It may be too late to dress up like Barbie or Ken for Halloween now that it’s early December already. It may be too late to dress up like Barbie or Ken for Thanksgiving Dinner too. But as long as it’s still either the Fall or Winter season, it is definitely not too late to get the flu shot. As long as you are somewhere in the October through March time frame, you probably want to get vaccinated against influenza as soon as you can.
That’s because the influenza season in the Northern Hemisphere can extend all the way from as early as October to as late as May the following calendar year. In fact, until you’ve gotten well into the New Year, chances are you and everyone around you haven’t even seen the worst of the flu season yet. Flu activity is typically highest from December through February with the peak amount of influenza virus activity most commonly occurring in February. That’s why it’s good idea to always secure your protection well in advance of Valentine’s Day. And in this case, protection means getting vaccinated against the flu.
Now, flu activity can follow very different patterns each season. In the four decades from the 1982-1983 flu season through the 2021-2022 flu season, the peak of the flu season has been in February a total of 17 times. December has been the next most common peak month at seven times. January and March tied for third place at six times apiece. And October, November, and April have been the peak months only once each, according to data from the Centers for Disease Control and Prevention.
There’s a saying amongst epidemiologists that if you’ve seen one flu season, you’ve seen just one flu season. Every year can be different from previous years. Unless you have a DeLorean that serves as a time machine or some other way of traveling to and from the future, it’s impossible to predict exactly what this current flu season will look like. You cannot be sure about when peak flu activity will occur, how bad things will be, or whether this will be the season when there is a surge in cases in the later Spring.
If you haven’t yet been vaccinated, it’s a good idea to get the flu vaccine as soon as possible. Keep in the mind that the flu vaccine isn’t like a trench coat and doesn’t start protecting you the moment that you get it. Your immune system has to first see the weakened or inactivated flu particles from the vaccine, essentially say, “WTF is this, this doesn’t belong in my body,” and then mount an immune response against them, which can take up to two weeks.
This two-week lag time to protection is a big reason why it’s important to get the flu vaccine now without further delay. This will help protect you in time for the last two weeks of December, which may be filled with interactions with other people, objects, and surfaces, especially if you celebrate Christmas, Kwanzaa, New Year’s Eve, New Year’s Day, and the annual unofficial Holiday of going to stores to return all the presents that you didn’t want but somehow received.
Late September to mid-October is typically the best time to get vaccinated against the flu to make sure you are protected before flu activity really starts to increase, as demonstrated by computer modeling studies published by our PHICOR Team in the scientific journals Vaccine, the American Journal of Managed Care, and Medical Care. It is is possible to get vaccinated a bit too early, such as in August, since the protection offered by the flu vaccine may start waning after six months, leaving you less protected the following May when the flu may still be around.
Keep in mind that while the flu vaccine can offer good protection against the flu, it doesn’t function like a gigantic full-body concrete condom. It won’t offer you 100% protection. Instead, it’s protection can vary from 30% to 60% depending on well the flu virus strains put in the vaccines in the lead up to the flu season end up matching the strains that actually circulate that season. So just because you got the flu shot already doesn’t mean that you should stop washing your hands frequently and thoroughly, begin hugging and kissing people who may be coughing, sneezing, feeling run down or hot (hot temperature-wise, that is), and abandon all other infection prevention measures. Otherwise, your New Year’s Eve may turn out to be a Flu Year’s Eve.
Of course, reducing your chances of getting infected is not the only benefit of the flu shot. Even if you do end up getting infected, being vaccinated can significantly reduce the severity of your symptoms and your chances of getting hospitalized and dying. Most commonly the flu will result in four to seven days of fevers, chills, coughing, a sore throat, a runny or stuffy nose, muscle or body aches. headaches. fatigue, vomiting, diarrhea, or other not very pleasant symptoms. The can be so unpleasant that you end up missing school and work throughout this time period.
Things can get even worse, though, especially if you have a weaker immune system. Each year from 2010 through 2022, somewhere between 9.4 million and 41 million people have gotten sick from the flu, between 100,000 and 710,000 people have been hospitalized and between 4,900 and 52,000 people have died. Catching the flu is not the same as catching the common cold. The flu could leave you a lot more sick with some potentially terrible consequences.
Finally, even if you think you’ve had the flu already this year, it is still a good idea to get the flu shot. Many different microbes can cause flu-like illnesses such as respiratory syncytial viruses (RSV) and adenoviruses. So, unless you actually got tested for the flu, you cannot be sure if you’ve actually had the flu, meaning that its’ probably still worth a shot.