Guidance

Pertussis (whooping cough) vaccination programme for pregnant women: information for healthcare practitioners

Updated 28 June 2024

Applies to England

Background

In 2012, the UK reported the largest increase in pertussis activity in over 2 decades. At that time, the greatest numbers of cases were in adolescents and young adults, but the highest rates of disease, morbidity and mortality occurred in infants less than 3 months old. Infants in this age group are most at risk of serious disease and are too young to be fully protected through routine vaccination. In 2012, a total of 14 infant deaths were reported in England and Wales.

In response to the national outbreak, the Department of Health and Social Care issued a letter from the Chief Medical Officer (CMO) which announced the introduction of a temporary immunisation programme for pregnant women.

The aim of the programme was to boost pertussis antibodies in the vaccinated woman in pregnancy, so that pertussis specific antibodies would be passed from the mother to her baby. This was to provide the infant with protection from birth until they attended for their own routine vaccines at 8 weeks of age. The programme commenced on 1 October 2012.

In June 2014, the Joint Committee on Vaccination and Immunisation (JCVI) reviewed the maternal pertussis vaccination programme and agreed that “acceptance of the programme amongst pregnant women was good and that relatively high coverage, coupled with high effectiveness of the vaccine had resulted in a reduction in disease and mortality in young infants”.

Two different studies led by Public Health England (now UK Health Security Agency) (an observational study on the effectiveness of maternal pertussis vaccination in England and a case-control study to estimate the effectiveness of maternal pertussis vaccination in protecting newborn infants in England and Wales, 2012 to 2013), demonstrated:

• high vaccine effectiveness of around 90% against confirmed pertussis in infants aged less than 3 months
• that the greatest proportionate fall in confirmed cases and hospital admissions was observed in those under 3 months of age in the years after maternal vaccine was introduced

In light of the success of the vaccination programme in saving infant lives and against the continued high levels of pertussis activity in age groups older than one year, in June 2019 the JCVI advised that it should continue as a routine programme.

When pregnant women should be vaccinated

Since 1 April 2016, vaccination has been recommended from as early as week 16 of pregnancy, although the optimal window is between weeks 20 and 32. This gives pregnant women greater opportunity to take up the offer of vaccination, has been shown to offer greater protection against hospitalisation with pertussis in infants born prematurely who may be particularly vulnerable to complications and potentially improves neonatal antibody levels.

Although it was initially thought that vaccination later in pregnancy would lead to higher levels of maternal antibodies during the period of optimal transplacental transfer, that is around or after 34 weeks of gestation, a study by Eberhardt and others (2016) showed that vaccination before 28 weeks actually provides significantly higher levels of antibodies in cord blood. They suggest that although the rate of transfer is higher later in pregnancy, there is more time for antibodies to be transferred for those vaccinated earlier in pregnancy, and therefore the cumulative amount overall is higher in these women and their babies. A study by Amirthalingam and colleagues in 2022 looked at vaccine effectiveness by timing of administration in pregnancy and confirmed that vaccination in the second trimester potentially increased overall maternal vaccine uptake with sustained high vaccine effectiveness and impact against early infant disease.

For operational reasons, vaccination should ideally be offered at the fetal anomaly scan appointment at around 20 weeks of pregnancy. Offering vaccination at this time will avoid any associations with any unrelated adverse events that may be detected at the time of the routine anomaly antenatal scan being made.

Evaluation of the programme

Disease incidence

Following the introduction of the maternal vaccination programme, there was a decline in pertussis incidence in infants under 3 months of age from 234 per 100,000 in 2012, to 52 per 100,000 in 2019 and 0.7 per 100,000 in 2021, after public health measures to help control the COVID-19 pandemic were introduced. Pertussis is a cyclical disease, with increases occurring every 3 to 5 years, and pertussis activity usually peaking each year in quarter 3. This natural cycle was affected by COVID-19 interventions, but cases have been increasing since summer 2023 and have continued to increase in 2024. In 2023, incidence was highest in infants under 3 months, and between January and April 2024 there were 181 confirmed pertussis cases in infants aged under 3 months (101 cases in the same period in 2012). Further information about the current epidemiology of pertussis is available at Confirmed cases of pertussis in England by month.

