Only One Flu Shot? Maybe!
August 25, 2015 Leave a comment
Can you imagine not having to get a flu shot every season? Apparently two independent teams of doctors have been imagining the same thing.
It has been notoriously difficult to formulate a vaccine against all forms of influenza for a number of reasons. One thing that makes the virus so difficult is that influenza is a shape shifter that can, and does, mutate and change quickly and repeatedly. This means that even if a person develops immunity through an earlier year’s flu shot, he might not be immune to the latest strain of the virus.
A large portion of the human immune response to the flu is directed against a portion of the protein hemagglutinin called the hemagglutinin head. In the last twenty years scientists discovered that some people were able to fight a large swath of flus because their immune systems could develop antibodies that targeted the hemagglutinin stem. Even so though, the human immune system still often cannot keep up with the rapidly mutating stem. This could be partially due to the fact that the stem is hidden while the head is exposed.
Knowing this, the two independent research teams took two different approaches to almost identical notions. With idea to help the body create more stem-specific antibodies in order to help battle more types of influenza, each team decided to focus exclusively on the hemagglutinin stem. Their idea was to create stem-only antigens to incorporate into vaccines, effectively ignoring the hemagglutinin head.
This proved a very difficult task, “Flu is a very large virus with lots of parts. It’s very hard to build a small piece without screwing things up,” Andrew Ward told the Los Angeles Times a structural biologist at Scripps Research Institute. In order to create a stable molecule and not disrupt the response they wished-for for the antibodies, they could not have a single atom out of place.
Incredibly, the two teams were able to create stable molecules and were able to use them to create vaccines which they tested on mice and monkeys and mice and ferrets respectively. They were both able to elicit certain protection in varying degrees.
This, by no means, means that a universal flu vaccine will be available in the short term. However, it paves the way for a type of booster shot that could be available at some point in the future and more protection against the flu than current shots, which only can protect against 3 or 4 strains, says Ward.