WASHINGTON – Wanted. Volunteers willing to be infected with the virus Zika for science
may sound strange, but researchers are planning only a study of this type – this winter, when mosquitoes do not bite -. To help accelerate the development of vaccines Zika very necessary
The search for a vaccine began less than a year ago, as massive outbreak of Brazil revealed that Zika, once dismissed as a virus discomfort, can fetal brain damage if a woman is infected during pregnancy.
The article continues after the announcement
Now, researchers in the United States have begun safety testing of the two candidates for vaccines and vaccine candidates more are about to enter the evidence preliminary soon. Anyone who looks promising will have to be tested in thousands of people in parts of Latin America and the Caribbean-which was strongly affected by the virus transmitted by mosquitoes -. The only way to test an experimental vaccine really
Even if all goes well, a vaccine may not be available for general use in the short term.
But a different type of research may also provide clues for vaccine development. It is called study of human exposure , when healthy – and not pregnant -. People agree to deliberately injected with a virus that mimics the natural infection, while scientists track how their bodies react
the first question is even more basic: How much of the virus is needed to infect someone
If government regulators agree, the researchers could find out by injecting paid different amounts of Zika virus grown in the laboratory and in December in a Baltimore hospital volunteers. This information will help researchers later when they are ready to try an experimental vaccine Zika.
“We are thinking about these protocols human challenge not only as an important step vaccine development, but as a means to learn more about Zika,” said Dr. Anna Durbin, Johns Hopkins Bloomberg Public Health, who directs the work. “We can see things that simply can not be done in a naturally infected person.”
Some questions and answers about the development of vaccines Zika:
Q 😕 What potential vaccines are first in line
A :. Two-called DNA vaccines have begun preliminary safety tests, one made by the National Institutes of Health and the other by pharmaceuticals Pennsylvania-based Inovio
mark a new type of technology. Traditionally, vaccines are made with a dead or weakened virus to train the body’s immune system to recognize and fight the infection. DNA vaccines may be easier to do. The scientists used a circular piece of DNA, called a “plasmid”, to carry genes that prompt the body to produce certain proteins Zika virus, alerting the immune system.
That piece of deception worked in animals. Phase 1 studies in dozens of people will check for safety, and if vaccines accelerate human immunity enough to warrant further testing.
Q: What else is in the pipeline
A: “We are now in a race of time to get the best vaccine,” said Dr. Anthony Fauci , director of the National Institute of Allergy and Infectious Diseases, NIH
Several candidates are important because there is no way to predict what will work best. DNA vaccines simply were ready for testing in humans for the first time.
In October, safety tests are set to begin using the vaccine with more traditional killed-virus, developed by the Institute of Walter Reed Army Research.
The NIH is also developing a vaccine against the use of live virus but debilitado-, the type thought to trigger especially long-lasting immune protection. That is the kind used to protect against rubella , which back in the 1960s caused an epidemic of birth defects.
Q 😕 If the first candidates are safe, what happens after
A :. Fauci expects to open the studios next steps in January, enrollment from 2,400 to 5,000 people in areas where Zika is still spreading widely to test whether vaccinated are less likely than unvaccinated infected
Q : vaccines for pregnant women
a: not at this time. It is difficult to test new products during pregnancy. In addition, a fetus may be vulnerable to Zika even before a woman realizes she is pregnant.
The goal instead is to vaccinate women of childbearing age and their sexual partners – because Zika can also be transmitted through sex -. Well before pregnancy occurs never
Q: Where studies human challenge come in
A: hitting someone with Zika is faster than expected to a mosquito bite them to see if an experimental vaccine provides protection. But first you have to find what causes Zika Durbin dose of infection, to ensure that it is giving enough vaccine challenge.
That’s what the study scheduled for December would. Volunteers given different amounts of Zika remained in a hospital unit Hopkins for 12 days, to ensure that the virus had cleared the bloodstream, and would have to agree to use condoms for a while afterwards to avoid any possibility of sexual transmission. The second round of research would be to recruit volunteers who received an experimental vaccine, trying to infect them with Zika six months after their decision.
the extra benefit: tracking people from the time they are exposed to Zika could also shed new light on how the virus affects the body – such as how long is infectious in the blood, semen and other body fluids and to what extent the immune system fights off.
Q: has done this before
A: human exposure studies are rare because they are difficult to make and expensive. But Durbin did recently just such research to test a vaccine against dengue, a hazardous cousin Zika, and does not expect difficulties in recruiting volunteers for Zika studio time that regulators had been met, it can be carried out safely.
Q: What about the fight for federal funding for Zika
R: In February, the Obama requested $ 1.9 billion for the fight of the nation against Zika, including vaccine development, but Congress has not approved anything like that. With the existing money is running out, federal health officials are taking the funds for other diseases to survive until the end of the year -. But Fauci said, NIH only need $ 196 million more in 2017 to avoid delays in vaccine research
– Lauran Neergaard