Maternal vaccine coverage

Although for the first few years of the programme, vaccine coverage was around 70%, uptake has fallen below this level year on year since 2020. In 2019 to 2020 it was 70.5%, in 2020 to 2021 it was 67.8% and in 2021 to 2022, it was 64.7%. For the 2022 to 2023 financial year, vaccine coverage was 60.7%. In December 2023, pertussis vaccine coverage in pregnant women in England was 59.5%, with lower uptake (down to below 40%) in some parts of the country. Vaccine coverage data are available at Pertussis immunisation in pregnancy: vaccine coverage (England).

Effectiveness of maternal immunisation at preventing pertussis in young infants

In England, vaccine effectiveness (VE) was shown to be 91% in the reduction of laboratory-confirmed cases in infants aged less than 3 months ^{[footnote 1]} and 93% in preventing laboratory-confirmed cases in infants aged less than 8 weeks ^{[footnote 2]}. In the US, studies of effectiveness among infants aged less than 8 weeks showed a range of effectiveness between 85 and 91%. They also showed that disease was significantly less severe among infants born to vaccinated mothers ^{[footnote 3]}.

In the 12 years prior to the introduction of maternal pertussis vaccination in October 2012, 63 deaths occurred in infants with confirmed pertussis. Since the introduction of pertussis vaccination in pregnancy, from 2013 to the end of April 2024, there have been 29 deaths in babies with confirmed pertussis who were all too young to be fully protected by infant vaccination. Sadly, this includes 8 deaths in infants who had contracted pertussis between January and April 2024. Of the 29 infants that died, 23 had mothers who were not vaccinated in pregnancy. Maternal vaccination is very effective against pertussis disease and hospitalisation (‘Optimization of Timing of Maternal Pertussis Immunization’ Clinical Infectious Diseases 2023). Calculated maternal vaccine effectiveness against infant death was updated to include recent deaths to the end of March 2024 and remains very high at around 92% (UKHSA, 2024). Vaccinating in pregnancy offers the best protection against severe pertussis disease in young babies.

Pertussis (whooping cough)

Pertussis, also known as whooping cough, is a respiratory infection caused by Bordetella pertussis bacteria. Pertussis usually begins with mild, cold-like symptoms that develop over one to 2 weeks into coughing fits which can be severe. The cough often can last for 2 to 3 months and because of this, in some countries, pertussis is known as the ‘100-day cough’.

Pertussis most commonly affects infants, and very young infants are at highest risk of serious complications, of needing admission to hospital or of dying. However, pertussis does occur in older children, adolescents and adults. Prior to the COVID-19 pandemic, the number of cases of pertussis in the UK was high in all age groups, apart from in children who had recently been vaccinated (those aged from 4 months to around 9 years). Although cases of pertussis were low during the pandemic due to measures such as social distancing, the number of pertussis cases started to rise again from summer 2023.

The Green Book pertussis chapter 24

The Green Book pertussis chapter 24 includes detailed information about pertussis and the pertussis vaccines. Healthcare practitioners offering the pertussis vaccination programme to pregnant women should familiarise themselves with the information in this Green Book chapter.  

Pertussis vaccination programme for pregnant women

Aim of the programme

The programme protects infants by boosting pertussis immunity in pregnant women, which enables the mother to transfer a high level of pertussis antibodies across the placenta to her unborn child. This has been shown to passively protect infants against pertussis from birth until they are due their first dose of primary immunisations at 8 weeks of age. The maternal antibodies will be naturally broken down by the infant in their first months of life.

Although most women will have been vaccinated or exposed to natural whooping cough in childhood, receiving a pertussis-containing vaccine from week 16 of their pregnancy will temporarily boost their antibody levels.

Whilst it is recommended that women are offered the vaccine between weeks 16 to 32 of pregnancy, usually around the time of the fetal anomaly scan (20 weeks), women may still be immunised after week 32 of pregnancy until delivery. However, this may not offer as high a level of passive protection to the baby, particularly if they are born pre-term.

Safety of vaccine administration during pregnancy

There are no concerns about the safety of the inactivated pertussis-containing vaccine at any stage in pregnancy.

Inactivated vaccines contain no live organisms, cannot replicate and therefore cannot cause infection in either the mother or the fetus.

Since the introduction of the pertussis vaccine in pregnancy programme in October 2012, the Medicines and Healthcare products Regulatory Agency (MHRA) has continually monitored the frequency and type of adverse events using the Yellow Card Scheme and additionally used the Clinical Practice Research Datalink to study pregnancy outcomes following vaccination.

