A new vaccination drive kicked off last week, but the effort wasn’t intended to encourage inoculation with the three available COVID-19 shots. The purpose of the U.S. Food and Drug Administration’s weeklong vaccination campaign was to boost the number of people receiving a flu shot this year. 

Flu activity peaks from December to February, the FDA explains, but it can take about two weeks for the body to develop an antibody response. So the agency’s social media campaign was designed to remind Americans that it’s an ideal time to roll up their sleeves again.

Some 44% of adults have gotten a flu shot, according to the Centers for Disease Control and Prevention flu dashboard, versus the 60% of Americans who are fully vaccinated against COVID. Among children, this season’s vaccination pace lags the 2020-2021 campaign by 6.9 percentage points (39.8% versus 46.7%).

The effort could use a jolt, and quickly. The annual FDA campaign comes amid warnings from health authorities of a dangerous one-two punch in the making: COVID and flu in the air simultaneously.

While the Delta variant continues to wreak havoc, reports suggest Omicron may soon start to gain traction in the U.S., just as it has abroad. As researchers examine the question of whether or not the new strain will supplant Delta, COVID outbreaks are appearing in certain regions of the country – and a more virulent virus could exacerbate those flare-ups.

Meanwhile, after hibernating since March of 2020, the flu appears to be waking up. While flu activity is currently low nationwide, signs point to a potentially tough winter. The CDC recently warned healthcare providers of early circulation of a strain of flu known as influenza A(H3N2). 

When influenza A held sway as the predominant strain in previous seasons, more hospitalizations and deaths occurred among people 65 and older. A bad flu season paired with another COVID surge could put a strain on already short-staffed hospitals, public health officials worry.

So far, most of the flu cases have been in young people, the CDC said in a weekly update last week. Flu markers, like outpatient visits for flu-like illness, are still below baseline, but activity is slowly increasing.

The Georgia Department of Health, for one, shows 59% more cases of flu this year versus last year, with kids four and under the most heavily affected group. They’re coming into doctors’ offices with high fevers, body aches, coughs and sore throats. 

While there were no other health holidays last week, the FDA’s flu campaign nevertheless faces some attentional headwinds. (No, we’re not talking about competing topics like beer, brownies and microwave ovens, all of which appeared on the National Day Calendar recently.)

Millions have been spent on COVID-19 pro-vaccination messaging, with PSAs and other public health advertising blanketing airwaves. The news cycle, meanwhile, has been dominated by Omicron and whether it evades the protection afforded by the COVID-19 vaccines. Pfizer and BioNTech said early data suggest that their booster can offer enhanced protection against the new variant, while the initial two-dose regimen may still guard recipients from severe illness.

Amid the all-COVID-all-the-time atmosphere, doctors are concerned about “vaccine fatigue” among people who have received a vaccine and booster but may skip their annual flu shot. The concern is well-founded: More than one-fourth of adults (27.6%) say they are not planning to receive the flu shot, per CDC data.

The flu jab gets a bad rap for being far less effective than the COVID-19 shot, causing more side effects and preventing an illness that causes far fewer deaths. But facing the very real possibility of the confluence of influenza and COVID-19, this is not the year to skip flu inoculation, experts caution. 

“It’s very well described in the American literature that you can have dual infection,” one infectious diseases expert said. 

As to why we didn’t consider that an issue last year, it’s likely because there wasn’t much flu to go around. Last year’s flu season saw a mere 2,000 confirmed cases, compared to 39 million the year prior. 

Experts attributed this extraordinarily low rate to so many people taking basic safety measures against COVID-19, like masking and handwashing. But it’s possible that the low rate of flu cases in 2020-2021 might translate into fewer people having immunity to the flu strains circulating this winter. 

Paired with the easing of COVID-19 precautions and Americans starting to travel more for the holidays, that could mean a rough season for the flu.