The world is eagerly awaiting the creation of a Covid-19 vaccine, which is happening at a record-setting pace, but it's not the only vaccine that may determine how pandemic-centered lives unfold this winter.
There's another vaccine that will play a key role. It already exists.
The flu vaccine feels pedestrian compared to the hopes pinned on the Covid-19 vaccine. Still, getting that vaccine could go a long way to keeping the costs of the Covid-19 pandemic under control, explains Libby Richards, an associate professor at Purdue University's School of Nursing.
"Unfortunately, Covid-19 will still be circulating during flu season, which makes getting a flu vaccine more important than ever — especially as schools and our economy continue to re-open," Richards tells Inverse.
Historically, our track record on the flu vaccine hasn't been great. The CDC estimates that only 45.3 percent of adults received the flu vaccine during the 2018-2019 flu season, which was up about 8 percent from the previous year.
Richards adds that this year Covid-19 complicates the situation; it's already "led to decreased use of preventative healthcare services, including vaccines."
If the flu vaccine is traditionally around 60 percent effective (the flu vaccine varies in effectiveness each year depending on strain — last year it was about 45 percent effective, per the CDC), we would need to have about 83 percent of the population vaccinated to achieve herd immunity. That's the stage when enough people are immune to a disease, that it's rare for even unvaccinated people to get sick.
Getting as close as possible this year to that percentage could have lasting impacts on the ability of the healthcare system to fight Covid-19.
"Our healthcare system is already stretched thin; I think if it gets stretched much thinner, we could be at a breaking point," Richards says.
Why getting the flu vaccine is important:
Flu season usually runs from October to April each year. It varies in severity and its regularity and normalization obscure how devastating the flu can really be.
The CDC can only estimate the true burden of the flu because of reporting delays or consequences that go unreported. But during the 2019-2020 flu season, the agency estimated that the flu accounted for between 18 million and 26 million medical visits, between 410,000 and 740,000 hospitalizations, and between 24,000 and 62,000 deaths. Those numbers are adjusted to account for the fact that more people may have been tested for the flu fearing those symptoms may have actually been coronavirus.
These statistics don't exist to compare coronavirus to the flu, rather they underscore the fact that when the two illnesses meet, the compounded effects could be a "twindemic" – a phrase popularized in an August 16 New York Times story.
A twindemic might emerge because of the strain that yet another respiratory illness might put on our healthcare system, Richards explains. Getting the flu vaccine could reduce the number of severe flu cases that happen this year – and these severe cases require the same lifesaving equipment that is used to fight severe Covid-19, she says.
"We have all heard the Covid-19 stories of ICUs filled beyond capacity and shortages of equipment such as ventilators. If we add a bad flu season to that — we won’t be able to handle it," she says.
What about Australia? – The Northern Hemisphere often turns to Australia as a forecast of what our flu season might look like. But even there we're left with some huge unanswered questions, even though that country has already lived through a flu season combined with Covid-19.
Australia actually had an unusually mild flu season during 2019-2020. While cases in January through Mid-March were higher than every season since 2009 (save for 2019), cases plummeted as March transitioned to April.
The Australian Government Department of Health suggests that measures intended to slow Covid-19 like social distancing and other "health-seeking behavior" likely helped stem the spread of the flu. Australia also imposed a strict lockdown in March that included limiting social gatherings to two people and bans on international travel alongside other measures (it has since strengthened those measures as cases began to resurge).
Australia also saw higher-than-usual rates of flu vaccination in 2020 compared to previous years. Between March 1 and April 19, 2.1 million flu vaccines were administered in Australia compared to 624,000 in 2019, the Australian Department of Health reported.
The United States has yet to impose such tight restrictions, like limiting distance people can travel from their homes, even as cases surged in the summer. We should take care to not take Australia's experience as a forecast of what ours could be, says Richardson.
"In the US we have been less consistent with these preventive measures so I think it is unlikely we will see the same mild flu season," she says.
What is the best time of year to get a flu shot?
The CDC already expects to have 20 million more doses of the flu vaccine on hand this year compared to the 2019-2020 flu season.
Richards says September is a "great time" to start thinking about the flu vaccine and is when she chooses to get vaccinated. That said, getting a vaccine too early could potentially lead to reduced immunity later in the winter. Regardless, you definitely want to aim to get a vaccine before the flu starts circulating.
"It takes about two weeks for the body to develop immunity from the vaccine and we tend to see flu cases starting to increase in October so I always try to get myself and my family vaccinated in September," Richard says.
In September, Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases, said he waits until "the middle and end of October."
It may feel a bit nerve-wracking to think about walking into a clinic to get a flu vaccine during a pandemic. To make things a bit easier, Richards suggests taking basic precautions like wearing a mask, and making sure to sanitize your hands before you go into the doctor's office and after you leave.
She says that it's worth making the trip and that getting coronavirus from the clinic is "very unlikely" especially since healthcare providers take extra precautions like wiping surfaces down between patients.
It's far more important to ensure that there's less disease going around in the outside world. And taking influenza off the table (as much as is possible) could be a huge step towards keeping this winter under control.
"Getting vaccinated isn't just about personal health, Richards explains. "It also protects the health of your friends, family, and community."
Editor's Note: This story has been updated to include comments from Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases.