Perhaps you procrastinated – that Halloween costume wouldn’t make itself and neither would the Thanksgiving turkey – and now you’ve realized, just as you’re about to gather with your friends and family again, that you’ve neglected your seasonal vaccines.
Public health authorities recommend people get annual vaccines for influenza and Covid-19 in the early fall – around September and October. But infectious disease experts say even if you didn’t get shots then, it can make a difference today.
“It’s not too late,” said Dr Sean T Liu, an infectious disease expert at Mount Sinai hospital in New York City. “The recommendation is still to get one if you haven’t gotten one.”
Vaccines for influenza and Covid-19 are distinct but related. Public health authorities recommend that most people six months and older get them in the early fall. They are safe to receive at the same time, and especially important for the elderly or people who have never been vaccinated, the immunocompromised, and people living with chronic conditions, such as obesity and diabetes.
With only about 20% of the adult population under 65 years old vaccinated against Covid-19 and about 38% vaccinated against flu, according to government authorities, Liu said it is even more important for people to go get vaccinated.
“Vaccines are kind of like your community work in a sense – it’s to help the community and protect those people that may be not as healthy or get really harmed from illness,” said Liu. “Your job is to not be one of those carriers.”
Each year, experts recommend people get shots in the early fall to have good protection during the flu season peak – generally around December. However, there’s variability in the exact peak each year, which is part of the reason a flu shot can still be a good idea.
In 2023, the flu season peaked in late December with cases elevated until May. By comparison, in 2018 the flu season did not peak until about mid-February, but was in steep decline by April. That timing explains why the shots can still protect you from the worst of the season, generally in January and February, even if you get them later in the year.
In the 2023-24 season, an estimated 40 million people got sick with the flu, sending 18 million to the doctor and another 470,000 to the hospital. An estimated 28,000 died. In the same season, more than 916,300 people were hospitalized because of Covid-19 and 75,500 died.
“Our top recommendation for protecting yourself and your loved ones from respiratory illness is to get vaccinated,” said Dr Mandy Cohen, director of the Centers for Disease Control and Prevention (CDC).
This year the flu vaccine is trivalent – or will protect you against three strains of flu. The current Covid-19 vaccine is expected to protect people against a few variants now circulating.
You won’t get maximum protection against influenza and Covid-19 immediately – it takes about two weeks for the immune system to respond to each vaccine. It is safe to get the shot together, according to the CDC. In fact, drug companies are now studying whether the shots can be combined.
There are side effects, which are usually mild but unpleasant. For the flu shot, common effects include soreness around the injection site, headache, fever, muscle aches, nausea and fatigue.
There is also the potential for rare but serious side effects, including Guillain-Barré syndrome, which includes tingling, numbness and paralysis. The chances of suffering from Guillain-Barré are “remote,” according to the CDC, and which studies have placed at a rate of about 1-2 cases per million.
The Covid-19 vaccine has similar common, mild and unpleasant side effects, including muscle soreness, headache and chills. Although rare, there is also the possibility of severe allergic reaction and heart inflammation called myocarditis. Heart complications are more likely after a Covid infection than from the vaccine, CDC studies have found.
People who have been recently infected with Covid may choose to delay the vaccine for three months after the onset of symptoms of a positive test with no symptoms, the CDC said.
“Even if you are not at high risk” for severe disease, “you really want to protect the people who might be high risk for that,” said Liu. “The point about vaccines – the purpose of a vaccine – is to protect a population of people.”
