The uptake of pertussis vaccination in pregnancy is at its lowest in 7 years, according to an alert issued by the UK Health Security Agency (UKHSA). The agency said that the low vaccine update increased the risk of infants catching whooping cough.
UKHSA's latest figures showed that in 2022 average vaccine uptake among pregnant women across England had dropped to 61.5%, down from 67.8% in 2020- 21 and the lowest level since 2016.
Vaccine in Pregnancy Can Protect the Infant for the First 8 Weeks of Life
The current campaign to vaccinate women in pregnancy, ideally between weeks 16 and 32, is based on the idea that vertical transmission of immunity from the mother, passed through the placenta, should protect the infant until the routine childhood vaccination programme kicks in at 8 weeks of age.
Dr Gayatri Amirthalingam, consultant epidemiologist at UKHSA said: "Whooping cough can be very serious for young babies, particularly under 6 months, and can lead to pneumonia, permanent brain damage, and even death. That's why it's so important that all expectant mothers get the vaccine at the recommended time from 20 weeks, to give their babies the best protection from this serious and highly contagious disease."
As there is no single component monovalent pertussis vaccine available, women are given the combined quadrivalent vaccine that contains acellular Bordetella pertussis along with diphtheria and tetanus toxoids, and inactivated poliovirus.
Vaccination Recommended Irrespective of Previous Vaccine Status
The current supply is usually Boostrix IPV (GSK), a switch from the previous Repevax vaccine; the UKHSA said that the two were "equivalent" and "either of these vaccines can be used for this vaccination programme". dTaP/IPV is supplied as a 0.5-ml dose in a pre-filled syringe and should be administered as a single intramuscular injection into the deltoid region.
The NHS recommends that pregnant women get vaccinated irrespective of their own vaccination status from childhood or vaccination during a previous pregnancy.
The UKHSA explained: "Although most women will have been vaccinated or exposed to natural whooping cough in childhood, if they are given pertussis-containing vaccine from week 16 of pregnancy, the vaccine will temporarily boost their antibody levels."
Their neonates are still recommended to have the 6-in-1 jab, which also contains hepatitis B and Haemophilus influenzae type b (Hib), at 8, 12, and 16 weeks old.
The maternal whooping cough vaccine programme was introduced on the recommendation of the Joint Committee on Vaccination and Immunisation (JCVI) as a temporary measure in 2012, following a cyclical peak in confirmed cases of pertussis infection towards the end of 2011 that continued into 2012 – the largest pertussis outbreak for over a decade.
'Emergency' Programme Continues
Although the greatest case numbers were among adolescents and young adults, the highest rates of morbidity and mortality occurred in infants less than 3 months old, with 14 infant deaths reported in England and Wales. Rates have fallen since 2012, though the JCVI recommended in 2014 that the emergency vaccination programme continue for at least a further 5 years, and said in 2019 that it should continue as a routine programme.
The UKHSA said that a study published last year found that maternal vaccination provided 89% protection against hospitalisation and 97% protection against death from whooping cough among babies born to vaccinated mothers.
The NHS said: "Pertussis-containing vaccine (whooping cough vaccine) has been used routinely in pregnant women in the UK since October 2012, and the Medicines and Healthcare products Regulatory Agency (MHRA) is carefully monitoring its safety."
It reassured the public: "There's no evidence to suggest that the whooping cough vaccine is unsafe for you or your unborn baby," citing a 2014 observational study in the BMJ that found "no evidence of risks to pregnancy or babies" in terms of stillbirths or adverse events during pregnancy following third trimester vaccination.
Coverage Especially Low in London
The 2022 data from the programme showed that uptake of the vaccine by pregnant women had dropped by 3.9% since 2021 and by 7.6% from 2020. Coverage in London was particularly low at 41.4%, the Agency said – it was 11.5 percentage points lower in December 2022 compared with December 2020, and 23.1 percentage points lower than in December 2019 [SM2] . Coverage was now 29 percentage points lower than the region with the highest coverage, North East and Yorkshire.