September 3, 2019
The flu might seem like the same old virus every year that brings stuffy noses, sore throats, achiness, and fever and makes us want to spend the whole day (or week!) in bed. But soon, we might be able to kick those annoying symptoms to the curb. We’ll explore how this year’s flu season might look based on Australia’s 2019 flu season, if pandemics should be a concern, and what vaccine scientists are doing today to create a healthier tomorrow.
Australia’s Flu Season: What it Could Mean for the US
US health experts study Australia’s flu season because their fall and winter coincide with our spring and summer. That means their flu season occurs right before ours – so it helps us better predict what we might expect this fall. Australia’s flu season started early this year, beginning in March 2019, which is the start of their fall season. This could mean our flu season starts earlier, too, with cases peaking in December rather than February. While there is not a clear reason for the early start to Australia's flu season, last year’s mild outbreak prompted less people to get their flu shot, meaning they might be more susceptible to infection this year. Some experts believe that an early start may mean an early finish, too. Health officials in the US will continue to track the number of hospitalized cases and reported influenza-like illnesses, to see if this prediction is true1. An influenza-like illness is diagnosed when a person has developed a contagious respiratory infection along with a cough and a fever over 100 degrees.
Though the number of confirmed flu cases in Australia—195,428 as of the end of July— is higher than some years, this number still falls short compared to the 251,160 confirmed cases in 20172, which was one of the most severe seasons we've seen in years. While it’s too early to know how many confirmed cases Australia will have by the year’s end, most experts agree that the current data does not indicate a flu season as severe as 2017’s.
Though Australia’s 2019’s flu season isn’t the worst we’ve seen, one reason that this year’s flu season may be more severe than last year’s is that there are three strains of the virus that are currently circulating: two kinds of influenza A and one of influenza B. Influenza A can be spread through both humans and animals while influenza B is just spread by humans. The best way to prevent the flu is to receive an annual flu shot that is created to protect against that year’s predicted strains of the virus. It typically takes two weeks for the vaccine to start working, so getting your vaccine early can help protect you during the peak of flu season.
Is Another Pandemic in our Future?
A flu pandemic is a global outbreak of a new influenza A virus. Often, pandemics occur when people are exposed to a new type of the flu virus they may not be immune to, allowing the virus to quickly spread. Though some flu seasons are more severe than others, actual pandemics are rare, with only four in the United States over the past 100 years (that's a pretty good track record!) Often, these strains of the virus are transmitted from animals, such as wild birds and pigs (i.e. avian and swine flu).
The last major pandemic in the US was the 2009 H1N1 (swine flu) outbreak. This pandemic started in the United States and affected mostly children and young to middle-aged adults, who did not have immunity to this specific type of influenza. On the other hand, 1/3 of older Americans had immunity due to previous exposure. Since the type of virus was very different from the usual seasonal flu, vaccines were not as effective against it for the younger population. As technology continues to improve, health groups such as the World Health Organization (WHO) and the Center for Disease Control (CDC) are equipped with preventative measures to lessen the effects of another such pandemic. Though an outbreak can occur at any time, careful monitoring and improved testing, diagnostics, and tracking have significantly lessened the impact of pandemics over the past 100 years and will continue to inform and improve the effectiveness of yearly vaccines.
While it’s unlikely for another severe pandemic like the 1918 Spanish Influenza to occur, practicing good hygiene, staying away from those who are sick, and receiving an annual flu shot are three simple ways to prevent the spread of flu.
Defeating the Flu—Once and For All
Soon, your annual flu shot may be a bit different. Scientists have been developing a universal influenza vaccine with the goal to treat all forms of the virus, including those that cause pandemics (go science!).
In April 2019, the National Institute of Health (NIH) began its first clinical trial of a universal influenza vaccine. Developed by scientists at the National Institute of Allergy and Infectious Diseases, the vaccine is designed to help peoples’ immune systems fight against many types of the virus. Influenza has two kinds of strains, influenza A and influenza B, and each strain has subtypes. A subtype is determined by the type of protein found on the surface of the virus—for example, the subtype H1N1. The experimental vaccine, called H1ssF_3928, was first tested in mice and ferrets, where it successfully protected the animals against more than one type of the virus.
The first-round of clinical trials has a similar objective: to see if the vaccine can help the immune system create antibodies, or special proteins that help remove harmful substances from the body, in humans. Scientists hope to learn how age and potential previous exposure to influenza affect the level of antibodies created. While the results of the trial won’t come out until 2020, they could change how future flu vaccines are created and potentially eliminate the need for yearly flu shots. A second clinical trial in the future will test another vaccine that may protect against the other main strain of seasonal flu.
The future may be unpredictable, but history and emerging trends can teach us a lot about the flu. What we do know is that practicing good hygiene and getting your annual flu shots are two small steps that can go a long way in staying healthy—both today and tomorrow.
References:
1 Australian Government Department of Health: Australian Influenza Surveillance Report No. 5 – 17 June to 30 June 2019. Figures 2 and 6. Last updated July 5, 2019. Accessed July 15, 2019.
2 National Notifiable Diseases Surveillance System: Number of notifications of Influenza (laboratory-confirmed), Australia, in the period of 1991 to 2018 and year-to-date notifications for 2019. Last updated July 16, 2019. Accessed July 15, 2019.
3 National Institutes of Health: NIH begins first-in-human trial of a universal influenza vaccine candidate. Last updated April 3, 2019. Accessed July 12, 2019.