Science Buddies: "Ask an Expert"

Hello,

While conducting research on the experiment "BLASTing Flu Viruses", I found that the common strains are almost all around 97% similar to the vaccine strain. So, if the influenza virus that people got is only 3% different from the vaccine, is that just an example of viruses changing rapidly and a reason why the flu is hard to cure?

Thanks!

Hello,
To understand why only 3% of a flu vaccine is different than the actual flu virus I would suggest learning more about how vaccines work. If you do a simple internet search using the term vaccine on or lookit up on Wikipedia you should be able to get an explanation around that. If you have trouble understanding what you read feel free to ask more questions here. In regards to viruses mutating. Yes, that is the reason that vaccines are not always effective.

Hope this helps get you started!

Also, do virus sequences change over time? Because in my data I see that some flu viruses are common across multiple generations. But if they are very similar to the viruses in the vaccine, do they change to slip past the vaccine?

I am thinking they do evolve because of the different sequences for different years and when and where it was isolated, but I'm not sure.

Hi,

Yes, virus sequences change over time - minor changes... usually in the section that expresses cell surface proteins - these are the proeins that antibodies recognize. So the virus mutates the proteins, the antibodies can't recognize them anymore, and we need a new vaccine.