least 120 minutes a week with nature are significantly more likely to report good health and higher psychological wellbeing than those who do not visit nature at all during an average week. Pixabay

If you are looking for that elusive secret to good health and wellbeing, your search may stop now as a new large-scale study has found that spending just two hours a week in the neighbourhood park may do wonders for your mind and body.

People who spend at least 120 minutes a week with nature are significantly more likely to report good health and higher psychological wellbeing than those who do not visit nature at all during an average week, said the study published in the journal Scientific Reports.

“It’s well known that getting outdoors in nature can be good for people’s health and wellbeing but until now we’ve not been able to say how much is enough,” said lead researcher Mat White of the University of Exeter Medical School in Britain.

“The majority of nature visits in this research took place within just two miles of home so even visiting local urban green spaces seems to be a good thing,” White said.

Nature, Health, Well-Being
If you are looking for that elusive secret to good health and wellbeing, your search may stop now as a new large-scale study has found that spending just two hours a week in the neighbourhood park may do wonders for your mind and body. Pixabay

However, no such benefits were found for people who visited natural settings such as town parks, woodlands, country parks and beaches for less than 120 minutes a week.

The study used data from nearly 20,000 people in England and found that it didn’t matter whether the 120 minutes was achieved in a single visit or over several shorter visits.

It also found that the 120 minute threshold applied to both men and women, to older and younger adults, across different occupational and ethnic groups, among those living in both rich and poor areas, and even among people with long term illnesses or disabilities.

“There are many reasons why spending time in nature may be good for health and wellbeing, including getting perspective on life circumstances, reducing stress, and enjoying quality time with friends and family,” said study co-author Terry Hartig of Uppsala University in Sweden.

Also Read- Countries Approved Projects Worth $1 Billion for Environment, Climate Change

“The current findings offer valuable support to health practitioners in making recommendations about spending time in nature to promote basic health and wellbeing,” Hartig said. (IANS)