The MHRA found no safety concerns relating to pertussis vaccination in pregnancy based on a large observational cohort study of 18,000 vaccinated women with similar rates of normal, healthy births in vaccinated and in unvaccinated women. The study found no evidence of an increased risk of stillbirth in the 14 days immediately after vaccination or later in pregnancy and found no evidence of an increased risk of any of an extensive predefined list of adverse events related to pregnancy. Other studies have similarly not identified safety concerns ^{[footnote 4]}.

Pertussis-containing vaccines are routinely given during pregnancy in vaccination programmes in many other countries, including the US, New Zealand and Australia, so there is an increasing body of evidence to support the safety of pertussis immunisation during pregnancy. No increased risk for the development of severe maternal adverse events (for example, postpartum endometritis, preterm delivery, and preterm premature rupture of membranes) or fetal and neonatal outcomes (for example, low birth weight, very low birth weight, small for gestational age, birth defects, and need for neonatal intensive care unit admission) has been identified ^{[footnote 5]}.

A Canadian study ^{[footnote 6]} followed children up to their sixth birthday and found no significant increased risk in adverse childhood outcomes and pre-natal pertussis vaccination.

Protecting each pregnancy

Studies have shown a significant decline in antibodies within the first year after maternal vaccination. As the persistence of antibodies after a single dose of pertussis-containing vaccine in pregnancy is short and therefore unlikely to ensure infant protection during consecutive pregnancies, vaccination, ideally between weeks 20 and 32, is currently recommended in every pregnancy, regardless of the interval between subsequent pregnancies.  Repeated pertussis-containing vaccinations in consecutive pregnancies are well tolerated.

One dose of pertussis-containing vaccine per pregnancy is recommended for women carrying twins or multiple babies.

Women beyond 32 weeks of pregnancy

Administering the vaccine between weeks 16 and 32 of pregnancy is most likely to ensure sufficient levels of pertussis antibodies are transferred across the placenta, providing passive immunity to the unborn child. However, if a woman reaches 32 weeks of pregnancy and has not received a pertussis-containing vaccine, it should still be offered.

If the dose of vaccine is received within 2 weeks of the baby’s birth it may not provide passive protection to the infant; this is because antibody levels in adults peak around 2 weeks after a dose of pertussis vaccine has been given and there would be insufficient time for the mother to make a good response and have antibodies to pass across the placenta.

Vaccination late in pregnancy may, however, directly protect the mother against disease and thereby reduce the risk of exposure to her infant.

Post-natal vaccination

Women who have not received a pertussis-containing vaccine during pregnancy can be offered it in the 8 weeks following birth (up until their child receives their first dose of pertussis-containing vaccine). This will protect the woman and may prevent her from becoming a source of infection for the infant but it will not provide direct protection for the infant.

Primary vaccination of infants whose mother did not receive pertussis vaccine during pregnancy

The best way to protect newborn babies from pertussis is to make sure that they have benefited from the transfer of maternal antibodies before being born.

When a pregnant woman receives a pertussis-containing vaccine at the recommended time during her pregnancy, the unborn baby will receive some of the antibodies that are produced and will be protected during their first few weeks of life, until they are old enough to make a good response to their own vaccines.

The Green Book (chapter 11) advises that immunisations should not be given before the scheduled age unless there is a clear clinical indication for this. The first set of primary immunisations should be given from 8 weeks of age but can be given from 6 weeks of age, if required, in certain circumstances such as travel to an endemic country.

Administering the first set of primary immunisations before 6 weeks of age is not recommended as it may result in a sub-optimal response to the vaccine which could undermine good disease control. If an infant’s mother did not receive a pertussis containing vaccine in pregnancy, it is not recommended that the infant’s vaccination schedule is brought forward or started earlier than the recommended 8 weeks. However, as stated above, the infant’s mother can be offered pertussis-containing vaccine in the 8 weeks following birth if she did not receive it during pregnancy.

Pregnant women, and women presenting shortly after giving birth, with an incomplete or unknown vaccination history (primary vaccination against diphtheria, tetanus and polio)

Women who have not completed a primary course of 3 doses of tetanus, diphtheria and polio containing vaccines may be offered these whilst they are pregnant. The relevant chapters of the Green Book (Immunisation against infectious disease) advise that tetanus, diphtheria and polio containing vaccines “may be given to pregnant women when the need for protection is required without delay”.

There is no evidence of risk from vaccinating pregnant women or those who are breast-feeding with inactivated viral or bacterial vaccines or toxoids (Green Book chapter 6: contraindications and special considerations).

