Scientists Get Closer to a Zika Vaccine

On June 2, 2016, in Recife, Brazil—the heart of the Zika outbreak—mothers ride the bus with their children, both born with microcephaly, or an abnormally small head. The birth defect is linked to the Zika virus. Image credit: Mario Tama/Getty Images

Zika virus exploded across the world earlier this year, causing a large outbreak of disease in Brazil and spreading to almost 50 countries and territories. While the typical Zika infection is mild, recent reports have strengthened the link between virus infection during pregnancy and the development of microcephaly, a rare neurological condition which leads to a small head and brain in the developing fetus. Zika also has been linked to the development of Guillan-Barre syndrome [PDF], a neurological disorder that can lead to weakness or paralysis.

New research from investigators at Harvard Medical School and collaborators at the University of Sao Paulo, Walter Reed Army Institute of Research, and Ragon Institute has suggested that we’re one step closer to a vaccine to protect vulnerable individuals against Zika virus. The researchers published their findings this week in the journal Nature.

Scientists tested two types of Zika vaccines in mice: a DNA vaccine and an inactivated, whole-virus vaccine. In DNA vaccination, the host's cell takes up the foreign DNA, and the cell then makes the proteins encoded by the DNA included in the vaccine. With an inactivated virus, the host responds directly to the injected proteins that the killed virus produced.

Lead author Dan Barouch, of Harvard Medical School's Center for Virology and Vaccine Research, explained in a press-only teleconference on July 27, “These two vaccine candidates both provided complete protection against Zika virus challenge in mice. To the best of our knowledge, this is the first report of Zika virus vaccine protection in an animal model.”

Importantly, the mice were protected against Zika after a single immunization without any need for a booster. To date, these vaccines have not been tested in pregnant mice, but Barouch notes these studies are ongoing.

The researchers caution that “care should be taken extrapolating from this mouse study to potential human efficacy.” Ben Neuman, a virologist at the University of Reading who was not involved with the study, agrees. He tells mental_floss that “while DNA vaccines work really well in mice, they tend to be a bit hit or miss in other animals, and DNA vaccines have not been particularly effective in people to this point.” No DNA vaccines are currently approved for human use in the U.S.; one is approved for horses against West Nile virus. To date, only one human DNA vaccine has been approved, for Japanese encephalitis virus in Australia.

While this study represents a step forward in the hunt for a Zika vaccine, moving a Zika vaccine from concept to clinic is a difficult prospect. While DNA vaccines may be a long shot, the prospects are also murky for other types of vaccines that have been used for humans, such as attenuated vaccines (live but weakened forms of the virus), which weren’t tested in this study. To create an inactivated vaccine for Zika, enough of the virus would need to be grown in cell cultures to be able to provide a high dose of vaccine to recipients. For a live vaccine, we would have to be careful to be sure that it wouldn’t cause any of the possible developmental or neurological effects that we see with wild-type Zika virus, including microcephaly or Guillain-Barré syndrome.

Another concern for a Zika vaccine is the potential to make other diseases, caused by related viruses, more serious. Zika is a Flavivirus and related to other viruses in this genus, including West Nile, yellow fever, Japanese encephalitis, and dengue. A second infection with dengue can actually be worse than the first, due to a phenomenon called antibody-dependent enhancement of infection. There is concern that there is potential for a Zika vaccine to induce this response.

“Antibodies are sticky molecules that float around in the blood, and many cells are covered with molecules that can catch passing antibodies," Neuman explains. "A virus like Zika may miss its chance to infect a host cell that it is poorly adapted to recognize. But if it is covered in antibodies, the virus has a better chance to infect because the antibody acts as a bridge—the cell holds onto the antibody, which sticks to the virus. This is why dengue virus is usually more severe the second or third time you catch it—the virus gets an infectious boost from antibodies left over from earlier infections. It would be wise to have a better idea of how antibodies will affect Zika virus before we start vaccinating lots of people.”

