The coronavirus vaccine booking system will be amended “in the coming days” after pregnant women were unable to access their preferred jabs.

NHS health providers – including vaccine sites, pharmacies, GP surgeries and hospital trusts – have been told by senior bosses that the system will be changed to allow pregnant women to book specific vaccines.

The change comes after a charity said pregnant women have faced confusion, delays and wasted trips in their struggle to get the vaccines they are advised to get – Pfizer-BioNTech and Moderna.

The Joint Committee on Vaccination and Immunisation (JCVI) says it is “preferable” for pregnant women in the UK to be offered the Pfizer-BioNTech and Moderna vaccines where available.

But the online booking system has not been giving pregnant women the option to specify which jab they want.

It is understood the Pfizer-BioNTech and Moderna vaccines are preferable because safety information relating to pregnant women is available for them, whereas there is not as much relevant data on other jabs such as the Oxford-AstraZeneca version.

It was confirmed on Friday that under-40s are to be offered an alternative to the Oxford-AstraZeneca vaccine.

Professor Wei Shen Lim, chairman of the JCVI, said he hopes NHS England “will be able to overcome” difficulties in pregnant women accessing the Pfizer or Moderna jabs.

He told a televised briefing: “In terms of the access to such vaccines, I understand there have been some reports of difficulties in accessing the vaccines.

“I certainly hope that operationally NHS England will be able to overcome those difficulties in access.”

He said while the JCVI advises it is preferable for pregnant women to be offered a Pfizer or Moderna vaccine, “we’re not saying that the other vaccines are in any way harmful or should not be given”.

He added: “Simply that, where it’s available, we should offer, if possible, the Pfizer or Moderna vaccines to women who are pregnant.”

A letter to health providers from senior bosses, including national medical director Professor Stephen Powis, published on Friday, said: “Following the JCVI advice that women who are pregnant or think they are pregnant should continue to be offered the Pfizer-BioNTech or Moderna vaccine, dependent on age and clinical risk, we wrote to you on 17 April advising on next steps.

“Local services should have arrangements in place to invite pregnant women to be vaccinated in a timely way, in line with the latest eligible cohorts.

“NHS Digital will be amending the National Booking Service in the coming days to allow pregnant women to book into specific vaccine appointments in line with JCVI guidance.”

Labour MP Stella Creasy had a Pfizer jab on Friday because other people did not turn up, and has been highlighting the issue, warning that there is a “backlog” of pregnant women who need a vaccine.

Ms Creasy, who is pregnant with her second child and due to give birth at the end of the summer, told the PA news agency: “There’s a lot of pregnant women who’ve been very frustrated because they’ve been pushed from pillar to post.

“And if you then realise that we’re the only group of patients who have to wait until somebody else has said no that’s why I think there’s been such a furore about it.”

Ms Creasy, 44, said she has “an inbox full” of local women who have not been able to get a vaccine through their local doctors due to doctors not necessarily knowing when the particular vaccines will be available in their clinics.

She added: “It’s like all of these questions about maternal healthcare and pregnancy – it needs to be recognised as… this is not women being difficult.

“This is an issue that has to be taken into account in service provision.”

Ms Creasy said she thinks there is movement on the issue, adding: “What we have to hope for is that from next week things might be different but until then I’m going to keep challenging on this.”

Ms Creasy revealed on Twitter that she had had a Pfizer jab on Friday, tweeting: “Because people didn’t turn up today for Pfizer vaccine, me and 12 other pregnant women in Walthamstow were able to have their leftovers at our brilliant local doctors clinic.

“We urgently need a system that works for all pregnant women and treats them as equals not afterthought!”

Ros Bragg, director of the Maternity Action charity, said earlier that she was not surprised pregnant women have found it difficult to access the preferred Covid-19 vaccine, adding that the needs of pregnant women and new mothers have been “woefully low on the Government’s priority list” throughout the pandemic.

Ms Bragg said: “Against this backdrop, we cautiously welcomed the news that the JCVI updated their guidance on pregnant women receiving certain Covid jabs.

“However the lack of clear guidance on how to access the appropriate vaccine has led to confusion among women, and has led to wasted trips, unnecessary travel and delays in getting the vaccine.”