Whooping cough (pertussis) booster vaccine
(Date of issue: October 2016. Version: 2)
This factsheet has been written for members of the public by the UK Teratology Information Service (UKTIS). UKTIS is a not-for-profit organisation funded by Public Health England on behalf of UK Health Departments. UKTIS has been providing scientific information to health care providers since 1983 on the effects that medicines, recreational drugs and chemicals may have on the developing baby during pregnancy.
What is it?
The whooping cough (pertussis) booster vaccine contains an inactivated form of the whooping cough bug. When injected, this does not cause illness but stimulates the body to develop immunity that protects against whooping cough infection. The whooping cough booster vaccine recommended for pregnant women in the UK is Boostrix IPV®. This vaccine also protects against three other serious illnesses (tetanus, diphtheria and polio).
Why is it advised that I receive the whooping cough booster vaccination during pregnancy?
It is currently recommended that all pregnant women in the UK are vaccinated with Boostrix IPV® between 16 and 32 weeks of pregnancy to help protect their baby from catching whooping cough after birth. Women can still be vaccinated after 32 weeks of pregnancy, but vaccination at this stage of pregnancy may not offer as much protection to the baby.
Levels of the whooping cough bug have been higher than usual in the UK over the past few years. Whooping cough infection in babies under 3 months old can be very serious and may even cause death. Vaccinating a newborn baby against whooping cough is not thought to protect the baby as his/her immune system will not yet be ready to respond to the vaccine.
However, when a pregnant woman receives the whooping cough booster her immune system produces antibodies (molecules that fight infections) that cross the placenta to the unborn baby. The antibodies from the mother remain in the baby for a few months after birth and help to protect the baby from whooping cough infection until his/her first whooping cough vaccination is given, usually at two months of age. Studies have shown that the UK whooping cough vaccination programme in pregnant women has been effective at reducing the risk of whooping cough in babies from birth to two months of age, and also reducing the risk of babies up to 2 months of age being admitted to hospital with whooping cough.
Do I still need the booster if I have had whooping cough or have been vaccinated before?
It is not known for how long a person who has had either a whooping cough vaccination or a whooping cough infection remains resistant to whooping cough. It is therefore recommended that every pregnant woman receives Boostrix IPV®, even if they have been vaccinated during a recent previous pregnancy or if they have had whooping cough in the past.
Can I still be vaccinated with Boostrix IPV® if I have recently had a tetanus booster?
The tetanus booster vaccine used for adults in the UK (Revaxis®) does not protect against pertussis. Women who have recently had a tetanus booster can still receive Boostrix IPV® after week 16 of pregnancy, although there should be an interval of at least 4 weeks between the two vaccinations.
Can the whooping cough booster vaccine cause miscarriage?
Prior to 2016, UK guidelines suggested that pregnant women were vaccinated against pertussis from 28 weeks of pregnancy which is beyond the risk period for miscarriage. Because of this, miscarriage rates have been studied in very few pregnant women receiving pertussis vaccine. However, studies that include small numbers of women who were vaccinated against pertussis in early pregnancy have not suggested that their risk of miscarriage was increased.
From 2016, pertussis vaccination is recommended after week 16 of pregnancy to maximise the protection provided to the baby. In practice, most women will be offered vaccination at or after their 20 week scan. At this stage of pregnancy, the risk of miscarriage is generally considered to be very low.
Can the whooping cough booster vaccine cause birth defects in my baby?
A baby’s body and most internal organs are formed during the first 12 weeks of pregnancy. It is mainly during this time that some medicines are known to cause birth defects. Vaccination against whooping cough from 16 weeks of pregnancy onwards will therefore not cause physical birth defects in the baby.
Can the whooping cough vaccine cause stillbirth?
No increased risk of stillbirth was seen in one study of over 17,000 pregnant women in the UK who received a pertussis, tetanus, diphtheria and polio vaccine during the third trimester.
There is also information from the US about a vaccine called Tdap that protects against whooping cough, tetanus and diphtheria. Approximately 8,500 pregnant women who received Tdap during later pregnancy were studied. There is also no evidence that vaccination with Tdap during pregnancy increases the risk of stillbirth. However, the Tdap vaccine is not exactly the same as the pertussis, tetanus, diphtheria and polio vaccine, so we cannot be sure that this information relates to women receiving Boostrix IPV® during pregnancy.
Can the whooping cough vaccine cause preterm birth, or my baby to be small at birth (low birth weight)?
No increased risk of the baby being born earlier than expected, or of having a baby with a low birth weight (<2,500g) was seen in one study of over 6,000 pregnant women in the UK who received a pertussis, tetanus, diphtheria and polio vaccine during the third trimester.
Rates of preterm birth and low birth weight were studied in over 33,000 babies in the US born to women vaccinated with Tdap (that protects against whooping cough, tetanus and diphtheria) in pregnancy. There was no evidence of increased risk of either of these outcomes. However, the Tdap vaccine is not exactly the same as pertussis, tetanus, diphtheria and polio vaccines, so we cannot be sure that this information relates to women receiving Boostrix IPV® during pregnancy.
Can the whooping cough vaccine cause learning or behavioural problems in the child?
A baby’s brain continues to develop right up until the end of pregnancy. It is therefore possible that taking certain medicines at any stage of pregnancy could have a lasting effect on a child’s learning or behaviour.
There is no known link between being vaccinated with Boostrix IPV® in pregnancy and learning or behavioural problems in the child later on in life. There are, however, no scientific studies that have specifically investigated a link with these problems.
One small study from the US compared learning and behaviour in 33 one year old children who had been exposed in the womb to Tdap vaccine that protects against whooping cough, tetanus and diphtheria, and children who were exposed to the Tdap vaccine after birth. There were no differences in development between the two groups of children.
Will my baby need extra monitoring during pregnancy?
Being vaccinated with Boostrix IPV® during pregnancy is not expected to cause any problems that would require extra monitoring of your baby.
Who can I talk to if I have questions?
If you have any questions regarding the information in this leaflet please discuss them with your health care provider. They can access more detailed medical and scientific information from www.uktis.org.
Up to 1 out of every 5 pregnancies ends in a miscarriage, and 1 in 40 babies are born with a birth defect. These are referred to as the background population risks. They describe the chance of these events happening for any pregnancy before taking factors such as the mother’s health during pregnancy, her lifestyle, medicines she takes and the genetic make up of her and the baby’s father into account.
Medicines use in pregnancy
Most medicines used by the mother will cross the placenta and reach the baby. Sometimes this may have beneficial effects for the baby. There are, however, some medicines that can harm a baby’s normal development. How a medicine affects a baby may depend on the stage of pregnancy when the medicine is taken. If you are on regular medication you should discuss these effects with your doctor/health care team before becoming pregnant.
If a new medicine is suggested for you during pregnancy, please ensure the doctor or health care professional treating you is aware of your pregnancy.
When deciding whether or not to use a medicine in pregnancy you need to weigh up how the medicine might improve your and/or your unborn baby’s health against any possible problems that the drug may cause. Our bumps leaflets are written to provide you with a summary of what is known about use of a specific medicine in pregnancy so that you can decide together with your health care provider what is best for you and your baby.
Every pregnancy is unique. The decision to start, stop, continue or change a prescribed medicine before or during pregnancy should be made in consultation with your health care provider. It is very helpful if you can record all your medication taken in pregnancy in your hand held maternity records.