Get set for 2020's mega-campaign against the flu amid the COVID-19 pandemic:immunization drives in the parking lots of churches and supermarkets, curbside inoculations outside doctors' offices, socially distanced vaccine appointments held indoors, with breaks in between for disinfecting.

These are just some of the ways heath providers say they will give tens of millions of flu shots this fall — arguably the most important U.S. effort to prevent influenza's spread among Americans in a century.

Flu shots will be in stock at doctors' offices, pharmacies and supermarkets by early September. And though what's normally thought of as flu season in North Americadoesn't really begin until October and peaks between December and February, because of changes wrought by COVID-19, now is the time to start thinking about when, how and where you'll get immunized against the fluthis year.

"If you usually get the shot at the office but you're working from home, for example, you'll need a new plan, says Lori Uscher-Pines, a senior policy researcher with the Rand Corp. "And if you usually drop in to the pharmacy or the supermarket for your shot while you're out and about anyway, you'll need a new plan this year if, these days, you're just not 'out and about.' "

But do make a plan."No year is a good year to get the flu, but this year — with COVID-19 also raging — it's especially bad," says Mark Thompson, an epidemiologist in the Influenza Division at the Centers for Disease Control and Prevention.

"People who can avoid the flu will help reduce the burden on a U.S. health care system already overwhelmed by COVID-19," Thompson says.

Emergency rooms and urgent care clinics are often flooded with flu patients during winter months, he explains. So getting a flu shot can help prevent those visits — and thereby prevent the co-mingling of flu patients and COVID-19 patients, who can infect each other and spread their viruses to other ER patients.

"This year, more than ever, we're trying to get out the message that flu is no benign disease and you should do everything you can to prevent it," says L.J Tan, the chief strategy officer at the Immunization Action Coalition, a nonprofit group in St. Paul, Minn., that provides educational information for physicians and consumers on immunization. "In particular, get your flu vaccine. Take flu off the table."

In most years, some who get the flu would reasonablychoose to ride it out, feeling miserable for a week or so, or even shorten the illness by taking one of several prescription drugs approved to treat the illness, says Dr. Steven Pergam, an associate professor in the Vaccine and Infectious Disease Division at the Fred Hutchinson Cancer Research Center in Seattle.

But this year, "even people who never see a doctor for the flu might be prompted to book an appointment or head for the ER if they feel flu-like symptoms coming on," Pergam says.

That's because the flu and COVID-19 can share many (though not all) symptoms, including fever, chills, cough, sore throat, muscle or body aches, headaches and fatigue. Loss of taste and smell, which can happen with COVID-19, does not occur with the flu.

The flu is dangerous in its own right, hospitalizing and killing tens of thousands of people each year and sidelining millions more for days to weeks.

"And even if you might only have a few days of feeling poorly," Pergam says, "transmitting the flu to babies, older people and people with compromised immune systems risks severe illness or death for them."

Public health experts are also concerned about people having both the flu and COVID-19 at the same time. "We don't know yet whether that could compound either illness, but why take the risk?" says Dr. Ashish Jha, director of the Harvard Global Health Institute.

Preliminary CDC data for the 2019-2020 flu season, which ended in May, found the flu to be a factor in at least 18 million visits to health providers in the U.S., 410,000 hospitalizations and as many as 64,000 deaths.

Still, of all Americans eligible for a flu shot (that's nearly everyone over 6 months old), more than half don't get immunized in a typical year, according to CDC data. Among the reasons people give: worry about side effects (serious ones are very rare), worry that the shot will give them the flu (it won't), a belief that the flu isn't all that serious (it can cause severe illness and death) and an aversion to vaccines in general.

The flu vaccine — whether given via a shot or a nasal spray — isn't perfect. It's designed toward the end of each flu season — February for the Northern Hemisphere and September for the Southern Hemisphere — based on the four most prevalent strains of the flu circulating at each time. The expectation of those designing the vaccine, often right, is that those will be the most common strains that people in each hemisphere will face in the following flu seasons.

The Food and Drug Administration has final say on what the composition of the flu vaccine will be, and then it's made by private manufacturers during the spring and summer — generally ready for U.S. consumers by September.

But strains can mutate after the recipe is finalized (the flu virus is more changeable, genetically, than many other viruses), sometimes making the vaccine less effective. Last year, the U.S. flu vaccine was about 40% effective on average — that's defined by the CDC as reducing the chances by 40% that someone exposed to the virus had symptoms severe enough to visit a doctor or hospital.

"That's about the effectiveness rate we have many years and one reason people decide not to get the vaccine," Tan says.

