Human Semen Can Host At Least 27 Different Viruses

When scientists discovered that the Zika virus can survive in semen for up to 6 months, people exposed to the disease—especially those hoping to have children—were horrified. It’s now known that the virus can be sexually transmitted up to 41 days.

Now, a new meta-analysis has found that 26 other viruses can also live in human semen and go on to infect the bloodstream.

Those include the viruses that cause Ebola, HIV, hepatitis B, and herpes.

After reviewing more than 3800 scientific publications, the authors also found evidence that at least 11 viruses can live in the testes, including those that cause influenza, dengue, and severe acute respiratory syndrome.

These viruses could potentially be found in semen, too, the authors say. Though not all 27 viruses are capable of person-to-person transmission, they can have other serious consequences, like reducing fertility or increasing the risk of acquiring a sexually transmitted disease.

Some of these viruses can even cause mutations in the DNA of sperm, which could then fertilize an egg and pass along the virus-induced mutations to future generations. The findings, published last week in the Centers for Disease Control and Prevention’s Emerging Infectious Diseases journal, suggest that more viruses can live in semen than previously thought.

But the authors warn that far more research is needed to understand how and whether the viruses can be sexually transmitted and exactly which viruses remain viable in semen, for how long, and at what concentrations.

Souce: Science Mag
By: Karl Gruber

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New Antibody Attacks 99% of HIV Strains

Scientists have engineered an antibody that attacks 99% of HIV strains and can prevent infection in primates.

It is built to attack three critical parts of the virus - making it harder for HIV to resist its effects.

The work is a collaboration between the US National Institutes of Health and the pharmaceutical company Sanofi.

The International Aids Society said it was an "exciting breakthrough". Human trials will start in 2018 to see if it can prevent or treat infection.

Our bodies struggle to fight HIV because of the virus' incredible ability to mutate and change its appearance.

These varieties of HIV - or strains - in a single patient are comparable to those of influenza during a worldwide flu season.

So the immune system finds itself in a fight against an insurmountable number of strains of HIV.

Super-antibodies

But after years of infection, a small number of patients develop powerful weapons called "broadly neutralising antibodies" that attack something fundamental to HIV and can kill large swathes of HIV strains.

Researchers have been trying to use broadly neutralising antibodies as a way to treat HIV, or prevent infection in the first place.

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The study, published in the journal Science, combines three such antibodies into an even more powerful "tri-specific antibody".

Dr Gary Nabel, the chief scientific officer at Sanofi and one of the report authors, told the BBC News website: "They are more potent and have greater breadth than any single naturally occurring antibody that's been discovered." 

The best naturally occurring antibodies will target 90% of HIV strains.


"We're getting 99% coverage, and getting coverage at very low concentrations of the antibody," said Dr Nabel. Experiments on 24 monkeys showed none of those given the tri-specific antibody developed an infection when they were later injected with the virus.

Dr Nabel said: "It was quite an impressive degree of protection." The work included scientists at Harvard Medical School, The Scripps Research Institute, and the Massachusetts Institute of Technology.

'Exciting'

Clinical trials to test the antibody in people will start next year.

Prof Linda-Gail Bekker, the president of the International Aids Society, told the BBC: "This paper reports an exciting breakthrough.

"These super-engineered antibodies seem to go beyond the natural and could have more applications than we have imagined to date.

"It's early days yet, and as a scientist I look forward to seeing the first trials get off the ground in 2018. "As a doctor in Africa, I feel the urgency to confirm these findings in humans as soon as possible."

Dr Anthony Fauci, the director of the US National Institute of Allergy and Infectious Diseases, said it was an intriguing approach.

He added: "Combinations of antibodies that each bind to a distinct site on HIV may best overcome the defences of the virus in the effort to achieve effective antibody-based treatment and prevention."

Source: BBC News
By: James Gallagher
Health and science reporter, BBC News website

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