Staggering Results Show HIV-Transmission Reduced 100% with Twice-Yearly Lenacapavir Injection

A 2-stage trial testing a new and acclaimed HIV-prevention drug has shown almost unthinkable results of no new infections among a sample size of 3,200 participants.

Called PURPOSE 1, the aim of the first trial was testing a subcutaneous injection of the drug Lenacapavir given twice a year to people in a high-HIV-incidence country, which in this case was Uganda or South Africa.

The results were nothing short of extraordinary—100% efficacy, not a single young woman contracted HIV.

This was followed up by PURPOSE 2, which expanded the geographical area significantly to more countries on more continents, and expanded the pool of individuals from beyond just young women to men—and to those of all ages. 5,000 participants took part.

The result was the same: 99.9% reduction in infection rates.

Both were considered phase 3 clinical trials, and were conducted in a randomized, double-blinded protocol, but were not tested against a placebo. Instead, the Lenacapavir injections were compared to the current standard of HIV prevention—a pill called Truvada or Descovy taken daily.

These both were also found to prevent HIV transmission by 99.9% during development, but must be taken every day to achieve this level of protection. As anyone who’s tried to stick to a once-a-day pill regime long-term will agree, it’s not an easy thing to maintain month after month.

By contrast, the twice-yearly injections are much easier to adhere to, and they also come with the added benefit of removing the social stigma of being seen taking a daily pill and therefore at risk of HIV transmission. This can be particularly alleviating in high-HIV-prevalent countries where male homosexuality is illegal, such as Uganda.

Indeed the superiority of a twice-yearly injection was so clear that both PURPOSE trials were halted early over ethical reasons. A 52-week follow-up screened for HIV developments.

Lenacapavir was named by Science Magazine as the Breakthrough of the Year in 2024, and was approved by the FDA for use in humans under the brand name Yeztugo.

It works to break down the HIVs capsid shell by binding to an “highly conserved” protein on the exterior. That means that no matter how many times or into what form the virus mutates, the exterior shell protein remains—presenting the perfect target for the drug.

In layman’s terms, the drug then works through the protein to disrupt the capsid shell, which the virus ‘takes down’ and ‘builds up’ several times during its lifecycle with perfect geometric precision. The disruption prevents the virus from completing its life cycle.

Initial R&D, regulation compliance, and proof of efficacy and safety requirements mean that producing Lenacapavir has cost its developer, Gilead Sciences, an undisclosed total cost that would be reasonable to estimate at well over a billion dollars based on normal pharma development costs.Gilead has nevertheless committed to providing the drug at cost in certain low-income regions and has licensed generic manufacturers to produce it for approximately $40 per year in 120 low and middle-income countries starting in 2027 Staggering Results Show HIV-Transmission Reduced 100% with Twice-Yearly Lenacapavir Injection

Read More........→July 17, 2026

Curious Kids: can spiders swim?

Leanda Denise Mason, Edith Cowan University

Can spiders swim?

Waubra Preschool students, Victoria, Australia

What a great question!

Most spiders don’t swim by choice. But they sure can survive in water when they need to. From floating like a boat, to paddling like a rower, to carrying their own scuba bubbles, spiders have developed brilliant ways to deal with water.

Let’s dive into the science in some more detail, and look at how spiders handle getting their paws wet, with examples from our local bush.

Spiders can run across water

Water has surface tension – this acts like a kind of invisible skin that can hold up small, light objects.

Many spiders are tiny and have water-repellent hairs on their legs, so they can stand or run on water without sinking.

For example, fishing spiders wait at the water’s edge and scuttle across the surface to grab insects, tadpoles or even small fish.

If prey escapes underwater, this spider can even hide beneath the water’s surface briefly, then come back up.

Spiders can hold their breath underwater for days

Spiders don’t have gills, so they can’t get oxygen from water like fish do. But they have evolved clever strategies for staying alive if they stay in the water for a long time.

For example, the Australian Sydney funnel-web spider often falls into backyard swimming pools. People might see one and think it drowned, but it can actually survive underwater for hours by holding its breath much longer than a human could.

That’s because it breathes much more slowly than we do. Like many spiders, it has both tracheae (tiny air tubes) and book lungs (they look like a book with many pages) for breathing. Some spiders can close these and become watertight, to hold their breath for a long time.

Some trapdoor spiders have been recorded only taking a breath every six minutes.

Do not burst their bubble

Some spiders take the air with them like a scuba diver.

On the Great Barrier Reef coast, a little intertidal spider called Desis bobmarleyi actually lives part of its life under seawater. At high tide, it hides in a silk-lined air pocket in coral or shells. It uses the long hairs on its legs and body to trap a bubble around itself so it can breathe underwater between the tides. When the tide goes out, this spider comes out to hunt on the wet reef.

And in other parts of the world, there’s the famous diving bell spider, the only spider that spends its whole life entirely underwater.

It weaves an underwater silk web that it fills with air – like an underwater house. This spider can stay underwater for more than a day at a time by letting its air-bubble vessel actively pull oxygen from the water.

Can you spot Desis bobmarleyi among the corals? coenobita/iNaturalist, CC BY

Flood proofing, trapdoor spider style

Some spiders sit tight and make their homes flood-proof. Remember those trapdoor spiders we mentioned? Trapdoor spiders live snug in burrows underground with a silken lid on top (like a little trapdoor).

In areas that get sudden heavy rains, a trapdoor spider might build its burrow with a raised entrance – a bit like a chimney – so water flows around or over it rather than straight in.

Some Australian trapdoor spiders in the outback clay pans have been found to build thick muddy silk doors that fit perfectly like a bath plug into the surrounding soil. The water just goes straight over the top.

Even if water does get in, some trapdoor spiders can seal their bodies and essentially hold their breath. They don’t swim in their flooded burrows, but they can wait out a flood without drowning.

What to do with a soggy spider

If you ever find a spider struggling in water – say in a swimming pool or even in a bucket – you can help as long as you’re careful.

First, always ask an adult before trying to assist a spider. Nobody has died in Australia in 60 years from spider venom. But some (such as the Sydney funnel-web) can still be fatal, so you must be sure not to touch or provoke it.

A good way to save a spider in a pool is to use a net or a scoop with a long handle. Gently lift the spider out and put it on the ground away from the water. The spider might look dead at first, but don’t be surprised if it “comes back to life” as it dries out – just like trapdoor spiders do.

And remember: never poke a spider with your bare hands, even if it seems lifeless. Spiders such as funnel-webs can still bite underwater or right after being rescued, and they will defend themselves if they feel threatened. So, play it safe and use tools or ask an adult or a spider expert to help.

If anyone is bitten, get an adult to seek medical attention immediately.

Next time you’re exploring nature (or even looking into the toilet), keep an eye out for our eight-legged friends and how they interact with water. You might spot a little spider boat captain or an air-bubble diver right in your backyard.

Leanda Denise Mason, Vice Chancellor Research Fellow in Conservation Ecology, Edith Cowan University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Read More........→July 17, 2026