Delineating late foetal systemic and lung immune responses following vaccinations against respiratory pathogens given during pregnancy

Vaccines given in pregnancy are an exciting strategy to help protect babies in the first four weeks of life against infections. Whilst vaccines can be given to children at 3 months, the time when they are most vulnerable is the first month of life. However, in the first month of life babies cannot generate a sufficient response to most vaccinations. To overcome this, vaccines given to mothers are used to provide baby with a degree of immunity at birth. Despite 3 vaccines against lung infections (against flu, whooping cough, and COVID-19), routinely recommended in pregnancy by the Royal College of Obstetrics and Gynaecology in the UK, with no safety concerns, uptake is low, and particularly poor for newer vaccines. Part of the vaccine hesitancy stems from concerns that the vaccine may not benefit the foetal immune system or harm the baby. It is also difficult to develop new vaccines as our understanding of the foetal immune system in the last stages of pregnancy is extremely poor.

There is difficulty in studying the immune system of the unborn child. Sometimes pregnancies are terminated in late pregnancy because the baby has a severe, life-limiting problem. My study will take healthy samples from these unborn children in order to study the immune system of the blood and lung. My study will use cutting edge technology to study the types of immune cells, their function and how they are influenced by maternal vaccines.

Sepsis is a leading cause of death and morbidity in neonates, and maternal vaccination offers a potential solution to reduce this burden. However, the development of novel vaccines has been hindered by a lack of information on the impact of the vaccine on the foetal immune system.

My aims are: 1) To discover mechanisms of late foetal immune maturation and compare the maternal and foetal cellular immune populations. 2) To compare the T and B cell blood immune repertoire and function from foetuses from SARS-CoV-2, Influenza, and Tdap vaccinated versus unvaccinated mothers. 3) To analyse the foetal lung immune system from those born to SARS-CoV-2, Influenza and Tdap vaccinated versus unvaccinated mothers.

My overall objective is to comprehensively characterise the immune differences over the late stage of foetal development and the impact of antenatal vaccination.