School is back in session, and with the new school year comes new recommendations for the upcoming flu season.

Officials at the American Academy of Pediatrics (AAP) are urging parents to make sure their children ages 6 months and up get a seasonal flu shot during this school year.

The organization, however, recommends against a commonly used nasal spray, agreeing that method has been ineffective against certain strains of the flu that have been prominent the past three seasons.

The academy also recommends that pregnant women, women who are breastfeeding, and healthcare professionals get flu vaccinations. It suggests vaccinations start no later than October and be available through June 30.

“Protecting children from influenza with the vaccine, early in the respiratory season, is the best protection pediatricians and parents can provide,” Dr. Wendy Sue Swanson, M.B.E., F.A.A.P., a pediatrician at Seattle Children’s Hospital, said in a statement.

The AAP’s recommendations were published today in the journal Pediatrics.

The group’s guidelines come less than three months after the Advisory Committee on Immunization Practices of the Centers for Disease Control and Prevention (CDC) recommended against the use of the nasal spray, or active vaccine, for the 2016-17 flu season.

The recommendation was made after research groups found that the nasal spray was less effective than the shot, or inactive version of the vaccine.

“While the American Academy of Pediatrics and the CDC doesn’t recommend that vaccine this year … we want to make sure that people know that there’s plenty of vaccine out there.” said Dr. Joseph Bresee, chief of the Epidemiology and Prevention Branch of the CDC.

Egg allergies

Another new recommendation affects people with egg allergies.

In the past, people with egg allergies had to abide by special guidelines to get the flu shot. This included being monitored for any signs of allergic reaction up to 30 minutes after being vaccinated. This is because of the way the vaccine is created.

“Flu vaccines are one of the few remaining vaccines that are produced in eggs.” Bresee told Healthline. “We put the virus into eggs, they grow up in eggs, and then we purify them from there.”

This purification process is meant to remove all egg proteins from the virus strains used in the vaccine. But there were concerns that some egg proteins would survive the process.

Researchers were concerned that this could cause a dangerous — or even deadly — allergic reaction in people with egg allergies.

“It turns out, as the years went by and more and more evidence was created, that the risk of serious allergic reaction in people with egg allergy is really, really small.” said Bresee

Now, the CDC recommends that people whose egg allergies cause life-threatening reactions receive their vaccines in a facility with emergency medical equipment.

People who have only experienced hives when exposed to egg proteins can get the flu shot without any extra considerations.

Types of vaccines

There are three types of flu viruses. They are known as A, B, and C.

Types A and B are responsible for the epidemics that occur during the flu season, so flu vaccines are made to protect against the strains of these viruses that are currently circulating.

Flu vaccines fall into two different types: trivalent and quadrivalent.

Trivalent vaccines contain three dead virus strains: the circulating versions of the A viruses known as H1N1 and H3N2, and the most prevalent version of the B virus.

The quadrivalent virus contains four dead virus strains: the two A strains and two components of virus B.

However, current research doesn’t show any clear benefit to getting the quadrivalent vaccine instead of the trivalent vaccine. So the CDC doesn’t recommend one vaccine over the other.

“We believe all the vaccines are good and [you should] get whichever one you can, quickly.” Bresee said.

What is the flu?

Flu, or influenza, is a virus that can cause mild to serious illness.

In severe cases, the virus can cause hospitalization or even death.

Pregnant women, young children, and older adults are considered high-risk groups for experiencing flu complications.

The flu season begins in October and can run as late as May, according to the CDC. It’s recommended that you get a flu shot every October. But as long as the virus is still circulating, it’s never too late to get vaccinated.

The CDC recommends that everyone gets a flu shot, starting at 6 months of age. Children younger than 6 months will be protected from the virus through their mother’s breast milk if she is vaccinated.

Low vaccination rates

People between the ages of 5 and 65 — excluding pregnant woman — are considered low-risk for flu complications. But that doesn’t mean they should skip the annual shot, although they often do.

“I think people are underestimating how severe the flu can be.” Bresee.

There are reasons people who are low-risk should get the vaccine. It lowers their chances of getting the flu, and also prevents them from passing the virus on to a person that is considered high-risk.

But most importantly, being low-risk for flu complications doesn’t mean there’s no risk.

“Every year we have hospitalizations and deaths in this country, lots of them, that are among this group that don’t have any identifiable risk factors.” Bresee said

Getting vaccinated can be inconvenient for otherwise healthy people, but it’s still important.

“I think people need to realize that a short stop in a doctor’s office or a pharmacy for a vaccine can really save lives,” Bresee says. “Even in one of the people who don’t have risk factors.”