If a course of tetanus, diphtheria and polio containing vaccination is commenced before week 16 of pregnancy, a 4 week interval should be left between each dose.

Once the woman reaches 16 weeks of pregnancy or, around the time of her fetal anomaly scan, she should be offered a dose of a pertussis-containing vaccine. This should ideally be a diphtheria, tetanus and acellular pertussis/inactivated poliovirus (dTaP/IPV) vaccine to continue or complete the tetanus, diphtheria and polio vaccine course that has already been started. However, if she is being vaccinated by maternity services, it may be that only the Tdap vaccine will be available, and this should be given in order not to delay protection against pertussis which will benefit her baby. As this vaccine does not protect against polio, the woman will require an additional tetanus, diphtheria and polio (Td/IPV) vaccine at the end of her pregnancy. If she is being vaccinated in a primary care setting, the dTaP/IPV vaccine (usually used as a pre-school booster) should be offered as this will provide protection against pertussis and also count as one of her 3 primary doses of inactivated polio vaccine.

Women who have not completed their 3 dose primary course of Td/IPV containing vaccinations by the end of their pregnancy should be offered any outstanding doses post delivery.

If a woman has not received one or both of the booster vaccines offered following completion of the primary course, she should preferably be offered the dTaP/IPV vaccine but if only the Tdap vaccine is available (for example, in a maternity services setting), this should be given in order not to delay protection against pertussis which will benefit her baby and a polio containing vaccine (Td/IPV) should be given at the end of her pregnancy.

Most pregnant women will not be immunologically naïve to pertussis as they will have been primed during childhood through vaccination in infancy or through natural exposure during childhood. They will therefore not require additional doses of pertussis-containing vaccine unless they become pregnant again.

Any other outstanding vaccines should also be offered as appropriate. See the vaccination of individuals with uncertain or incomplete immunisation status algorithm. As measles, mumps, and rubella (MMR) is a live vaccine, and live vaccines are contraindicated during pregnancy, any woman who has not completed a 2-dose course of MMR prior to their pregnancy should receive it after their baby is born (which may be at the 6 to 8 week check if it has not been possible to offer it before this).

Breastfeeding mothers

Tdap or dTaP/IPV vaccine can be given to women who plan to breastfeed. There is evidence that pertussis antibodies in breast milk are increased after immunisation in pregnancy ^{[footnote 7]} and breastfeeding may therefore help reduce the likelihood of a baby becoming ill with pertussis. However, whilst there may be some pertussis antibodies transferred to the infant in the breast milk of vaccinated women, this will not be enough to replace the need for the infant to complete the recommended primary immunisation schedule on time.

Pregnant women diagnosed with confirmed or suspected pertussis in pregnancy

Although it might be expected that a woman diagnosed with whooping cough during pregnancy would transfer antibodies to her unborn baby, not all women make sufficiently high levels of antibodies following natural infection to ensure these can be passed across the placenta to the infant. As high levels of antibodies are made following vaccination, offering vaccine between 16 and 32 weeks of pregnancy should ensure that optimal antibody levels can be passed to the baby.

Recommended vaccine for the programme

From July 2024, the low dose tetanus, diphtheria and acellular pertussis (Tdap) vaccine (ADACEL) will be supplied for the maternal pertussis vaccination programme.

Any remaining stocks of the low dose dTaP/IPV vaccine (Boostrix-IPV) previously supplied for this programme should be used for the pre-school booster programme in primary care.

If this is the only vaccine available in maternity care settings, this vaccine can be offered until stocks of dTaP/IPV are exhausted and stocks of Tdap vaccine are received. Once Boostrix-IPV stocks are exhausted, only ADACEL should be offered.

Tdap and dTaP/IPV vaccines are prescription only medicines and immunisers should refer to the pertussis vaccination in pregnancy patient group direction (PGD) for full information on the supply and administration of these vaccines.

Change of vaccine in July 2024

In October 2022, the JCVI discussed the results from the ‘immunising mothers against pertussis’ (iMAP) studies ^{[footnote 8]},^{[footnote 9]} which looked at the antibody levels of infants of mothers who had received pertussis-containing vaccines (the dTaP/IPV vaccines Boostrix-IPV and REPEVAX) in pregnancy compared with an unvaccinated group. These infants were followed up until the age of 40 months when the preschool booster is scheduled and shortly after. Results showed a lower antibody response for the infants born to vaccinated mothers compared to unvaccinated mothers’ responses for polio types 1, 2 and 3 at 13 months, with the polio type 2 response being the most affected. The iMAP3 study polio type 2 results at preschool booster stage showed that pre and post booster antibody levels were lower in the children of vaccinated mothers compared to unvaccinated; however all were above the protective threshold. Although antibody responses were boosted after the pre-school booster, there was still a difference between those with vaccinated and unvaccinated mothers.

