With coughs and sniffles abound, many are eager to get the flu vaccine — while others are avoiding the shot like, well, the plague.

While the nasal flu vaccine has been largely unavailable in recent years, medical experts are urging the public to get the vaccine in shot form as the colder months set in.

The flu shot contains an inactive dose of the influenza virus, which prompts the immune system to create antibodies to fight off the potentially deadly viral infection.

The Vaccine Causes the Flu

Dr. Denise Pate, Internal Medicine Doctor at Medical Offices of Manhattan, tells PEOPLE she’s encountered several patients who were wary of the shot due to long-circulated rumors that it causes illness.

“They think it’s gonna give them the flu, it’s a very common thing,” she says. “Because the virus is inactive, it absolutely cannot transmit the infection.”

Pate also noted that while the shot contains inactive influenza, the nasal vaccine held the live virus: “They found that that has not been effective.”

“There are people who should not be exposed to the live virus … the elderly, the very young, pregnant women are not allowed to get the live virus.”

Patients May Experience Flu-Like Symptoms Shortly After Getting the Vaccine

Pate says that, for up to a day after getting the shot, some may experience body aches, soreness around the injection site and “may feel a bit feverish.”

“I think it’s important to recognize the side effects of getting the shot versus what the actual flu is,” she says. “It is common that when you do get the flu shot, you’re taking in the inactive virus so you’re body is getting exposed to something.

The Flu Shot is ‘Never 100 Percent Foolproof’

Dr. Pate says that, much like any other vaccine, there is not a 100 percent guarantee that a person will not get the flu.

“But if you do get the flu shot, the possibility of getting the flu is severely reduced and if you do come across the virus and if you do develop symptoms, it would be far less severe than if you did not get the shot,” she tells PEOPLE.

“There is still a possibility that people will get the shot and will still come down with the flu, but those cases are much more mild.”

Dr. Pate adds that the vaccine takes up to two weeks to take full effect — “So there’s a possibility that if someone got it today and next week they got exposed with the flu, they could come down with the flu because the vaccine isn’t protecting them yet.”

“I really don’t think that [the vaccine] is linked to autism,” Dr. Pate says. “This topic is really, really controversial … but I really don’t think there is any correlation.”

Skeptics have suspected the link because a mercury-containing, organized compound has been used as a preservative in some vaccines.

Dr. Pate says that though there has been an increase in autism in recent years, that’s likely because the condition is simply being recognized more often.

“It’s something we’re diagnosing more because we’re more aware of it,” she says. “Years ago, people with autism would just be called ‘slow’ or ‘delayed.’ ”

She adds: “People have been getting flu shots for many years and I don’t think there’s a correlation.”