HEALTH

Weekender

Do masks offer real protection from viruses?

PEOPLE around the world are buying up protective face masks in hopes of keeping the new virus from China at bay.
Some companies have required them for employees. Schools in South Korea have told parents to equip their children with masks and hand sanitiser when they return from winter vacation.
But do the masks work? It depends.
All viruses are small enough to get through a typical strap-on medical mask, but the germs don’t generally spread through the air one at a time, said Dr Mark Denison of Vanderbilt University Medical Center in Nashville, United States, who studies SARS and MERS, the same family as the novel coronavirus.

Masks can prevent the wearer from picking up germs left on surfaces by someone who is sick. – The Star

Instead, viruses ride from person to person on droplets from a sneeze or cough. Those droplets land on hands and other surfaces, where they are touched by others, who then touch their own eyes, noses or mouths.
Masks can block large droplets from a sneeze or cough. That means they have some value, Dr Denison said.
Also, someone in a mask can’t touch their own nose and mouth. That can prevent the wearer from picking up germs left on surfaces by someone who is sick, he said.
Masks are “a very sensible precaution” while scientists work to study exactly how the new virus is transmitted, said University of Oxford researcher Trudie Lang.
However, none of this is based on rigorous research. Nobody has compared groups of masked and unmasked people by exposing them to the new germ, Dr Denison said.
A 2017 review of studies in health care workers suggested masks offer some protection against Sars, but the authors noted “existing evidence is sparse and findings are inconsistent.”
The best way to avoid getting sick from the new virus is to wash your hands with soap and water. If soap and water aren’t available, use an alcohol-based hand sanitiser. That’s the same advice for avoiding regular cold and flu viruses.
The Centers for Disease Control and Prevention (CDC) recommends masks for people being evaluated for the new virus, people confirmed to have it, household members and caregivers. Airline crew should offer a face mask to a sick traveller, it said.
Healthcare workers treating patients with the new virus are advised by the CDC to take additional precautions such as goggles or face shields.
Masks have been commonly used in some countries when wearers are sick, fighting allergies or on days when air pollution is bad. The new virus has fueled demand for them around the world.
In Taiwan, where the holiday is over, factories are up and running. Premier Su Tseng-chang said the government had already distributed 23 million masks and that Taiwan will be able to produce four million more a day.
A mask factory in Shanghai has gone into overdrive despite the holiday.
“We are now working 24 hours, two shifts a day, 12 hours shift,” said Liao Huolin, president of the mask company.
“We violated labour law, but the workers understand.”– AP


HIV vaccine hopes dashed

HOPES have been dashed an experimental vaccine could protect people against HIV, the virus that causes Aids.
The National Institutes of Health has stopped its HVTN 702 trial, of more than 5,000 people in South Africa, as it found the jab did not prevent HIV.
Experts expressed “deep disappointment” but added the search for a preventive HIV vaccine must continue.
Such vaccines do not contain HIV and therefore do not pose any danger of giving HIV to an individual.

What was the vaccine?
The jab was a new version of the first HIV-vaccine candidate shown to provide some protection against the virus – in the RV144 clinical trial, in Thailand.
There are many different strains of HIV and the vaccine had been adapted to the subtype most common in South Africa, which has one of the highest HIV rates in the world.
There were great hopes that the vaccine would work and it could then be adapted to cover other strains of HIV circulating in other parts of the world.

What happened in the trial?
Volunteers were randomly assigned to receive either the vaccine or placebo injections.
And preliminary data showed:

  • 129 HIV infections among the vaccine recipients
  • 123 HIV infections among those given the dummy jab

Dr Anthony Fauci, from the NIH, said: “An HIV vaccine is essential to end the global pandemic and we hoped this vaccine candidate would work. Regrettably, it does not.”
“Research continues on other approaches to a safe and effective HIV vaccine, which I still believe can be achieved.”
Linda-Gail Bekker from the International Aids Society said: “Whilst this is a significant setback for the field, we need to continue the quest for a preventive vaccine.”
There is still hope other HIV vaccines in development may work.

How can HIV be stopped?
A drug treatment called pre-exposure prophylaxis (Prep) is effective at preventing HIV infection but, unlike a vaccine, it needs to be taken regularly, even daily.
In countries where such treatments may not be available, the only effective prevention remains using condoms during sexual intercourse – or abstinence.
Recent breakthroughs in anti-retroviral treatments have improved the lifespan of people with HIV.
Debbie Laycock, Head of Policy at Terrence Higgins Trust said: “Through regular testing, condoms, Prep and effective treatment which means people living with HIV can’t pass on the virus – we now have a once-in-a-generation opportunity to end the HIV epidemic. It’s vital we seize this.”– BBC