This finding – the blunting of the infant’s own antibody response – is consistent with the results of other international studies ^{[footnote 10]},^{[footnote 11]}, and the JCVI concluded that, to prevent this effect, a non-polio (IPV) containing pertussis vaccine should preferably be used in the maternal programme once it was possible to make this switch. A supply of the Tdap (ADACEL) vaccine has now been secured for the maternal vaccination programme from July 2024.

However, as the overall priority is to ensure that a maternal pertussis campaign remains in place as the programme continues to save lives, any remaining dTaP/IPV vaccine can continue to be used (in settings where it cannot otherwise be used for the pre-school booster) until stocks of this vaccine have been used up. It should also be offered if Tdap (ADACEL) is not available or is clinically contraindicated (for example because of severe allergy to latex).

Vaccine supply for this programme

ADACEL (Tdap) is the vaccine that will be supplied for the maternal pertussis vaccination programme from July 2024. ADACEL has been licensed for use in the UK since 2016 and is widely used. Millions of doses have been given in many other countries which have a maternal pertussis vaccination programme, including other European countries, USA and Australia. It contains low dose diphtheria, tetanus and pertussis antigens.

This vaccine can be ordered via ImmForm and is provided free of charge for this programme.

Although ADACEL® (non-IPV containing pertussis vaccine) is preferred for the maternal programme, if ADACEL is not available and to obtain it would result in a delay in vaccinating a pregnant woman, either Boostrix-IPV or REPEVAX vaccine should be given instead. It is imperative to ensure the individual is offered a suitable and available vaccine containing a pertussis-containing antigen, rather than risk not receiving a pertussis containing vaccine during pregnancy.

Single antigen pertussis vaccine

Monovalent pertussis vaccines are not available. Pregnant women requesting monovalent vaccine should be reassured of the safety and efficacy of Tdap and dTaP/IPV vaccines during pregnancy.

Vaccine administration

Tdap (ADACEL) vaccine is supplied as a 0.5 ml suspension in a pre-filled syringe with a plunger stopper. The tip caps of the pre-filled syringes contain a natural rubber latex derivative which may cause allergic reactions in latex sensitive individuals.

dTaP/IPV (Boostrix-IPV or REPEVAX) vaccine is supplied as a 0.5ml suspension in a pre-filled syringe with a plunger stopper. The tip caps are made of a synthetic form of rubber (butyl) which does not contain any dry natural rubber (latex).

Tdap and dTaP/IPV should be administered as a single intramuscular injection of 0.5ml into the deltoid region of the upper arm.

Healthcare practitioners are encouraged to read the PGD and the Summary of Product Characteristics (SmPC) prior to administration to familiarise themselves with the vaccines.

Vaccine contraindications and precautions

There are very few individuals who cannot receive pertussis-containing vaccines. The vaccines should not be administered to those who have had a:

• confirmed anaphylactic reaction to a previous dose of a diphtheria, tetanus, polio or pertussis-containing vaccine
• confirmed anaphylactic reaction to any component of the vaccine or residue from the manufacturing process, including formaldehyde, glutaraldehyde, streptomycin, neomycin, polymyxin and bovine serum albumin (refer to relevant statistical process control (SPC))
• severe allergic reaction to latex (applies to Tdap vaccine only, see section below)

Women who have an acute severe febrile illness should have their vaccine postponed until they have recovered, but they should be advised when they can be vaccinated and another appointment should be arranged (the presence of a minor infection is not a contraindication for immunisation).

Women with an unstable neurological condition, including uncontrolled epilepsy, without an identifiable cause should have their immunisation deferred to avoid incorrect attribution of any change, whilst balancing the risk of deferral against the risk of preventable infection. Vaccination should be given promptly once the diagnosis is clear, the expected course of the condition is known, or both. In both instances, a patient specific direction (PSD) must be used.

See also ‘Criteria for exclusion’ section in the PGD.

Where there is any uncertainty as to whether the pregnant woman can receive the vaccine, seek appropriate advice from the local Screening and Immunisation Team, the local Health Protection Team or the woman’s clinician where appropriate.

