In a nutshell
It’s safe to get the flu jab at any stage of your pregnancy – both for you and for your unborn baby.
The expert view
“The flu jab is not only safe in pregnancy but is actively recommended,” say our expert GP Dr Philippa Kaye. “It is safe for your baby and may also pass some protection onto your baby in their first few weeks of life.”
There are several studies, showing the flu jab to be safe at all stages of pregnancy, including the 1st 3 months.
The most often quoted research includes a 2009 study into flu-vaccine safety in pregnancy by researchers at John Hopkins School of Medicine in Baltimore, US, and a 2012 study into flu-vaccine safety in the 1st trimester of pregnancy by researchers at the University of Texas Southwestern Medical Centre in the US.
Another US study, undertaken in 2017, finds no increased risk of birth defects in babies born to mothers who were given the flu vaccine.
What do I need the flu jab in pregnancy?
In 2012, experts from the World Health Organisation recommended that pregnant women should be made the top priority in every country’s flu immunisation programme.
This is because, according to Oxford University’s independently run Vaccine Knowledge Project, there’s strong evidence that pregnant women have a greater risk than the rest of the population of developing serious complications if they get flu, particularly in the last 3 months of pregnancy.
There is also strong evidence that catching flu in pregnancy can have an effect on your unborn baby. According to the Vaccine Knowledge Project, babies born to women who have had flu are up to 4 times more likely to be born prematurely and to have a low birthweight.
If you catch flu, complications can include:
- Bronchitis, a chest infection that can become serious and develop into pneumonia
- Otitis media (middle ear infection)
- Septic shock (blood infection that causes a severe drop in blood pressure)
- Meningitis (infection of the brain and spinal cord)
- Encephalitis (inflammation of the brain)
- Your baby could be born prematurely and/or have a low birthweight
When you have the flu vaccine in pregnancy, you also pass some protection on to you baby, which will last for the first few months of their life.
Can the flu jab give you the flu?
No. The flu jab doesn’t contain any live viruses, so the vaccine itself can’t cause flu.
What it does instead is stimulate your immune system to develop antibodies to fight the strains of flu you’ve been immunised against.
But it is possible (but not common) to get flu after having had the flu jab, though – and that would be for 1 of 2 main reasons:
- You’ve been exposed to a flu virus in the 10 to 14 days after the jab when your body hasn’t yet built up full immunity
- You’ve been exposed to a strain of flu virus you’ve not been vaccinated against (there are many different strains flu viruses and each year the flu jab changes slightly to try to protect you against the strains that are thought to be most prevalent).
What are the side effects of the flu vaccine?
“The most common side effect is a sore arm, with some redness around the injection site,” says Dr Philippa.
Other side effects can include:
- swelling, bruising, hardness at the injection site
- slightly raised temperature (fever)
- aching joints or muscles
- feeling generally unwell
These side effects, if you experience them, usually last 1 to 2 days.
“It doesn’t hurt but I did have a dead arm for a couple of days,” says Littlemissimpatient in a post on our MadeForMums Chat Forum.
“I had my jab at 10 weeks after lots of ummin and aching. I was told any risks associated with having the vaccine are non-existent compared to the risks of catching the flu when pregnant.”
When should I have the flu jab?
The flu vaccine is normally available from September until around January or February each year and is free for pregnant women.
If I had the vaccine last year, do I need to have it again?
Yes, because the strains of the virus that cause flu change every year.
This means that the flu (and the vaccine) this year may be different from last year.