Influenza is already out there and health officials urge people to get their flu shots in October

"We are starting to see some flu influenza activity and we would actually, yeah, recommend any time is a great time to get your flu shot," Minnesota Department of Public Health nurse Jessica Metzger says.

The severity of the strain that's circulating isn't yet known, but Metzger says influenza is nothing to mess with. Every year flu alone causes hundreds of thousands of hospitalizations in the U.S. and kills tens of thousands.

"Influenza, which we get in such a habit of calling it just the flu, can really take you out for anywhere from, you know, 7 to 10 days," Metzger explains. "It can really give you fevers, it can give you chills, body aches, fatigue."

Metzger says it's important to stay home if you're sick to avoid infecting others. She says the health department is also still recommending the COVID vaccine as well, which you can get at the same time as your flu shot.

Flu cases across the U.S. are inching upwards, even on the West Coast where San Francisco has reported its first death from the flu already.

Vaccination isn’t “a guarantee that we’re going to prevent illness." But just like the seat belt in your car, it decreases risk” of the worst outcomes. ABC News Medical Contributor Doctor Darien Sutton says it's not too early to get a flu shot.

"You want to get vaccinated before Halloween," says Sutton. "It takes about two weeks for the flu vaccine to take effect in your immune system to get that level of protection. And it's recommended for everyone above the age of six months. This is guided by global surveillance, expert review and supported by leading institutions like the American Medical Association."

Sutton says this is recommended for more than just people at a greater risk, with the vaccination helping stop serious flu-related health issues in all people.

"Now, we focus on the high risk older adults, young children, pregnant moms and those with underlying chronic conditions," he says. "The flu can be so much more than an inconvenience. The goal is to prevent complications like hospitalizations and deaths, which is why prevention and acting now is so important."

This year also saw a new health alert that's another option in trying to avoid the flu. Moderna's MRNA seasonal flu vaccine is now available for people 50 and older following FDA approval in August.

The new flu shot may expand to other age groups, after more research on younger people says Doctor Omer Awan, a physician and senior public health contributor for Forbes.

"A large trial showed that the MRNA shot was about 27% more effective than the standard flu shot," Awan explains. "It can be tailored and matched more appropriately to the circulating flu strains that are occurring, and that can provide potentially better protection against the flu."

He recommends you talk with your doctor about it as an option.

Fall vaccine advice usually comes from the Centers for Disease Control and Prevention and its independent advisory panel. But this year that panel, which influences state and insurance vaccine policies, is caught in a court battle and the CDC hasn’t updated its flu advice.

Now doctors’ groups are filling the gap: the American Academy of Pediatrics, American Academy of Family Physicians, American College of Obstetricians and Gynecologists, and the Infectious Diseases Society of America have posted vaccination guidelines for their patient populations plus the scientific evidence behind them.

Here’s what to know:

Just about everyone should get vaccinated against flu

Just about everybody starting at age 6 months needs flu vaccination, the medical societies agree. But flu is particularly dangerous for people 65 and older, pregnant women, young children and people of any age who have chronic health problems, including asthma, diabetes, heart disease and weak immune systems. The last two flu seasons brought unusually high numbers of child deaths, the vast majority of them in unvaccinated kids.

The vaccines don’t block all flu infections, but they do help prevent the worst outcomes, decreasing older adults’ hospitalizations by 31% last year, according to the Vaccine Integrity Project, a public health group based at the University of Minnesota.

Here’s how to pick from the multiple flu vaccine options

Three “enhanced” flu vaccines are designed to better protect seniors. The American Academy of Family Physicians urges them to choose one — “but do not delay your vaccination if that one’s not available,” said AAFP’s Dr. Sarah Nosal.

The Food and Drug Administration recently approved a new choice for people ages 50 and older, the first flu vaccine made with the same mRNA technology that was key to ending the COVID-19 pandemic. One study found Moderna’s mFlusiva was 27% more effective against symptomatic illness among 50- to 64-year-olds than a standard shot.

The shot-averse could choose a nasal spray, FluMist, if they’re ages 2 to 49 and meet other health criteria.

The latest on COVID-19 vaccines

COVID-19 shots once were recommended for just about everyone by federal health agencies, but like last year, the FDA has only formally approved them for higher-risk people — those ages 65 and older or younger people with at least one health condition that increases their risk.

Still, the family physicians recommend all adults get a COVID-19 vaccination, especially seniors and those with other risk factors. Adults 65 and older should get a fall dose and then a second dose six months later, as immunity wanes over time, Nosal said.

The American Academy of Pediatrics recommends a COVID-19 shot for all children ages 6 months to 23 months, and for older kids with high-risk conditions. It also supports vaccination for any child whose parent wishes it.

With millions of shots administered, there’s no evidence that coronavirus vaccination during pregnancy increases the risk of miscarriage or other problems, “so please get the vaccine,” said ACOG’s Dr. Christina Davidson.

Depending on age, people can choose a shot from Moderna, Pfizer, or the only non-mRNA version from Novavax and Sanofi.

Just like with flu vaccines, these shots are better at preventing severe disease than mild cases. The Vaccine Integrity Project said last fall’s COVID-19 shots cut the risk of hospitalization by 53% in seniors and slashed emergency room visits for very young children.

Common side effects for flu and COVID-19 vaccines are mild and temporary, such as sore arms, fatigue, headaches, muscle aches, and mild fever. They occurred somewhat more often with the new mFlusiva than with standard flu shots.

Here’s where you can get vaccinated

While pediatricians and some clinics offer both flu and coronavirus shots, they’re available for most ages through pharmacies. For example, Walgreens says it now offers both shots for ages 3 and older, no prescription needed.

Medicare covers the fall shots and most private health insurers say they plan to continue doing so through 2027. If you want to choose mFlusiva, the new Moderna flu option, make sure to double check that your insurance covers it.

When to get vaccinated

Flu experts say October is best, although vaccinations will remain available through the fall — just remember it can take two weeks for protection to kick in. COVID-19 cases rose in the late summer and usually do again around the winter holidays. Some experts say it’s also OK to time the coronavirus shot a few weeks ahead of an event you wouldn’t want to miss because of illness, like a special trip or get-together.

RSV is a nuisance for many, but it can be deadly for some

RSV, or respiratory syncytial virus, typically is a cold-like nuisance during the fall, winter and early spring. But it can be severe, even life-threatening, for infants and older adults.

The family physicians recommend a one-time vaccination for adults 75 and older, people 50 to 74 who are at increased risk, or younger people with weak immune systems.

It’s also recommended during late pregnancy to protect infants born during RSV season. Separately, the pediatricians recommend a vaccine-like medication for those infants whose moms weren’t vaccinated and some other high-risk babies.