The risk to the woman and her infant of not being immunised must also be taken into account.

Latex allergy

The tip caps of the pre-filled syringes of Tdap (ADACEL) vaccine contain a natural rubber latex derivative which may cause allergic reactions in latex sensitive individuals.

The Green Book Chapter 6 states the following about severe latex allergy:

“It is theoretically possible that latex protein from these tip caps, plungers or vial stoppers may cause allergic reactions when the vaccines are administered to latex-sensitive individuals. There is little evidence that such a risk exists and any such risk would be extremely small ^{[footnote 12]}.

As a precaution, if an individual has a history of severe (i.e. anaphylactic) allergy to latex, vaccines supplied in vials or syringes that contain latex should not be administered, unless the benefit of vaccination outweighs the risk of an allergic reaction to the vaccine. Where possible, an alternative latex-free vaccine that covers the same disease should be administered. For latex allergies other than anaphylactic allergies (for example, a history of contact allergy to latex gloves), vaccines supplied in vials or syringes that contain latex can be administered ^{[footnote 13]}.”

Pregnant women with a known severe latex allergy should be offered one of the dTaP/IPV vaccines (Boostrix-IPV or REPEVAX) as these have a tip cap which does not contain any latex. If the dTaP/IPV vaccine is not available in the maternity services setting, a referral to primary care to receive this vaccine will be necessary.

Adverse reactions following Tdap or dTaP/IPV

The most commonly reported reactions following vaccination with Tdap and dTaP/IPV vaccines in clinical trials were local reactions at the injection site (pain, redness and swelling) headache, achiness and tiredness. Diarrhoea, nausea and vomiting were also commonly reported.

Hypersensitivity reactions and anaphylaxis can occur but are very rare. A detailed list of adverse reactions is available from the product’s SPC.

Healthcare professionals and pregnant women are encouraged to report suspected adverse reactions to the MHRA using the Yellow Card reporting scheme.

Any adverse reaction to a vaccine should be documented in the woman’s record and their GP should be informed.

Administering Tdap or dTaP/IPV vaccine at the same time as anti-D treatment

Tdap and dTaP/IPV are inactivated vaccines which will not be affected by, nor interfere with, anti-D treatment. The administration of Tdap or dTaP /IPV vaccine should not be delayed due to the individual receiving anti-D treatment.

Pregnant women previously vaccinated against pertussis in their current pregnancy

If a pregnant woman received pertussis-containing vaccine before week 16 of her pregnancy, either in error or for occupational or contact reasons, then she should be offered a second dose when she reaches 16 weeks of pregnancy or around the time of her antenatal fetal anomaly scan.

The dose should be repeated to maximise the antibodies she can transfer across the placenta to her unborn baby. If a repeat dose is required, there should be an interval of at least 4 weeks from the previous dose to minimise the risk of local reaction.

If a pregnant woman has received a dose of pertussis-containing vaccine after week 16 of pregnancy for occupational or contact reasons, this would be counted as a valid dose and she would not need a repeat dose.

Influenza vaccine and Tdap and dTaP/IPV vaccines

The seasonal influenza vaccine should be offered to women at any stage of pregnancy during the seasonal flu vaccination campaign, which is usually from September each year. Tdap (or dTaP/IPV where necessary) should be offered to women between week 16 and week 32 of pregnancy, ideally at the time of the fetal anomaly scan (at around 20 weeks) regardless of the time of year.

Both vaccines are inactivated vaccines containing different antigens and therefore may be administered at the same time or at any interval before or after each other. No minimum interval needs to be observed between these vaccines.

Both vaccines should be given at the recommended time and vaccination should not be delayed in order to reduce the number of appointments required.

COVID-19 vaccine and Tdap and dTaP/IPV vaccines

In December 2021, following the recognition of pregnancy as a risk factor for severe COVID-19 infection and poor pregnancy outcomes during the Delta wave, pregnancy (all stages) was classified as a clinical risk group for COVID-19. Pregnant women have subsequently been offered COVID-19 vaccine as part of some seasonal COVID-19 vaccination campaigns. Pregnant women with certain underlying medical conditions may be eligible during some campaigns even when other pregnant women are not.

If a pregnant woman is due to receive her pertussis-containing vaccine during a COVID-19 vaccination campaign in which she is eligible, she can receive it at the same time as, or at any interval before or after, her COVID-19 vaccine.

