What is it?
Influenza A virus subtype H1N1 (a mouthful, I know!) is a type of flu virus responsible for a lot of damage over the years. Strains of H1N1 caused the 1918 Spanish flu pandemic, the 1977 Russian flu pandemic, and the recent 2009 swine flu pandemic. You have probably caught the flu once or twice in your life, as it is quite common and in fact, some strains of H1N1 are endemic in humans, causing seasonal influenza (CDC – Influenza (Flu) | Weekly Report: Influenza Summary Update 20, 2004-2005 Season, n.d.). H1N1 strains also exist within pigs (swine influenza) and birds (avian influenza), and sometimes they can jump between animals and humans, causing pandemics. What is unique about influenza is its ability to mutate rapidly, and this is why the flu shot is given every year. When the virus mutates, the proteins on its surface change and the immunity the body used to have no longer works since the immune system used to use those proteins to recognize the virus (Miksanek, 2007). While the mortality of influenza is generally low (less than 2%), the ability of it to spread far and wide can lead to massive death, as was the case during the Spanish Flu, as 0.6% of the US population died (which is equivalent to about 2 million people today).
How did we Fight It?
Like many diseases, quarantine was used to prevent the spread of influenza. Unfortunately, this was not that effective for preventing spread because the infectious stage of influenza begins before the individual develops symptoms, making it very hard to tell who needs to be quarantined until it is too late (Miksanek, 2007). In the case of influenza quarantines, it is mostly done as a way to reassure the public that some action is being taken. Face masks are another measure famously used during influenza outbreaks. In San Fransisco during the Spanish flu, people were regularly jailed for not wearing face masks (Miksanek, 2007).
Vaccines
As mentioned before, the rapid ability of influenza viruses to mutate gives them a huge advantage over vaccines. The immune system defends against flu viruses by remembering what the proteins on the virus surface look like, but when the virus mutates, it changes these proteins so the body can no longer recognize it as a pathogen to eliminate it. This is why the flu vaccine is given every year. Just because you might have been vaccinated last year does not mean you are immune next year, and it is recommended you get your flu vaccine every year for this reason.
But how do they make a new vaccine every year? Well, they do so by looking at what flu strains are infecting people in the other hemisphere. The flu usually hits us mostly in the fall season, and since fall is different for people below the equator, we can ‘look into the future’ by seeing what strains are active during their fall. Then, scientists can prepare the proper vaccine and circulate it across the country. Pretty neat.
There are many benefits to getting the flu vaccine, and a huge one is decreasing spread of flu among the population. While you might not die if you catch the flu, you will feel yucky. But by getting vaccinated, you will also protect our most vulnerable people in society, like the elderly and very young or those who cannot get vaccinated due to compromised immune systems. So, get vaccinated and save lives!
References
CDC – Influenza (Flu) | Weekly Report: Influenza Summary Update 20, 2004-2005 Season. (n.d.). Retrieved August 27, 2023, from https://www.cdc.gov/flu/weekly/weeklyarchives2005-2006/05-06summary.htm
Miksanek, T. (2007). Twelve Diseases That Changed Our World. JAMA: The Journal of the American Medical Association, 298(24), 2914–2920.