US Enrols Volunteers Into Large Zika Virus Vaccine Test

U.S. health officials have begun enrolling volunteers for critical next-stage testing of an experimental vaccine to protect against Zika, the mosquito-borne virus that can cause devastating birth defects in pregnant women.

The first volunteer was vaccinated Wednesday at Baylor College of Medicine in Houston, as the National Institutes of Health gears up for a two-part study that aims to enroll at least 2,400 people in Texas, Florida, Puerto Rico and five at-risk countries: Brazil, Mexico, Panama, Costa Rica and Peru.

Zika has caused an epidemic of birth defects — including babies with abnormally small heads and brains — in parts of Latin America and the Caribbean, and continues to spread to a creeping list of other countries. For the U.S. the risk has largely been to travelers, although mosquitoes spread the virus in parts of southern Florida and Texas last year, where health officials remain on guard.

But while Zika largely disappeared from the headlines over the winter, mosquito season is fast approaching — and the risk persists internationally.

“It is imperative that public health research continue to work to contain the spread of the virus,” Dr. Anthony Fauci, director of NIH’s National Institute of Allergy and Infectious Diseases, said Friday in announcing the $100 million study.

First-stage safety testing of a so-called DNA vaccine against Zika signaled no side effect concerns, Fauci said — allowing the NIH-created shots to progress to the next stage of testing that will help tell if they really work.

It’s a two-part study. First, researchers will evaluate 90 healthy adults given different doses to determine the best one. Those volunteers will be tested at Baylor, the University of Miami and University of Puerto Rico.

Once the correct dose is picked, the larger part of the study could begin as early as June at those sites and additional ones in the at-risk countries — giving 2,400 volunteers either the experimental vaccine or dummy shots. Pregnant women can’t receive the experimental shots but women of child-bearing age can enroll. All the volunteers will be tracked for nearly two years to see if the vaccine really protects against Zika infection.

This is a totally new kind of vaccine. Traditionally, vaccines are made using a dead or weakened virus to train the body’s immune system to recognize and fight that infection.

In contrast, the DNA vaccine works through trickery: It’s made with a circular piece of DNA carrying genes from the Zika virus that, once in the body, make particles that resemble Zika enough to alert the immune system but cannot cause infection.

The NIH also is testing the safety of some more traditional Zika vaccine candidates, but the easier-to-make DNA vaccine was the first ready to advance to this second stage of human testing.

Don’t expect a vaccine to be widely available any time soon. If Zika causes lots of illness this year, Fauci said researchers may have clues by early 2018 about how well the shots work — but if natural infections slow, they’ll need many more volunteers to get an answer.

For most people, Zika causes no symptoms or only mild ones such as fever, aches, an itchy rash or red eyes. But aside from the pregnancy risk, Zika sometimes causes a temporary paralyzing condition called Guillain-Barre syndrome, and there’s some evidence that it also may trigger heart problems in adults who previously were healthy.

And Zika is likely to become endemic in parts of the Americas, Fauci said. “I’m totally intent on getting this vaccine to the point it can be a usable vaccine.”

1 Comment

  1. jonathan harris Reply

    This is an amazing development, considering the WHO still hasn’t established that Zika is the actual cause off birth defects – it has only been suggested, by consensus, by the ‘experts’, and these guys still think Dengue fever might be the culprit. Please read any WHO article on the subject and look for firm evidence, there isn’t any. However according to numerous studies which were published in 2015, a wave of birth defects was caused after mosquito grounds were treated with aerial spraying which contained substances which caused birth defects in lab rats/monkeys. However, the industries behind these products put their marketing people into gear, and the pharma companies did the same, smelling a fortune in the development of a virus. Today there is still no proven the direct connection between Zika and birth defects. If Zika was the culprit then there would have been another surge in birth defects in the summer of 2016, but this didn’t happen, and scientists don’t know why ( ). In Columbia, north of Brazil, thousands of cases of Zika occur every year but the resultant birth defect rates are in line with non-zika country national averages.
    All of this was reported during the lead-up to the Rio Olympics, but ignored in the mainstream press.
    Also , anyone heard of one case of microcephaly from anyone visiting the Olympics.
    This whole issue has been wrapped in so much fake news and so much pharma-driven fear mongering that truth will never be known.

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