Further information on the COVID-19 vaccination programme can be found in the COVID-19 chapter 14a of the Green Book.

Tdap or dTaP/IPV following administration of a Td/IPV (REVAXIS) vaccine

Please also refer to Pregnant women and women presenting shortly after giving birth with an incomplete or unknown vaccination history (primary vaccination against diphtheria, tetanus and polio).

If Td/IPV vaccine has been given from the 16th week of pregnancy as part of a primary course or as a booster dose following a tetanus prone wound or exposure to diphtheria or polio, a dose of Tdap or dTaP/IPV should be given as soon as possible after this dose to reduce the risk of local reactions and so that the dose of pertussis-containing vaccine is not missed. If not given on the same day or shortly after, the woman should be advised of the increased risk of local reactions.

If the dose of Td/IPV was given as part of a primary course and the dose of Tdap or dTaP/IPV vaccine is given within 3 weeks of the Td/IPV dose, the dose of Td/IPV should be discounted because the response to the diphtheria and tetanus components may be suboptimal as there will have been an insufficient time interval between doses of these antigens to generate a full immune response. Therefore, a replacement dose and any further dose or doses of Td/IPV that are required to complete a primary course should be offered, either at the end of pregnancy or at a minimum 4 week interval from the date of administration of the pertussis-containing vaccine if the course needs to be completed without delay.

Inadvertent vaccine administration errors

Tdap or dTaP/IPV administered before 16 weeks of pregnancy

If the dose was given before 16 weeks of pregnancy, it should be repeated once the woman reaches 16 weeks of pregnancy or around the time of her fetal anomaly scan. A minimum interval of 4 weeks between doses should be observed to reduce the risk of a local reaction. Repeating the dose will ensure that the unborn baby benefits from optimal transfer of maternal antibodies.

Infanrix hexa or Vaxelis vaccine (DTaP/IPV/Hib/Hep B) administered in error

Women who have inadvertently received the 6 in 1 (DTaP/IPV/Hib/HepB) Infanrix hexa or Vaxelis vaccines instead of the recommended Tdap or dTaP/IPV vaccine should be reassured that both Infanrix hexa and Vaxelis will offer protection against pertussis and that no further action is required.

Such women should also be advised that Infanrix hexa and Vaxelis contain a high dose of diphtheria that is not normally given to adults because it is more likely to cause a localised reaction. Women who have inadvertently received Infanrix hexa or Vaxelis should be informed of the higher risk of localised reactions.

Healthcare practitioners should report the administration error via their local governance systems so that the appropriate action can be taken, lessons can be learned and the risk of future errors minimised.

Td/IPV (REVAXIS) vaccine administered in error

As Td/IPV vaccine (REVAXIS) does not protect against pertussis, a dose of Tdap or dTaP/IPV should be given as soon as possible after the error is realised, ideally on the same day to reduce the risk of local reactions and so that the dose of pertussis-containing vaccine is not missed. If not given on the same day or shortly after, the woman should be advised of the increased risk of local reactions.

Healthcare practitioners should report the administration error via their local governance systems so that the appropriate action can be taken, lessons can be learned and the risk of future errors minimised.

dTaP/IPV (REPEVAX or Boostrix-IPV) vaccine administered in error

Although the JCVI expressed a preference for Tdap vaccine to be offered to pregnant women once this vaccine became available, if a dTaP/IPV vaccine is administered in error, this should still be counted as a valid dose. The overall aim of the programme is to ensure that the woman is given a pertussis-containing vaccine in order to protect her infant from pertussis in the first few weeks of life.

Whilst studies have shown that there may be some blunting of infant’s antibody responses to polio when a polio-containing vaccine is given in pregnancy, the clinical relevance of this is unclear and the level of antibodies made is still above the protective threshold. Additionally, in future changes to the immunisation schedule, infants will routinely be boosted against polio at 18 months when an additional dose of DTaP/IPV/Hib/HepB is introduced into the routine childhood schedule.

Tdap vaccine administered as a pre-school booster vaccine in error

If Tdap vaccine (ADACEL) is administered as a pre-school booster in error instead of the dTaP/IPV vaccine that should have been administered, the child should be offered a dTaP/IPV vaccine as soon as the error is realised. This is because the Tdap vaccine will not provide protection against polio.

Healthcare practitioners should familiarise themselves with the difference between the vaccines and the vaccine packaging to minimise the risk of the error occurring again. Where possible, ADACEL should be kept in a separate part of the vaccine fridge away from the pre-school booster dTaP/IPV vaccine.

