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Pregnant women in the West Midlands called upon for Covid-19 vaccine study

A national COVID-19 vaccine study is urging pregnant women across the West Midlands to step forward and help researchers discover the most effective use of vaccines during pregnancy to protect women and their babies against COVID-19. To identify the best interval between vaccine doses, during and following pregnancy, more volunteers are urgently needed to join the Preg-CoV study.

Run at Heartlands Hospital in Birmingham and the Princess Royal Hospital, Telford, the study compares vaccines currently being used for the UK vaccination programme (Pfizer/BioNTech and Moderna) as well as new vaccines as they are approved. The NIHR-supported study will provide vital clinical trial data on the immune response to vaccination at different dose intervals - either four to six weeks or eight to 10 weeks.

Hundreds of pregnant women are needed in order to help provide further findings key to protecting more women and shaping future vaccine guidelines. The study launched in August 2021, and will involve 600 pregnant women, across 14 NIHR-supported sites across England. Volunteers will be closely monitored by health professionals throughout their pregnancy and following the birth.

Raj Watts, Research Midwife at Birmingham Heartlands Hospital said: “Our patients have really appreciated the chance to contribute to Covid research. They have been on board with the vaccination programme and we are pleased to offer them the opportunity to take part in this study to improve safety of themselves and their babies.”

- 20% of the most critically ill COVID-19 patients are unvaccinated pregnant women

- The Preg-CoV Study is comparing the use of different approved vaccines and boosters, at different schedule intervals for pregnant women

- It will provide robust data that could shape national and international guidelines

- Participants are closely monitored and will have a 24hr phone line to their study team

The current UK guidance is that COVID-19 vaccination should be offered to pregnant women at the same time as the rest of the population. COVID-19 vaccines are safe and effective for pregnant women, and there is a clinical consensus that it is the best way to protect you and your baby from COVID.

Data from UKHSA showed that over 84,600 pregnant women have received the first dose of the life-saving COVID-19 jab, and around 80,700 have received their second dose.
However, further pregnancy-specific research is currently happening in the UK to provide more data around the most effective vaccines, and the best gap between vaccine doses for pregnant women.

Chief Investigator and Professor of Paediatric Infectious Diseases at St George's, University of London, Professor Paul Heath said:

“Over two hundred and fifty thousand pregnant women have now been vaccinated with COVID-19 vaccines in both the US and the UK, with no major safety concerns reported. But we do not yet know the best schedule to use to provide the maximal protection for pregnant women against COVID-19 and this is what we are addressing in this study.

“We need even more pregnant women across the country to join the study. Not only will they receive special monitoring and support around their vaccines, but they will help shape future guidelines and protect pregnant women in the future. It is a really worthwhile, helpful thing to do.”

Pregnant women in the study will receive monitoring and additional support through study visits, compared to those who receive their vaccine outside of the study. They will also be provided a 24 hour phone line should they have any questions for the trial team and an electronic diary to record any symptoms. They will also be reimbursed for travel to their study appointments.

Recent data shows 1 in 5 of the most critically ill COVID-19 patients are pregnant women who have not been vaccinated.

Once successfully enrolled, most participants will be randomised to receive two doses of an approved COVID-19 vaccine with either a short-time interval (4-6 weeks) or a long-time interval (8-10 weeks) between doses, with the majority of volunteers blinded to which vaccine they receive.

For some participants this means they will receive their second dose after delivery. Participants will receive a single dose if they have already received their first dose or if they just need a booster (3rd) dose). All participants and their babies will be followed up until one year after delivery.

The study is seeking low-risk, carrying a single baby, pregnant women aged 18-45 years-old and between 13-34 weeks gestation. It is also recruiting participants who have already had two doses of a COVID-19 vaccine in the community.

If you are interested in the study, or know someone who could be eligible, you can find out more by visiting the study’s website.


For interviews with the lead investigators at Heartlands Hospital, please contact:

For all other media queries, please contact the NIHR Press Office: or 020 3328 6730

Notes to Editors

The Preg-CoV study is supported by the National Institute for Health Research (NIHR) and backed by over £7 million of government funding

It is led by researchers at St George’s, University of London.

Data from over 100,000 covid vaccinations in pregnancy in England and Scotland, and a further 160,000 in the US, show there has been no subsequent harm to the foetus or infant.

UK Health Security Agency (UKHSA) (PHE) publishes figures for vaccine uptake in pregnant women every 4 weeks in its weekly surveillance reports. The latest figures were published in week 43 (page 9).

