New Developments of Zika Vaccine

On December 4, the NIH released a statement explaining that recent Phase I clinical trials are showing that a new, inactivated vaccine against Zika virus has been shown to be effective and safe. The research is being conducted in the Walter Reed Army Institute of Research. The vaccine is an inactivated vaccine with Zika virus that still has its protein shell in order to be recognized by the immune system as something to attack. This is ultimately safer than creating a live vaccine with live virus that has the potential to replicate and cause diseases within humans.

The study had 67 participants, of which 55 received the vaccine and 12 had the placebo. The vaccine consisted of two intramuscular injections that were separated by four weeks. The blood samples of participants were tested at various times after the distribution of the vaccine. In 90% of the participants, antibodies to Zika virus were detected after just four weeks from receiving the second dose.

One of the biggest concerns with Zika infection is the congenital anomalies that can occur. It is currently unclear how many antibodies need to be present in order to protect against these viral effects. However, the antibodies produced in humans in this trial were then transferred to mice. After being infected with Zika virus, the mice were able to respond very effectively to the virus given the antibodies they had which provides promising strength of the vaccine. 

Other vaccines are currently also in development against Zika. These other vaccines target separate parts of the virus and come in different forms, such as DNA vaccine, mRNA vaccine, and a live-attenuated vaccine. The program leader of this research at the Walter Reed Army Institute of Research is hopeful. He states that "Zika remains a threat to U.S. military personnel and families of service members. We aim to develop a vaccine to protect the military, as well as the global community."

Source: https://www.nih.gov/news-events/news-releases/trials-show-inactivated-zika-virus-vaccine-safe-immunogenic

-Alexandra