Carbohydrates may be key to better malaria vaccine: study

Agencies
September 17, 2017

Melbourne, Sept 17: Scientists have for the first time found that carbohydrates on the surface of malaria parasites play a critical role in malaria's ability to infect mosquito and human hosts.

The discovery may help improve the only vaccine approved to protect people against Plasmodium falciparum malaria - the most deadly form of the disease, researchers said.

The study found that the malaria parasite 'tags' its proteins with carbohydrates in order to stabilise and transport them, and this process was crucial to completing the parasite's lifecycle.

"We found that the parasite's ability to 'tag' key proteins with carbohydrates is important for two stages of the malaria lifecycle," said Justin Boddey, from Walter and Eliza Hall Institute in Australia.

"It is critical for the the earliest stages of human infection, when the parasite migrates through the body and invades in the liver, and later when it is transmitted back to the mosquito from an infected human, enabling the parasite to be spread between people," said Boddey, who led the study published in the journal Nature Communications.

Interfering with the parasite's ability to attach these carbohydrates to its proteins hinders liver infection and transmission to the mosquito, and weakens the parasite to the point that it cannot survive in the host, researchers said.

Malaria infects over 200 million people worldwide each year and kills around 650,000 people, predominantly pregnant women and children.

Efforts to eradicate malaria require the development of new therapeutics, particularly an effective malaria vaccine.

The first malaria vaccine approved for human use - RTS,S/AS01 - was approved by European regulators in July 2015 but has not been as successful as hoped, with marginal efficacy that wanes over time, researchers said.

"The protein used in the RTS,S vaccine mimics one of the proteins we have been studying on the surface of the malaria parasite that is readily recognised by the immune system," said Ethan Goddard-Borger from Walter and Eliza Hall Institute.

"With this study, we have shown that the parasite protein is tagged with carbohydrates, making it slightly different to the vaccine, so the antibodies produced may not be optimal for recognising target parasites," Goddard-Borger said.

He said there were many documented cases where attaching carbohydrates to a protein improved its efficacy as a vaccine.

"It may be that a version of RTS,S with added carbohydrates will perform better than the current vaccine," Goddard-Borger said.

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Agencies
July 30,2020

New York, Jul 30: Can the coronavirus spread through the air? Yes, it's possible.

The World Health Organisation recently acknowledged the possibility that Covid-19 might be spread in the air under certain conditions.

Recent Covid-19 outbreaks in crowded indoor settings — restaurants, nightclubs and choir practices — suggest the virus can hang around in the air long enough to potentially infect others if social distancing measures are not strictly enforced.

Experts say the lack of ventilation in these situations is thought to have contributed to spread, and might have allowed the virus to linger in the air longer than normal.

In a report published in May, researchers found that talking produced respiratory droplets that could remain in the air in a closed environment for about eight to 14 minutes.

The WHO says those most at risk from airborne spread are doctors and nurses who perform specialized procedures such as inserting a breathing tube or putting patients on a ventilator.

Medical authorities recommend the use of protective masks and other equipment when doing such procedures.

Scientists maintain it's far less risky to be outside than indoors because virus droplets disperse in the fresh air, reducing the chances of Covid-19 transmission.

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Agencies
July 15,2020

The first COVID-19 vaccine tested in the US revved up people's immune systems just the way scientists had hoped, researchers reported Tuesday -- as the shots are poised to begin key final testing.

No matter how you slice this, this is good news, Dr. Anthony Fauci, the U.S. government's top infectious disease expert, told The Associated Press.

The experimental vaccine, developed by Fauci's colleagues at the National Institutes of Health and Moderna Inc., will start its most important step around July 27: A 30,000-person study to prove if the shots really are strong enough to protect against the coronavirus.

But Tuesday, researchers reported anxiously awaited findings from the first 45 volunteers who rolled up their sleeves back in March. Sure enough, the vaccine provided a hoped-for immune boost.

Those early volunteers developed what are called neutralizing antibodies in their bloodstream -- molecules key to blocking infection -- at levels comparable to those found in people who survived COVID-19, the research team reported in the New England Journal of Medicine.

