Throughout the COVID-19 pandemic, the US has shown its lessening interest in mitigating the more manageable virus, influenza. Is there a chance to change course?
One of the first commissioned influenza (flu) vaccine trials was conducted in 8000 psychiatric patients from a pair of Michigan hospitals in 1942.
It was unconventional, to say the least.
A University of Michigan School of Public Health research team, led by Thomas Francis Jr., MD, and including then-fellow Jonas Salk, MD, was funded by the US Army during World War II to lead Francis’ longtime work in vaccinology toward a prophylaxis that could aide US soldiers overseas.
The team’s influenza vaccine was administered in a double-blind, placebo-controlled trial to tens of thousands of Army Specialized Training Program participants in 1943-44; the vaccine’s efficacy was so significant that it was ordered for administration in every member of the US Army in 1945.
But it was actually just years prior that Francis, Salk, and colleagues dosed their vaccine in institutionalized patients—before exposing 100 of their patients to the flu itself, to accelerate the time to observing vaccine efficacy.
Aside from this story serving as yet another anecdote of less-than-ideal values underlying a significant moment in history, it contextualizes how desperate the nation was for an answer to influenza.
The country was sending troops to Europe for the second world war in 30 years, and fears learned from the first informed their new measures. The rampant and devastating spread of the 1918 flu pandemic through US camps in World War I was as remembered as the Western front, or mustard gas. Defenses had to be prepared to mitigate all that they faced.
Francis, a young man during the 1918 pandemic, did not need reminder of what was at stake when assessing flu vaccines in the first patients—not only for the military, but for society. A pandemic which can kill millions, affect billions, without warning or discrimination, like the one he lived through, is worth a comparably greater amount of risk to resolve than other medical matters.
The memory of the first great modern pandemic does not persist in the conscience of the public in 2020—and neither does the acknowledgement of influenza as a threatening, yet preventable disease.
In responding to its own pandemic this year, this era has shown an indifference, if not disdain, for matters regarding the flu.
A failure to respond
The writing has been on the wall for months now. Experts have forewarned since the summer what an uncontrolled coronavirus 2019 (COVID-19) pandemic could look like in the winter months. Especially, they stressed, with the combined effects of an unchecked flu season: “twindemic” was a popular term for the coinciding events.
But seeing as the pandemic’s first vaccines were still progressing through phase 3 trials, all a person could add to their practice of social distancing and mask-wearing was a flu vaccination, to mitigate the possible combined effects of COVID-19 and the flu during the 2020-21 season.
The healthcare system played a part. Vaccine manufacturers including AstraZeneca produced more than 25% of its annual flu doses this year. Chain pharmacies Walgreen’s and CVS began running television ad campaigns for flu shots in mid-August. And experts, already overwhelmed with COVID-19 messaging demands, returned to the longtime challenge of vaccine advocacy and education for a longtime-hesitant population.
“More than ever this year, reducing respiratory illnesses through influenza vaccination is an important piece to public health,” hospital epidemiologist and infection preventist Saskia Popescu, PhD, MPH, told sister publication Contagion®. “Patients presenting with nonspecific respiratory symptoms to already stressed health care systems will further strain supplies, staffing, and even testing capacity. If we can reduce that burden by even a little, we must.”
For all this preparedness leading into the most distressed flu season in modern history, little came from the population itself.
As of early November, just 49% of US adults have been vaccinated for this flu season, according to survey data from research institution NORC at the University of Chicago. Another 35% stated they have no intention of getting vaccinated.
Though the rate of self-reported vaccination is up 5 percentage points from NORC’s reported 2019 data—and the rate of the most at-risk age group of 60-plus years old is at a new high of 71%—investigators saw the same old lines explaining vaccine hesitancy in a vital portion of the US population.
More than half the respondents who did not plan to get the vaccine stated any of these reasons drove their decision:
“Unfortunately, I think there’s just a lot of people who don’t take any of these infectious diseases seriously at all, like they should,” Caroline Pearson, NORC senior vice president, told HCPLive®. “It’s disheartening.”
Among the listed majority reasons for avoiding the flu vaccine, a couple are misinformed, one is outright unfactual, and several are inherently selfish to the idea that vaccination better protects households and communities, not just the patient.
On the matter of so many persons still believing they could actually become ill with the flu from a vaccine, Pearson shared a frustration felt by many public health experts: how do you explain away a popular, baseless fear?
The local and solicited effects of an annual flu vaccination, including fatigue, injection site pain, and mild feverish symptoms, are enough to perpetuate this growing myth—or, at least, support its possibility among the population.
