A paper published today in Nature has reported the trial results of two types of vaccine against the Zika virus in mice. In response to this report, the BSI has issued the following statement:
Professor Peter Openshaw, President of the British Society for Immunology and Professor of Experimental Medicine at Imperial College London, said:
“In this very interesting study, the authors tested two types of vaccine against Zika virus infection in mice. They found that either a DNA vaccine or the conventional alum adjuvanted, formalin-inactivated vaccine induced antibody responses and protected against infection challenge.
“It’s reassuring that both vaccines worked in mice. The authors provide nice evidence that the levels of antibody produced are sufficient for protection and that depleting T cells has no discernible effect on protection once antibody has formed. They also establish what sort of levels of antibody might be needed for protection.
“There are some caveats, however. First, this is a study in mice; DNA vaccines that work in mice have a sorry history of not working in humans. I would have greater confidence in the classical inactivated vaccine working in humans. Second, the antibody levels were measured at 3 weeks, and the challenge with live virus was at 8 weeks. It’s not clear how long the immune response would be there for, and if a diminishing level of antibody might be protective or even disease-enhancing. The readout of infection is viral load and not disease severity – the two don’t always go together.
“These studies are a good step forward and give reason to be optimistic that vaccines might work in people. However, it is essential to move to human studies as soon as possible. By the time human vaccines are ready, many of the vulnerable population will have already been naturally infected. The purpose of vaccination will presumably be to protect travellers and those wishing to become pregnant. It will be vital to see how vaccines will work in such situations and how the practical and economic barriers to vaccine deployment can be overcome.” The full paper that this comment is in response to can be found at:
Barouch et al. Nature DOI: 10.1038/nature18952
Image credit: Centers for Disease Control and Prevention