Improving vaccine uptake

The number of women receiving a pertussis-containing vaccine has fallen year on year over the last few years. For the 2022 to 2023 financial year, vaccine coverage was 60.7%. This means a large number of pregnant women are not receiving a vaccine to protect their infant at a time when the number of cases of pertussis is increasing.

Healthcare practitioners are asked to ensure that appropriate measures are in place to optimise uptake of pertussis-containing vaccine for pregnant women. These include:

• ensuring vaccine is easily accessible, for example, in the maternity clinic when the woman is already attending for another reason

• ensuring that staff have received appropriate training and supervised clinical practice so that they are informed and confident and able to answer any questions the woman may have

• providing information resources so that the women are able to access further information if they wish to, for example providing the leaflets and displaying the poster available at Whooping cough: vaccination in pregnancy programme resources - GOV.UK

It is recommended that staff responsible for implementing the pertussis in pregnancy vaccination programme look at the National Institute for Health and Care Excellence (NICE) guidance NG218 Evidence review F: interventions to increase the uptake of routine vaccines for pregnant women. It is also important to inform pregnant women that pertussis infection can occur at any point in the year and that it is not a seasonal infection in the way that influenza is. They should be offered pertussis vaccination at the appropriate point in their pregnancy all year round – it should not be delayed to the autumn and winter months to coincide with giving them the influenza vaccination.

Further information

• Immunisation against infectious diseases: Pertussis Green Book chapter 24

• Whooping cough in pregnancy programme

• Whooping cough: vaccination in pregnancy programme resources.

• The vaccine knowledge project: pertussis vaccine in pregnancy

• Summary of Product Characteristics for Boostrix-IPV

• Summary of Product Characteristic for REPEVAX

• Summary of Product Characteristics for ADACEL

• Confirmed cases of pertussis in England by month - GOV.UK (www.gov.uk)

• Pertussis: guidance, data and analysis - GOV.UK (www.gov.uk)

References

EClinicalMedicine 2019, volume 13, pages 21-30

1.  Amirthalingam G and others. Effectiveness of maternal pertussis vaccination in England: an observational study Lancet 2014: volume 384, pages 1,521-8 ↩

2. Dabrera G and others. A case-control study to estimate the effectiveness of maternal pertussis vaccination in protecting newborn infants in England and Wales, 2012-2013 Clinical Infectious Diseases 2015: volume 60, pages 333-7 ↩

3. Winter K and others. Effectiveness of prenatal tetanus, diphtheria, and acellular pertussis vaccination on pertussis severity in infants Clinical Infectious Diseases 2017: volume 64, pages 9-14 ↩

4. Campbell H, Gupta S, Dolan GP and others. ‘Review of vaccination in pregnancy to prevent pertussis in early infancy’ Journal of Medical Microbiology 2018: volume 67, issue 10, pages 1,426-1,456 ↩

5. Abu-Raya B and others. Global Perspectives on Immunization During Pregnancy and Priorities for Future Research and Development: An International Consensus Statement Frontiers Immunology 24 June 2020 ↩

6. Laverty M and others. Health Outcomes in Young Children Following Pertussis Vaccination During Pregnancy Pediatrics 2021: volume 147, issue 5, e2020042507 ↩

7. Abu-Raya and others. Vaccination in Pregnancy against Pertussis: A Consensus Statement on Behalf of the Global Pertussis Initiative Vaccines 23 November 2022 ↩

8. iMAP2 - Health Research Authority (hra.nhs.uk)  ↩

9. iMAP3 - Health Research Authority (hra.nhs.uk)  ↩

10. Zimmermann P and others. The effect of maternal immunisation during pregnancy on infant vaccine responses ↩

11. Voysey M and others. The influence of maternally derived antibody and infant age at vaccination on infant vaccine responses JAMA Pediatrics 2017: volume 171, issue 7, pages 637-646 ↩

12. Russell M, Pool V and Kelso JM and others. Vaccination of persons allergic to latex: a review of safety data in the Vaccine Adverse Event Reporting System (VAERS) Vaccine 2004: volume 23, issue 5, pages 664-7 ↩

13. Advisory Committee on Immunization Practices (ACIP). General Recommendations on Immunization Morbidity and Mortality Weekly Report (MMWR) 2011: volume 60 (RR02), pages 1-60 ↩