“The reality is it doesn’t really matter whether people think they have the flu or that they just have bad side effects,” Pearson said. “People don’t want to feel unwell. And while they really don’t want to get sick, they don’t want to make themselves feel unwell all the same.”
What's more, there continues to be a lack of understanding on how the flu vaccine benefits persons beyond overall protection from the virus. Pearson said people "absolutely do not understand" the benefit of the vaccine for reduced risk of hospitalization or severe illness from the flu—only the false notion that it should provide absolutely perfect immunity from infection.
"Folks really don’t seem to appreciate that advice," Pearson said. "The challenge is that nobody thinks that the worst outcome is going to happen to them."
The matter of COVID-19, which so many legislators and public health officials banked on serving as a rallying point for flu vaccination, may have actually worsened matters. Only about 1 in 5 flu shot dissenters stated they avoided in-person vaccination due to pandemic-driven social distancing. Many others, Pearson said, may be refraining from vaccination to make a point that’s tied into COVID-19 debates.
“Much like many aspects of our society, everybody’s preconceived notions hardened this year as the stakes went higher,” Pearson said.
In some cases this year, flu was perceived as less a serious issue in public health, and more a comparative point of debate in the pandemic.
Very early into the pandemic’s beginning, most of what was understood about SARS-CoV-2 was that it is a respiratory infection spread commonly through droplet and airborne transmission and presented in flu-like symptoms. Naturally, the public and even leadership linked the 2 diseases together, mostly as means of identifying and knowing how to mitigate the mysterious virus.
What was not intended from such a likening is what occurred: a comparison of mortality rates, illness duration, and age- and health-based risk assessments suddenly downplaying the overall threat of COVID-19.
Indeed, the flu-coronavirus comparative conversation grew so loud in April and May of this year that academics and public health officials alike began to combat misinformation. A viewpoint published in JAMA Internal Medicine in mid-May simply evidenced the 20-fold mean increased risk of mortality with COVID-19 versus influenza—based on CDC data which did not even represent the current peak of overall US mortality associated with the pandemic.
“Although officials may say that SARS-CoV-2 is ‘just another flu,’ this is not true,” investigators stressed. “Our analysis suggests that comparisons between SARS-CoV-2 mortality and seasonal influenza mortality must be made using an apples-to-apples comparison, not an apples-to-oranges comparison. Doing so better demonstrates the true threat to public health from COVID-19.”
This tie-in of COVID-19 with the flu not only falsely downplayed the threat of the pandemic at its very beginning, but it allowed for influenza to become likened to a non-threatening respiratory virus—something only slightly worse than a common cold.
Meanwhile, the US has just surpassed 300,000 deaths associated with COVID-19, and majority flu vaccination among adults has not been assured.
“It’s a lot of misinformation, a lot of people minimizing risks and not understanding the data, and obviously that has come back to haunt us,” Pearson said.
An impressionable future
One year after public flu vaccination began, Francis was granted the US Medal of Freedom. Ten years later, Salk’s polio vaccine would reach the public and help advance the field of vaccinology to new heights and capabilities.
Just 4 days ago, Pfizer and BioNTech were granted Emergency Use Authorization (EUA) for its mRNA vaccine BNT162b2, as the first indicated vaccine for preventing COVID-19 in the US. Vaccination of healthcare workers and long-term care facility residents began this week, and hopes to vaccinate millions more Americans will be met in 2021.
The story of COVID-19 vaccine development and distribution will be remembered as the greatest story in medicine to occur in 2020. It may even be likened to the historic work of Francis and Salk one day.
But the contrasted reception to the flu vaccine—an already known, already available product that could have lessened the need for these miraculous COVID-19 innovations—represents the year’s trademark shortcoming in public health awareness and prioritization.
The continued struggle from the US to truly adopt annual influenza prevention strategies, 75 years into the availability of a vaccine, does not appear likely to improve in coming decades. As NORC observed, 51% of Americans aged 18-29 years old did not plan to get vaccinated this year.
Another 43% of adults with children under the age of 18 years old living in their home stated they did not intend to vaccinate their children.
Flu vaccination rates remain among the worst of those recommended for children and young adults, Pearson explained, largely due to lessened mortality/morbidity risks, a growing chasm between the US healthcare system and young adults, and the guidance of vaccine-hesitant parents.
Especially given the impeding distribution of new vaccines, there is still an opportunity to learn lessons from COVID-19 in public health preparedness, physician-patient communication, and vaccine misinformation.
All 3 of these factors have contributed to the ongoing challenge to prioritize flu prevention, and improving on them in the next generation of would-be patients could set a precedent in vaccination unmatched in decades.