Deep sequencing, A Clever and Promising Way to Handle Next Year's Flu!
Flu, seems to be the No. 1 topic this year. It changes incredibly fast, just like the âGolden Snitchâ in a Health Quidditch. But the good news is deep sequencing, our âMagic Harryâ, is almost there.
Flu evolution is always in scientistsâ to-study-list. As the flu virus is changing its face and playing with you all the time, even one patient can have various mutations of the virus.
Letâs take the example of H3N2, a major subtype of flu that visits us almost every winter. If it evolves and adapts well, only one variant of the H3N2 virus can replace all other H3N2 viruses, and it only take a few years. And when you think you got enough humans immune to it, sorry, the whole cycle begins anew.
Since the turnover is unsure and scientists need to predict it ahead of time for making enough vaccine ready. And you can imagine the possible gap here. For example, in 2015, the flu shot was only 23 percent effective against that yearâs circulating H3N2 variant.
How to solve the problem? Finally, we find the magic deep sequencing.
Deep sequencing, put it simply, is totally a tool for identifying rare mutations. For example, you have one sample, if you use the deep sequencing to test it for a few times, you will get its average virus mutations. If the deep sequencing can be conducted by at least 200 times, you will see those rare mutations of the flu virus.
Katia Koelle, a virologist at Duke, she and her lab has used the deep sequencing on the flu viruses in healthy people, who are sick for only a few days. Of course, the virus keeps envolving. According to Koelle, itâs hard for a new variant to get to high frequency in a short amount of time, namely, a beneficial new mutation may arise, but the speed of your immune system clearing the infection is generally faster than the speed of the variant becoming common enough to spread to another person.
As to predict the future of flu by deep sequencing, we could ask help from children, pregnant women, and people with obesity, as well as immunocompromised cancer patients, Elodie Ghedin says, a parasitologist and virologist at New York University. Because these people are more likely to experience longer flu infections. Deep sequencing in infected people, especially in those groups, could help scientists keep close watch on emerging mutations.
Elodie notes that prediction and vaccine selection for flu is hard as it has not gotten much traction. But now, deep sequencing is a totally promising way. Also, cost of deep sequencing is getting acceptable since the plunging cost of all DNA sequencing is more practical.
With deep sequencing, youâll find a lot of variants, except for the common variant and rare ones. And if the deep sequencing is conducted in an enough and right manner, flu variants end up dominating the world can be well expected.