Many people preventing from flu

Reducing the Unpredictable Risks of the Predictable Flu Season

Reducing the Unpredictable Risks of the Predictable Flu Season

Dr Rosalind Hollingsworth, Global Medical Affairs Lead, Influenza Vaccines, Sanofi Pasteur.

It’s that time of year again: the kids have gone back to school, the leaves are changing color, and the pumpkin spice lattes have invaded our coffee shops. Fall is upon us, and that also means the flu season will soon begin across the Northern Hemisphere.

Unlike other seasonal events, though, the flu can be much more unpredictable.

Most people know that when they get sick with the flu, they will probably have a very miserable few days in bed – and most people will recover in less than two weeks.  We also know that some people are at high risk for severe influenza infections and complications, such as pneumonia, including young children, the elderly, pregnant women, and those with chronic health conditions, like asthma, diabetes, or heart disease, to name a few.

But no one can predict precisely who will suffer the worst consequences of flu or what those consequences will be.  Indeed, otherwise active, healthy adults may be vulnerable to the flu. Even in previously healthy adults, severe cardiac problems like strokes and heart attacks spike during flu season, triggered by flu infections.1

The flu’s predictable unpredictability is what makes vaccination so important. The WHO, US CDC, and other national health authorities around the world recommend vaccination as simply the best way to help prevent the flu and reduce the risks of serious complications.

Influenza vaccine effectiveness can vary from year to year, and is influenced by a person’s age, health status, and by the unpredictability of influenza virus strain circulation (four influenza viruses can circulate each season, but which will dominate is difficult to predict, can vary between countries, between seasons, and even within a single season). Despite this variability, vaccination can help to stop you from becoming sick with the illness, can help reduce the severity of flu in some people who are vaccinated but still get sick, and it can help reduce your risk of being hospitalized or dying from the flu. Vaccination can also help prevent some of the serious complications of influenza. In a study conducted among adults 65 years of age and older, the vast majority of whom were not considered particularly at risk for severe flu complications, flu vaccination was associated with significant reductions in the risk of dying from stroke by 65%, and heart disease by 22%.2

What’s more, in many countries, people recommended for vaccination receive their influenza vaccine through government health care programs or private insurance coverage: health care payers around the world recommend vaccination to help prevent complications that can lead to more costly care like hospital stays.

But even without insurance coverage, for perhaps only the cost of a few pumpkin spice lattés, most people can reduce their risks of influenza this year.

I’m proud to work with a team that develops and delivers millions of vaccines each season so that those who want to be vaccinated can be. But there’s much more that can be done. We are working hard medically and scientifically to develop better influenza vaccines, and we are also considering how new manufacturing technologies might help us achieve this aim. In the longer term, we have our sights set on a vaccine that will cover more strains of the influenza virus, beyond the three or four already included in current vaccines. This could mean that the influenza vaccine would not need to be changed each year to ensure a match to circulating influenza strains and could potentially be given just once to provide protection over several influenza seasons.

But right away, even this fall, we can all do more. We can continue to help raise awareness across our communities about the dangers of influenza and the value of vaccination in reducing those risks.

Personally, I’m concerned for all who may encounter the flu this season, but I do think particularly of many seniors, like my own mother, who are generally healthy and doing well, enjoying their retirement and grandchildren. For them, getting their annual influenza vaccination puts the odds in their favor - they are more likely to avoid the flu but more importantly, fend off the longer-term, sometimes life altering consequences of this unpredictable virus.



  1. Kwong, Jeffrey C. et al N Engl J Med 2018;378:345-53. DOI: 10.1056/NEJMoa1702090
  2. Wang CS, et al. Vaccine. 2007;25(7):1196-1203