This unwelcome outcome could happen in reverse as well: The recently released dengue vaccine may make infection with Zika virus more serious, as recent laboratory models have suggested.

We’ll soon have a better idea of antibody production due to Zika vaccines in human trials. Co-author Col. Nelson Michael, of the Walter Reed Army Institute of Research, confirms to mental_floss via email that trials of the inactivated vaccine tested in this research will be moving into Phase I human trials in October—so these vaccines may soon become a reality.

97 Percent of Us Are Washing Our Hands All Wrong

Most of us know the importance of washing our hands, but we're still pretty clueless when it comes to washing them the right way. As CNN reports, we fall short of washing our hands effectively 97 percent of the time.

That number comes from a new study conducted by the U.S. Department of Agriculture that looked at 383 participants in a test-kitchen environment. When they were told to wash their hands, the vast majority of subjects walked away from the sink after less than 20 seconds—the minimum hand-washing time recommended by the Center for Disease Control and Prevention. Many of them also failed to dry their hands with a clean towel.

The researchers had participants cooking and handling raw meats. Because they didn't wash their hands properly, volunteers were spreading potentially dangerous germs to spice jars 48 percent of the time, contaminating refrigerator handles 11 percent of the time, and doing the same to salads 5 percent of the time.

People who don't wash their hands the correct way risk spreading harmful microbes to everything they touch, making themselves and those they live with more susceptible to certain infections like gastrointestinal illness and respiratory infections. Luckily, the proper hand-washing protocol isn't that complicated: The biggest change most of us need to make is investing more time.

According to the CDC, you need to rub your hands with soapy water for at least 20 seconds to get rid of harmful bacteria. A helpful trick is to sing "Happy Birthday" twice as you wash—once you're finished, you should have passed the 20-second mark. And if your bathroom or kitchen doesn't have a clean towel to dry your hands with, let them air-dry. 

[h/t CNN]

This Mysterious Condition Makes People Think Bugs Are Crawling Under Their Skin

After seeing a spider or beetle scurry past you, it’s normal to get a creepy-crawly feeling, even if you know there’s nothing on you. For many people, though, the persistent sensation of phantom insects or parasites crawling underneath their skin—known as formication—is very real, Newsweek reports.

The condition is called delusional infestation, and although cases have been documented around the world, there hasn’t been enough research to determine if it’s a skin condition or psychological disorder. However, two new studies are attempting to shed light on the mysterious ailment that can cause symptoms such as itching, fatigue, joint pain, rashes or lesions, and difficulty concentrating. Some people have reported picking “fibers” out of their skin.

Researchers from the Mayo Clinic and Denmark’s Aarhus University Hospital believe tens of thousands of Americans could have this condition, making it more common than previously thought. Their study, published in the journal JAMA Dermatology, found that people with the condition are often “resistant to medical evidence [showing that there is no infestation] and reluctant to pursue psychiatric evaluation.” Some patients, convinced that they have something crawling underneath their skin, self-harm with tweezers, bleach, or razor blades.

The researchers stopped short of calling it a psychological condition, but they did conclude that schizophrenia, dementia, other psychiatric conditions, and drug use can trigger delusional infestation in some cases, Science News reports.

Another new study, published in the journal Annals of the Academy of Medicine of Singapore [PDF], also seemed to favor a psychological explanation for the condition. The researchers noted that Chinese patients with the condition were treated with antipsychotics, and 10 of the 11 patients with isolated cases of delusional infestation (who had no other underlying disorders) improved with medication.

However, other researchers have drawn different conclusions, arguing that the condition is the skin's response to “tick-borne pathogens” typically associated with Lyme disease. The condition has gone by several names over the years, including Morgellons disease—a term coined in 2004 by a medical researcher and mother who says she found “fibers” on her young son’s skin after he kept scratching at the "bugs" he claimed were there. Regardless of the origin, what's clear is that the condition has very real consequences for those who suffer from it, and more research is needed to find suitable treatments.

[h/t Newsweek]


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