This is an essential building block that is needed to move forward with the trials that could actually determine whether the vaccine does protect against infection, said Dr. Lisa Jackson of the Kaiser Permanente Washington Research Institute in Seattle, who led the study.

There's no guarantee but the government hopes to have results around the end of the year -- record-setting speed for developing a vaccine.

The vaccine requires two doses, a month apart.

There were no serious side effects. But more than half the study participants reported flu-like reactions to the shots that aren't uncommon with other vaccines -- fatigue, headache, chills, fever and pain at the injection site. For three participants given the highest dose, those reactions were more severe; that dose isn't being pursued.

Some of those reactions are similar to coronavirus symptoms but they're temporary, lasting about a day and occur right after vaccination, researchers noted.

Small price to pay for protection against COVID, said Dr. William Schaffner of Vanderbilt University Medical Center, a vaccine expert who wasn't involved with the study.

He called the early results a good first step, and is optimistic that final testing could deliver answers about whether it's really safe and effective by the beginning of next year.

It would be wonderful. But that assumes everything's working right on schedule, Schaffner cautioned.

Moderna's share price jumped nearly 15 percent in trading after US markets closed. Shares of the company, based in Cambridge, Massachusetts, have nearly quadrupled this year.

Tuesday's results only included younger adults. The first-step testing later was expanded to include dozens of older adults, the age group most at risk from COVID-19.

Those results aren't public yet but regulators are evaluating them. Fauci said final testing will include older adults, as well as people with chronic health conditions that make them more vulnerable to the virus and Black and Latino populations likewise affected.

Nearly two dozen possible COVID-19 vaccines are in various stages of testing around the world. Candidates from China and Britain's Oxford University also are entering final testing stages.

The 30,000-person study will mark the world's largest study of a potential COVID-19 vaccine so far. And the NIH-developed shot isn't the only one set for such massive U.S. testing, crucial to spot rare side effects. The government plans similar large studies of the Oxford candidate and another by Johnson & Johnson; separately, Pfizer Inc. is planning its own huge study.

Already, people can start signing up to volunteer for the different studies.

People think this is a race for one winner. Me, I'm cheering every one of them on, said Fauci, who directs NIH's National Institute of Allergy and Infectious Diseases.

We need multiple vaccines. We need vaccines for the world, not only for our own country. Around the world, governments are investing in stockpiles of hundreds of millions of doses of the different candidates, in hopes of speedily starting inoculations if any are proven to work.

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News Network
July 10,2020

Toronto, Jul 10: Pasteurising breast milk at 62.5 degrees Celsius for 30 minutes inactivates the SARS-CoV-2 virus that causes Covid-19, making it safe for consumption by babies, a study claims.

According to the research published in the Canadian Medical Association Journal, current advice for women with Covid-19 is to continue to breastfeed their own infants.

In Canada, it is standard care to provide pasteurised breast milk to very-low-birth-weight babies in hospital until their own mother's milk supply is adequate, the researchers said.

"In the event that a woman who is Covid-19-positive donates human milk that contains SARS-CoV-2, whether by transmission through the mammary gland or by contamination through respiratory droplets, skin, breast pumps and milk containers, this method of pasteurisation renders milk safe for consumption," said Sharon Unger, a professor at the University of Toronto in Canada.

The Holder method, a technique used to pasteurise milk in all Canadian milk banks at 62.5 degrees Celsius for 30 minutes, is effective at neutralising viruses such as HIV, hepatitis and others that are known to be transmitted through human milk, the researchers said.

In the latest study, the researchers spiked human breast milk with a viral load of SARS-CoV-2 and tested samples that either sat at room temperature for 30 minutes or were warmed to 62.5 degrees Celsius for 30 minutes.

They then measured for active virus, finding that the virus in the pasteurised milk was inactivated after heating.

More than 650 human breast milk banks around the world use the Holder method to ensure a safe supply of milk for vulnerable infants, the researchers said.

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