Influenza, a potentially deadly disease, is estimated to result in between 1,500 and 3,500 deaths and more than 18,000 hospitalisations annually in Australia (1). When it comes to pregnant women, the risk of hospitalisation with H1N1 influenza compared with non-pregnant women increases five times (2).
During pregnancy, the immune system is gravely repressed, increasing the chances of getting the flu. Therefore, pregnant women are at greater risk of having austere complications from the virus as influenza infection increases the risk of premature birth, suboptimal foetal growth and stillbirth. Fortunately, maternal flu vaccination offers protection against these complications (3,4,5), and pregnant women are eligible for free vaccination under the National Immunisation Program. Pregnant women are advised to have the flu shot, especially if they fall under more than one at-risk group category.
There is no doubt regarding the safety of the flu jab for pregnant women, including in the first trimester.
A recent study (4) showed that the influenza vaccine is not associated with an increased risk of foetal death; instead, it protects against this. A pregnant woman vaccinated has a 70% reduced risk of getting influenza. The risk of foetal death is nearly doubled for women with confirmed influenza. It was found that there were 16 foetal deaths among the 2,278 pregnant women who were diagnosed with influenza. Vaccination against flu in pregnant women also protects the baby during the first vulnerable months of life.
Flu vaccination during pregnancy: Pregnant Women are the most vulnerable risk group
The World Health Organization (WHO) Strategic Advisory Group has identified pregnant women as the most important risk group for seasonal vaccination against influenza as antibodies in pregnant women are actively transported to the foetus, more so during late pregnancy (2).
The influenza vaccine can be given at any time during pregnancy. However, protecting women during their second and third trimesters is a priority because this is the time when serious complications from influenza are more likely to occur. Getting the flu shot when pregnant is the surest way to protect young babies aged 6 months or younger. This age is when they are most susceptible to the disease but least responsive to vaccines.
During pregnancy, inactivated influenza vaccination has proven safe for the unborn child.
1. Newall AT, Wood JG, MacIntyre cR. Influenza-related hospitalisation and death in Australians aged 50 years and older. Vaccine 2008; 051: 3
2. NHMRC 2008. Australian Immunisation Handbook. 9th Edition.
3. Englund J et al. Maternal immunisation against viral disease. Vaccine 1998;16: 1456–63.
4. Jit et al. The cost-effectiveness of vaccinating pregnant women against seasonal influenza in England and Wales. Vaccine 2010; 29: 115–122.
5. Källén B, Olausson PO. Vaccination against H1N1 influenza with Pandemrix(®) during pregnancy and delivery outcome: a Swedish register study BJOG 2012; 119: 1583–90.
6. World Health Organisation. SAGE Meetings. 2012
