Americans need to prioritize getting their influenza vaccine now, public health officials warned Thursday.

Why it matters: The seasonal flu combined with the coronavirus pandemic could lead to a "twindemic" with increased chances of co-infections and an overwhelmed health system. Because symptoms are similar and diagnostics aren't fast, people can best mitigate their risks with the flu shot plus social distancing and mask-wearing this fall and winter.

What's happening: "This is going to be a diagnostic area of confusion this entire winter season, what with these two viruses and other respiratory viruses that are out there," National Foundation for Infectious Diseases medical director William Schaffner said during a press briefing.

• NIAID director Anthony Fauci said, "It is always dangerous to get the wrong diagnosis ... that's one of the reasons we're underscoring the importance of making sure you can help eliminate at least one of them, or at least mitigate one of them, by vaccination."
• The good news: Similar behaviors are helpful in preventing both viruses, and if people get the flu shot and continue practicing measures like mask-wearing, social distancing and hand washing, the U.S. may see a mild flu season similar to the Southern Hemisphere, Fauci added.

By the numbers: The most-cited reason for participants to not get a vaccine, per an NFID survey out Thursday, continues to be disbelief in the shot's effectiveness — but this dropped from 51% last year to 34% this year, Schaffner said.

Between the lines: Many of the same people most vulnerable to serious complications of COVID-19, such as older adults and those with chronic health conditions, are also at risk for complications from the flu, including myocarditis, pneumonia, heart attacks and strokes.

• Cardiologist Federico M. Asch said flu vaccinations and pneumococcal vaccines have been shown to lower rates of cardiac arrest in people with heart disease, diabetes, COPD and asthma.
• Of concern are survey results showing 22% of people at high risk for flu-related complications said they were not planning to get vaccinated this season, said Asch, an associate professor of medicine at Georgetown University.

Health disparities — seen prominently in the pandemic — play a role with flu vaccinations as well, multiple health officials said.

• Black adults (61%) are more worried about co-infections than Hispanic (53%) and white adults (39%) — but nearly 62% of Black adults said they are either unsure about getting, or will not get, a flu vaccine this year, per the survey.
• "This disconnect is a big concern," said NFID president Patricia N. Whitley-Williams, citing multiple barriers to vaccination in communities, including unconscious bias, institutional racism, distrust of the health care system, and vaccine hesitancy.
• 65% of Hispanic and 59% of white adults plan to get flu shots this season.

Context: On Thursday the CDC issued preliminary estimates from the 2019–2020 flu season showing: 38 million illnesses, 18 million medical visits, 400,000 hospitalizations, and 22,000 flu deaths including 189 children.

• "More than half of these children were healthy — they had no pre-existing conditions," Whitley-Williams said, adding that vaccinations are estimated to reduce flu-associated deaths in children by 65%.
• The CDC also said they believe flu vaccines in 2019–2020 prevented roughly 7.5 million illnesses, 3.7 million medical visits, 105,000 hospitalizations, and 6,300 deaths.
• Vaccination rates last season rose to 48% in adults, but showed "significant disparities" as 55% white people got vaccines compared with no change for adult or children vaccination rates for Black people (at 46%) and Hispanics (at 47%).
• Only 44% of people with at least one chronic condition got the flu shot last season.

ICYMI: The CDC says there are four licensed antiviral drugs recommended this flu season: oral oseltamivir, inhaled zanamivir, intravenous peramivir, and oral baloxavir.

The bottom line: "The COVID-19 pandemic ... has underscored the importance of addressing myths and misconceptions about vaccine safety and advocacy in communities of color," Whitley-Williams said.

• "Now is the time for change. Now is the time for everyone to get a flu vaccine."

Go deeper:

• What's needed to prevent a COVID-flu nightmare
• Pandemic re-emphasizes need for universal flu vaccine
• The winter from hell