The timing and design of vaccines used to immunise against lung infections may have to change in the light of research findings by Imperial College scientists (1).
The research published today in the Journal of Experimental Medicine, shows for the first time that the previous infection history of an individual greatly affects the duration and severity of subsequent lung infections.
These findings stress the important yet ignored role that previous infection plays in the design of vaccines.
Currently, most vaccines are tested on animals that have not previously been exposed to other lung infections. This is quite unrealistic when you are trying to vaccinate a human population which would have seen number of infections at various stages of their lives, says Dr Tracy Hussell of the Department of Biochemistry, Imperial College, the senior author on the paper.
Dr Tracy Hussell and her collaborators work on Respiratory Syncytial Virus (RSV). They show that mice which have been previously infected with influenza do not suffer the characteristic symptoms of RSV - weight loss, illness and lung eosinophilia - when they are subsequently infected with RSV. (See Notes to Editors 1 - 4).
What we have found is that one viral infection in the lung profoundly changes the way we respond to an unrelated infection at the same site. By educating itself, the immune system actually improves the way we respond to a second unrelated infection, said Dr Hussell.
In the 1960s children were vaccinated against RSV with an inactivated, dead form of the RSV virus (5).
Dr Gerhard Walzl, first author on the paper said: When these children later encountered RSV virus in the community, the older children did not get as sick as vaccinated new-borns. Presumably, the older children would have encountered a number of infections in their lungs before they received the vaccine. This will have protected them from the harmful effects of the inactivated RSV vacc
Contact: Taslima Khan
Imperial College London