UK trial explores Covid-19 vaccine dose interval for pregnant women

August 3, 2021 (Last Updated August 3rd, 2021 11:51)

The trial will involve the vaccination of more than 600 pregnant women with Pfizer-BioNTech or Moderna Covid-19 jabs.

UK trial explores Covid-19 vaccine dose interval for pregnant women
So far, no safety concerns were reported in pregnant women vaccinated in the US and the UK. Credit: freestocks on Unsplash.

The UK Government has announced a new clinical trial to determine the best interval between Covid-19 vaccine doses for pregnant women.

Launched in England, the Preg-CoV trial is funded by £7.5m from the government and led by St George’s, University of London.

The aim is to obtain important data on the immune response to Pfizer-BioNTech or Moderna Covid-19 vaccines administered at an interval of four to six weeks or eight to 12 weeks between first and second doses.

In addition to the best dosage interval, the trial is expected to provide insights into the vaccines’ protection against Covid-19 in pregnant mothers and their babies.

A total of more than 600 pregnant women will be vaccinated as part of the trial and followed up by healthcare professionals throughout pregnancy and after childbirth.

Preg-CoV will enrol subjects aged between 18 and 44 years who are 13 to 34 weeks pregnant and have no other health concerns.

Participants will be given two doses of a vaccine, or only one dose if previously vaccinated with the first dose, either four to six weeks or eight to 12 weeks apart.

Scheduled to begin inoculations this month, the trial is anticipated to yield preliminary results by year-end. It will be carried out at 13 National Institute for Health Research (NIHR) sites across England.

University of London St George’s paediatric infectious diseases professor Paul Heath said: “Tens of thousands of pregnant women have now been vaccinated in both the US and the UK with no safety concerns reported, but we still lack robust, prospective clinical trial data on Covid-19 vaccines in pregnant women.

“We are extremely pleased to commence the Preg-CoV trial, which aims to fill these gaps in our knowledge and will ultimately inform policy recommendations on the optimal use of Covid-19 vaccines in pregnancy.”

The Joint Committee on Vaccination and Immunisation (JCVI)’s independent experts recommended the use of the Pfizer-BioNTech and Moderna Covid-19 vaccines in pregnant mothers in the UK.

This recommendation was made after no safety concerns were reported in 130,000 pregnant women inoculated in the US.

Likewise, no safety concerns were seen among 52,000 pregnant women vaccinated in England to date.

Furthermore, findings published recently by NHS England and the University of Oxford revealed no Covid-19-related hospitalisations of pregnant women who received both vaccine doses.

Only three were hospitalised following their first dose, indicating that 98% of pregnant women admitted to hospital due to Covid-19 are not vaccinated.

This June, the National Institutes of Health (NIH) of the US started a new clinical study, MOMI-VAX, to assess immune responses induced by Covid-19 vaccines in pregnant or postpartum individuals.