Promising approaches to the Zika vaccine

Since the last Zika virus epidemic, a vaccine has been feverishly worked on. The first tests are promising and the researchers are optimistic that there will soon be a vaccine. A delay is unfortunately not excluded, because there is a problem with the test persons.

Computer illustration of Zika virus. Soon there could be first vaccines.

The Zika virus spreads over mosquitoes. Fighting them is difficult - that has been shown in recent months in Brazil. Therefore, numerous research groups around the world are working on vaccination against the virus. Because when pregnant women infect with Zika, the embryos threaten serious damage. With a vaccination one could prevent that.

In the case of a promising candidate for protection against Zika, a piece of hereditary information of the virus, a piece of DNA, suffices, says Anthony Fauci.

"We are building the genetic plan for a protein from the surface of the Zika virus into a DNA ring." When we inject such rings into a human, his cells begin to produce Zika proteins, but his immune system develops antibodies, which he hopefully does Against the Zika virus itself. "

First test results look positive

Anthony Fauci is the head of the National Research Institute for Allergy and Infectious Diseases in the United States, NAIAID, and one of the leading vaccine experts in the US. His institute is working with several research groups on very different approaches for a vaccine against Zika.

The development of the DNA vaccine went so fast, because Anthony Fauci and his colleagues had already developed a vaccine against another virus according to the same principle. At Zika, the first results are positive, he says.

"We tested it first in mice and monkeys, and then in a first clinical study in about 80 people, the subjects were well tolerated, and it has produced a promising immune response, and now we are starting with larger studies that really test the efficacy. "

Parallel to the DNA vaccine, other candidates are tested in clinical trials based on other techniques: some vaccines use RNA as the genetic material rather than DNA. They are similar to the DNA-based vaccines, but they skip a processing step in the cell. Therefore, smaller doses are sufficient to protect people.

Clinical tests begin

Another approach is the way the developers of well known vaccines have already gone, for example against rubella or the smallpox. They use a weakened live virus. This is also so far developed that it is now being tested on humans. In addition, researchers have assembled a so-called chimeric vaccine virus from dengue and zika virus. Faucis Forschungsinstitut is involved in all these projects as donors or with know-how.

"There are therefore at least four different platforms and for each one several developments, therefore, clinical tests are now starting for a half to a dozen vaccine candidates."

Safety is even more important in Zika than in vaccinations, because the overwhelming majority of infected people do not even notice the disease. However, Zika would not be the first vaccine administered to large sections of the population to protect a small group, says Anthony Fauci.

"Even the rubella causes a relatively mild disease, but everyone is vaccinated against it, the most important target group is women of childbearing age, they have to protect it before they can get children So you have to vaccinate boys, even in the childhood. "

Waiting for test persons

Whether the Zika vaccination - like the rubella vaccination - is already given to small children, how many doses of the respective preparations are necessary - all will be shown only the large tests. However, it is now already clear that vaccination can take effect after only a few days and can protect Zika for a lifetime.

The researchers have to hurry with their clinical trials, because the Zika epidemic has reached its peak, more and more people are immune to the virus. This is why researchers are excluded from the experiment. But Anthony Fauci remains calm.

"If there is a new outbreak in Puerto Rico in July, August, we can test the vaccines there, then we can evaluate the data in the second half of the year and we know already in early 2018 whether these vaccines Or not. "

If, on the other hand, the number of cases decreases, it would take two more years for the researchers to test the vaccines for a sufficient number of people to tell them how effective they are.