Following 160,000 pregnant women being vaccinated in the US and no safety concerns being raised, the Pfizer/BioNTech and Moderna vaccines were recommended by the independent experts at the Joint Committee on Vaccination and Immunisation (JCVI) for pregnant women in the UK. As of the end of September, over 84,000 pregnant women in England have now been given their first vaccine, with over 67,000 fully vaccinated - similarly, with no safety concerns.

Sites list

Lead site: St George’s Hospital, London
Birmingham Heartlands Hospital
Princess Royal Hospital, Telford
Liverpool Women’s Hospital
Leeds General Hospital
Milton Keynes University Hospital
Royal Free Hospital, London
Royal Cornwall Hospital, Truro
Royal Preston Hospital
St Mary’s Hospital, Manchester
St Michael’s Hospital, Bristol
St Helier Hospital, London
Southampton General Hospital
Queens Charlotte’s & Chelsea Hospital (Imperial College Healthcare NHS Trust)

Why pregnant women are still needed for COVID-19 vaccine studies

Ongoing global studies so far have found that pregnant women are more likely to develop severe COVID-19 disease compared to non-pregnant women of the same age. Pregnant women who develop COVID-19 symptoms are two to three times more likely to have their baby early. Pregnant women with COVID-19 also have a higher mortality rate than pregnant women without COVID-19.Pregnant women can and should get vaccinated now. It is the best way to protect them and their baby. However, further pregnancy-specific research is needed on COVID-19 vaccines to work out how to optimise that protection.

What is this trial aiming to find out?

The trial compares vaccines that are currently being used for the UK vaccination programme, as well as new vaccines as they are approved. Low-risk pregnant women aged 18-45 years-old and between 13-34 weeks gestation can be considered for enrolment onto the study.

Once successfully enrolled, participants will be randomised to receive two doses of a COVID-19 vaccine in a short-time interval (4-6 weeks) or a long-time interval (8-10 weeks). For some participants this means they will receive their second dose after delivery. For participants who have already received one dose in the community they will be offered a 2nd dose in the study. For participants who have already received two doses in the community and are eligible for a booster dose, this will be offered in the study.

The majority of participants will be blinded to the vaccine they receive.
Some participants will also be blinded to the interval between doses by incorporating the pertussis (whooping cough) vaccine into the trial schedule. Participants will be followed up until one year after delivery.

Blood samples will be taken from participants throughout the study. For some participants, a cord blood sample will be taken after delivery. For all participants, a baby blood sample will be taken between 4 and 12 weeks of age. Participants will be asked to complete a symptom diary and any significant medical events will be investigated. For a sub-group of participants breastmilk samples will also be collected.

The study is also recruiting participants who have already had two doses of COVID-19 vaccine in the community. They will have all the same blood tests as the other participants.


Results of the trial will be disseminated in peer-reviewed scientific journals, internal reports, conference presentations and online publications.

What's next?

If you would like to find out more, please read the Study Information Booklet and if you are interested in taking part, please complete our pre-screening questionnaire.

Approximately 2 in 3 pregnant women with COVID-19 will have no symptoms, and those pregnant women who do have symptoms will usually have mild symptoms. However, a small number of pregnant women can become unwell with COVID-19, with the risk of severe illness being greater in the third trimester. Compared to non-pregnant women with COVID-19, pregnant women with COVID-19 have higher rates of intensive care unit admission and compared to pregnant women without COVID-19, pregnant women have overall worse maternal outcomes.
The studies have also found that women from black, Asian and minority ethnic backgrounds are more likely than other women to be admitted to hospital for COVID-19.

Other risk factors that increase the chances of pregnant women developing severe COVID-19 disease and requiring hospital admission are being aged 35 years and over, having a body mass index (BMI) of 25 or more and having health conditions such as high blood pressure and diabetes.

The risk of developing severe illness with COVID19 in pregnancy has also been shown to be increased in women living in areas or households with increased socioeconomic deprivation.

By performing this trial, we aim to gather further specific data on the safety of COVID-19 vaccines in pregnant women and their babies, to add to the already clear data that the vaccine is safe in pregnant women. We will also compare the immune responses to different COVID-19 vaccines in pregnant women and their babies and look at whether the stage of pregnancy and the intervals between vaccine doses makes a difference.

What vaccines are being used in this trial?

Currently, the COVID-19 vaccines that are to be studied in this trial are:

- Pfizer/BioNTech BNT162b2 – hereafter referred to as Pfizer
- COVID-19 Vaccine Moderna – hereafter referred to as Moderna
- Novavax NNVXCoV2373 – hereafter referred to as Novavax (will ONLY be used in trial when it is approved for use in the UK)
 - AstraZeneca ChAdOx1 nCOV-19 – referred to as AstraZeneca (will ONLY be use for participants who have received one dose of the vaccine already (pre-trial) and are in Cohort 4