What is the flu?
Influenza (the flu) is a respiratory virus that targets the throat, nose, and occasionally lungs. Unlike a cold, it comes on suddenly, causing symptoms such as fever, body aches, sore throat, fatigue, and coughing. Similar to many respiratory illnesses, it is transmitted through droplets that can be spread when an infected person coughs, sneezes, or talks and can also be contracted via surfaces. It is highly contagious; transmission of the virus is possible one day before the onset of symptoms and can last for up to seven days following symptom onset. The CDC estimates (based on a 2018 study) that around 8% of people in the US are infected with the flu and develop symptoms each season (although this varies depending on the year). Both older people (aged 65 and up) and younger children (aged 5 and younger) are at a higher risk of developing complications from the flu. Those at risk also include people with long-term medical conditions, those who are immunocompromised, and people who are pregnant.
When is the flu most prevalent?
In the US, the flu season occurs during the winter, starting as early as October, peaking between December and February, and ending in May. This is different from the flu season in the southern hemisphere, which occurs between April and September. It is theorized that the flu’s seasonal pattern can be attributed to a population’s lifestyle in the winter months. Generally, as the weather gets colder, people tend to spend more time indoors which makes it easier for the flu to spread. Additionally, with it being colder and dryer, it may be easier for the virus to live longer.
What is the flu vaccine and why is it important?
The flu vaccine either comes as a nasal spray or a shot. In the US, it protects against four strains of flu viruses. After receiving the vaccine, it takes about two weeks for antibodies to develop. Because of the flu virus’ ability to mutate quickly, the flu shot should be given yearly. Each annual vaccine is formulated to best protect against the dominant strains of that year. This also means that the flu shot’s effectiveness can vary depending on the season. Previous studies have estimated that the flu shot can be between 50% and 60% effective for healthy people ages 18 to 64. For some years, this effectiveness can be lower. While the lower effectiveness may dissuade people from getting the vaccine, it doesn’t mean that the shot is less important. On average, 200,000 Americans are hospitalized from the flu annually and 8,200 to 20,000 die. Neither of those are insignificant statistics. Both the CDC and Mayo Clinic have stated that the flu shot is the best way of preventing infection from the flu. Similar to the COVID-19 vaccines, getting the flu vaccine could lessen the severity of an infected person's symptoms, reducing the likelihood of hospitalization and death.
Who should get the flu shot?
Anyone aged 6 months and up can receive the flu shot. It is recommended that you get your shot in September or October (ideally by the end of October). However, even if you get your flu vaccine by February, you can still reduce your risk of contracting or being hospitalized with the flu.
Given the strain on hospitals from COVID-19, it is especially important to take measures like getting vaccinated to reduce your risk of severe infection and hospitalization. Those who are younger children, older adults, immunocompromised, or pregnant are more at risk for developing severe illness from the flu, so vaccination is incredibly beneficial in protecting these populations. However, this doesn’t mean that only these groups should get their flu shots. Population immunity (when a large part of a community is immune to a virus/disease) is increased when more people get vaccinated. Like many other vaccines, getting the shot not only protects you from illness; it makes it less likely that you will contract and spread the flu to your community. Additionally, in the times of COVID-19, having any sort of coronavirus-like symptoms can cause a major disruption to your life. Reducing your chances of getting the flu will also make it less likely that you get sick and need to isolate. Given that we are currently in flu season, it is important to continue to protect ourselves from the virus. The flu vaccine is the best measure to take in this effort.