There is a news story circulating this week about the idea of a universal influenza vaccine that may not require annual booster doses. A group of scientists in the United Kingdom have developed a vaccine like this and they are testing it.
Influenza viruses change (mutate) very quickly. The parts of the virus that cause infection are molecules called proteins on the surface of the virus. Some artists picture these molecules as looking sort of like mushrooms on the virus surface, although we really don’t know exactly what they look like. The tops of these proteins cause the virus to attach to our respiratory tract and cause infection, and those parts change. We make new vaccines out of these new proteins each year as they mutate.
The people working on this project asked an interesting question. The tops of these proteins change a lot, but other parts of these proteins and other viral proteins don’t change as much. Why don’t we make a vaccine out of the parts of the proteins that don’t change so much and see if that works?
Apparently it does work. Humans develop antibodies (immunity) against these stable molecules too, and they may be protective. Maybe changing the vaccine recipe will allow us to give the vaccine less often. The interval would depend on how long our immunity lasts, not on how quickly the virus changes.
The story predicts that such a vaccine may be ready in five years. I would not count on that. If this approach seems to work, we may know how good it is in five years, but it takes a long time to test vaccines before they are approved by the FDA, and influenza is a seasonal disease, so studies can only be done during certain months of the year. It is nice to know that improved vaccines may be coming.