A former vice-president of respiratory research at Pfizer has controversially highlighted what he describes as a potential risk that company’s vaccine will cause infertility in women.

Importantly, he does concede that there is “no indication” that such an outcome is likely, but on the basis that it is a risk, he has called for the trial to be suspended on human volunteers and re-focused on animals.

Dr. Michael Yeadon’s claim will be hotly disputed by Pfizer, who have previously stated that “an independent, external data monitoring committee has not observed any serious safety concerns” with the vaccine, and that it has already been approved by Britain’s Medicines and Healthcare Products Regulatory Agency.

Although Yeadon was a Pfizer employee, he has not worked with the company for almost a decade, and had no involvement in the development of the vaccine.

He was joined by lung specialist Dr. Wolfgang Wodarg in filing an application with the European Medicine Agency (EMA) calling for the suspension of the BioNtech/Pfizer vaccine study until a suitable study design is found which addresses their safety concerns.

The pair assert that a key protein, Syncytin-1, needed for the formation of placenta in pregnancy could be affected by an immune response to spike proteins of SARS-CoV-2 in the female body after vaccination, potentially causing infertility for an unspecified duration.

“There is no indication whether antibodies against spike proteins of SARS viruses would also act like anti-Syncytin-1 antibodies,” they write.

“However, if this were to be the case this would then also prevent the formation of a placenta which would result in vaccinated women essentially becoming infertile.”

The United Kingdom became the first Western nation to approve a Covid-19 vaccine, a landmark moment for Pfizer in producing the novel mRNA vaccine.

The first doses will be administered tomorrow in NHS hospitals, with their English medical director warning it will be the largest and most complex vaccination campaign in the country’s history.

“It will take many months for us to vaccinate everybody who needs vaccination,” Prof. Stephen Powis told Sky News.

Due to limited data on the efficacy of the vaccine on children, pregnant women, and those hoping to become pregnant within three months, the Scottish chief medical officer announced last week that those groups should not take the Pfizer injection, with other countries likely to follow suit until sufficient data becomes available.