It's the peak time of the year to get a flu shot, according to the Centers for Disease Control and Prevention. The best time to get a flu shot is the end of October or early November, that way the body has time to create the antibodies that help fight off the flu during the peak season.

While the vaccine varies in effectiveness each year, the CDC still recommends that everyone in good health over the age of six months old get the flu shot. Different flu shots are made for people of different age groups, but those under six months should not get any type of flu shot, according to the CDC.

The flu vaccine is generally 40 to 60 percent effective the CDC has found through multiple studies. Meaning those who get the vaccine have a lower risk of getting the flu, but exactly how low that risk is can vary from season to season and from flu to flu.

Part of how effective a vaccine will be on a person has to do with their health as a whole as well as their age. The second determining factor in how effective the vaccine will be is how well it matches the actual flu viruses making the rounds that season. When the vaccine doesn’t match the strains of the flu, it tends to be less effective.

While how much the vaccine benefits the individual can vary on a person to person basis, more people getting their vaccines is better for public health as a whole. “Getting vaccinated yourself may also protect people around you, including those who are more vulnerable to serious flu illness, like babies and young children, older people, and people with certain chronic health conditions,” said the CDC.

This season’s flu vaccine was updated so that it better matches the circulating viruses, which meant changing the B/Victoria component and updating the A(H3N2) component. Both the nasal spray and the vaccine are available this year but the intradermal vaccine is unavailable.

The vaccines this year were created to protect against three or four specific viruses depending on which vaccine it is. Some cover three viruses others cover four. Those three that they both cover are A/Michigan/45/2015 (H1N1)pdm09-like virus, A/Singapore/INFIMH-16-0019/2016 A(H3N2)-like virus (updated), B/Colorado/06/2017-like (Victoria lineage) virus (updated) and some also protect against the plus B/Phuket/3073/2013-like (Yamagata lineage) virus.

**Source:** https://www.newsweek.com/flu-vaccine-2018-season-effective-how-year-1197457