Millennials are the least likely generation to get their flu shot because they are being influenced by anti-vaxxers, a new survey reveals.

Researchers from the American Academy of Family Physicians (AAFP) found that more than half of Americans - 55 percent - in their 20s and 30s did not get the vaccine for this flu season.

The majority said they didn't receive the shot because they either didn't have the time or they'd forgotten. 

But the survey also found that the anti-vaccination movement may to blame for the low rates of millennials being immunized with nearly two-thirds saying they agree with anti-vaccination beliefs.

'It is very alarming to see how people are being influenced by the anti-vax movement,' said Dr Alexa Mieses, a practicing family physician in Durham, North Carolina in a statement.

'We need to make sure that...communities are educated about the importance of vaccines and that they understand the source of the rhetoric they're hearing. It's clear they are being influenced by myths and misinformation, and it's critical that the facts reach them too.'