Pioneering new research into respiratory syncytial virus (RSV) may have overcome the barriers that have impeded the development of an effective vaccine against the deadly virus.
RSV is a virus that causes lower respiratory tract infections and is a major cause of childhood morbidity and mortality worldwide. Attempts to develop vaccines against the virus in the 1960s were dogged with disastrous results, with the formalin-inactivated vaccine(FI-RSV) causing the RSV disease to actually worsen in many cases. The cause for this reaction to the vaccine is so far unexplained, and so researchers have since been hesitant about exploring RSV vaccines further. However, pioneering new research may have solved the conundrum once and for all and thus potentially opened up a significant new opportunity to develop an effective RSV vaccine.
What did the trial show?
Researchers at Imperial College London performed trials on mice to show that the FI-RSV vaccine used in the 1960s trials caused white blood cells, the CD4+ T cells, to accumulate in the lungs and prevent oxygen delivery with often fatal consequences. The regulatory white blood cells, the Tregs, were simultaneously depleted, leading to an uncontrolled state of inflammation in the lungs. The body's immune reaction to the vaccine was therefore too strong and sustained. The research team then tested the effect of giving chemokines to the vaccinated mice. The chemokine proteins successfully reduced the dangerous levels of inflammation in the lungs and therefore reduced the dangerous effect of the vaccine.
Why is it important?
This discovery is important because it may allow researchers to find new ways to develop an effective vaccine against RSV. The previous difficulties encountered in RSV vaccine trials have acted as a deterrent against research in the field, but now that scientists are piecing together the puzzle about what went wrong in the past then this may stimulate new research into RSV vaccination in the future.
Do you think that this trial is significant?
More information on the trial can be found here.
If you would like to hear more about RSV vaccine development and many other topics, come along to the World Vaccine Congress & Expo 2013 in Washington DC.