"But that's a mistake on their part," he adds. "If you get a flu shot and then get the flu, you may be less likely to get a severe case. That could make it less likely you'll head to the doctor or the ER — just when they're filled with COVID-19 patients."

Most years, vaccine firms make about 170 million doses of the flu vaccine and at least a few million doses go unused, says Tan. For the 2020-2021 flu season, close to 190 million doses were produced, according to the CDC, including 7 million purchased by the agency for distribution to local health departments.

"That's the largest number of doses ever produced," says Tan, and manufacturers say more could be produced if there's even more demand.

While manufacturers might currently have the capacity to make additional doses of the flu vaccine, if more is needed during the flu season, once COVID-19 vaccines are potentially approved, some producers of flu shots could be competing for supplies as companies work to ramp up billions of doses against the coronavirus, says Harvard's Jha.

"Given what will be needed to make and administer a COVID-19 vaccine along with all other vaccines currently given, physicians, manufacturers and public health specialists are currently in discussion about the needed supplies and distribution," Jha says.

In light of the COVID-19 pandemic, many health organizations, including the CDC and the American Medical Association, are working on public awareness campaigns to be unleashed in September to prompt people to get the flu shot early.

In a recent survey conducted by , an advocacy group made up of people with a family member who became severely ill or died from the flu, over 40% of those polled did not believe it is important to get a flu vaccine this fall so they can stay healthy and preserve the health care system. That's 40% of Americans making a big mistake, say infectious disease specialists.

"We must plan now for a coordinated, season-long flu vaccination public outreach campaign that targets all, but especially communities with low vaccination rates — younger adults, African Americans and Hispanics," says Tom Daschle, a former Senate majority leader and the head of , which advocates for increased funding for anti-flu efforts. "This will require federal funding for programs designed to increase awareness of and access to flu vaccine as well as expand the number of licensed health care professionals who are able to administer vaccines."

The Coalition to Stop Flu is lobbying Congress for an increase of $300 million in support for the flu vaccine effort this year, possibly to be included in the next coronavirus emergency supplemental appropriations package. The funding would be used by the CDC for a public outreach media campaign and enhanced federal, state and local public health operations.

Dr. Susan R. Bailey, an immunologist, allergist and president of the AMA, has another message for patients and their doctors: "It's vital that patients are not permitted to opt out of vaccines for nonmedical reasons."

For that matter, even some of the medical reasons that exempt some patients from certain vaccines don't hold water when it comes to the current types of flu shot, says Bailey. For example, though the standard flu vaccine is indeed made in eggs, she says, even most people allergic to eggs can get the shot with no side effects, or they can opt for a flu vaccine that is not grown in eggs. Consult your doctor for specifics, she says.

A few other messages from the AMA president:

Pharmacies and doctors' offices are trying to be as creative as possible to allay the fears some people have expressed that they could catch the coronavirus while waiting in line for a flu shot. Chris Krese, spokesman for the National Association of Chain Drug Stores, says proposed plans by member pharmacies in his association include the following:

Spectrum Health, a health system serving hundreds of thousands of people in the Midwest, will be encouraging its patients to make an appointment this fall to have a health provider meet them curbside for the vaccination, or just drop by and call the clinic on arrival for a flu immunization outside; staff will be standing by.

Kaiser Permanente in Northern California is planning drive-through flu clinics for all days of the week, at least through late fall, that will permit patients to stick one arm out the car window for an immunizing jab. Meanwhile, patients coming inside the Kaiser clinics for any health reason will be offered a vaccination too.

And because outdoors is safer than indoors during this year of COVID-19, physicians who run One Medical, a nationwide primary care practice, say they hope to set up a number of outdoor flu clinics in addition to inside options.

The AMA's Bailey recommends reaching out to your doctor's office staff or website, or to the supermarket or pharmacy you're considering for the shot, to find out everything you need to know about signing up in advance or about the locations of outdoor vaccine clinics.

Rand's Uscher-Pines suggests taking everyone in the family for a flu immunization at the same time, "so no one gets left without." Parents of young children might check with the pediatrician's office, says Uscher-Pines, to see if the office will vaccinate the adults as well.

By Sept. 1, calling 211 or 311 should get you information on flu vaccine clinics in your area, including many hosted by local public health departments that won't charge a fee.

Also, flu vaccines are generally free for anyone with Medicare Part B, employer health insurance or other insurance that conforms to the Affordable Care Act, as well as for many Medicaid beneficiaries. However, you may have to go to an in-network doctor or pharmacy to get the free vaccine, says Cheryl Fish-Parcham, director of access initiatives at .

The CDC's website has a flu shot locator that will be operational by Sept. 1, but you may have to contact each location directly for social distancing details, such as which entrance to use.

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