Scientists charged with checking the chemicals sent to the bloc for approval last year found doses were of a lower standard than the US drugmaker had promised.
In an email dated November 23, a senior European Medicines Agency official warned of a ‘significant difference’ in the quality of the vaccines compared to jabs used in Pfizer’s clinical trials.
The cause of the poorer quality was unknown and the impact on safety and efficacy of the vaccine was ‘yet to be defined’, the email said. Pfizer claims the affected jabs were not rolled out on the continent.
It’s unclear if similar quality issues were raised in the UK, where the Pfizer jab is one of two vaccines that has been rolled out to 23million Brits already. Regulators in the EU and UK check every batch of the vaccine before allowing them to be used.
On the back of the find, EU officials filed two ‘major objections’ to Pfizer, along with a host of other quality control questions it wanted addressed, before it could approve the vaccine.
The documents were leaked to the British Medical Journal (BMJ) following a cyber attack on the EU regulator in December.
Hundreds of thousands of doses of Pfizer’s Covid-19 vaccine being prepared in a factory in Belgium (file image)
While the reason behind the poorer quality of vaccines sent to the EU is unclear, Pfizer’s jab is made from extremely volatile genetic material known as messenger RNA (mRNA), which at the time meant it had to be kept at -70C.
If not stored or transported properly the mRNA can be damaged by other molecules in the environment, including light and temperature.
Guidance has since been updated to say the vaccine can be kept at normal freezer temperatures for two weeks. Once it arrives at a clinic it can be stored in a fridge for five days before use.
WHAT IS MRNA AND WHY IS PFIZER’S VACCINE PRONE TO ‘SPOILING’?
The breakthrough jab — shown to be 95 per cent effective at blocking Covid-19 — was the first vaccine against the virus in the world to seal approval when Britain gave it the green light in December.
It is made from volatile genetic material known as mRNA, which is constantly under threat from being destroyed by other molecules in the environment.
BioNTech packages the vaccine in dry-ice stuffed batches of 975 vials, each containing five doses, which must be stored at -70C to stop the mRNA being destroyed in transit or storage.
Messenger RNA is used by human cells to carry messages and give instructions. Pfizer’s jab tells the body to create the coronavirus’s unique spike protein, training the immune system to recognise and fight off future infection.
But, as a result of the natural rapid turnaround of mRNA’s lifespan, it is, by nature, a short-lived molecule only ever intended to exist for a matter of hours.
This poses a significant problem when trying to get the mRNA vaccine into a human as under normal conditions it will break down and become useless.
There are not many proven ways of ensuring long-term survival of the vaccine. One proven method is extremely cold temperatures, which stops all movement and reactions and prevents any form of decomposition of the mRNA. However, the vaccine must be administered at room temperature because the mRNA needs to be mobile.
If left out for too long before being injected, the vaccine gets too warm, and this begins the natural decay of the mRNA. If this is then injected into a person, it will not work properly, the body will not make the spike protein and there will be no immune response. That person will still be vulnerable to Covid-19.
Light, as well as temperature, can give the mRNA molecule energy, also speeding up the already fast process of decay. To preserve Pfizer’s vaccine, it needs to be stored at super-low temperatures of about -70C (-94F) and kept in dark glass vials to shield it from light.
These precise conditions must be maintained throughout the vaccine’s journey and, once taken out of the freezer and thawed, it can only be kept in standard medical fridges for five days before ‘spoiling’.
Makers of the jab warn it only be in transport at normal fridge temperatures for a maximum of six hours, because it’s feared movement in warmer conditions breaks down the vaccine even quicker.
The EMA found just 55 per cent of the mRNA in the vaccines shipped to the EU were stable and intact, compared to 78 per cent in Pfizer’s studies.
Exactly what effect this has on the vaccines is unclear, but intact mRNA is essential to the potency of the vaccine, experts say.
The EMA approved Pfizer/BioNTech’s vaccine on December 21 and claimed the jab’s quality was found ‘to be sufficiently consistent and acceptable’.
However, it’s unclear how the agency’s concerns were satisfied.
According to one of the leaked emails dated November 25, an EMA official said: ‘The latest lots indicate that % intact RNA are back at around 70-75 per cent, which leaves us cautiously optimistic that additional data could address the issue.’
The emails were part of more than 40 megabytes of classified information from the agency’s review that were published on the dark web following the cyber attack.
Several journalists — including from the BMJ — and academics worldwide were sent copies of the leaks.
They came from anonymous email accounts and most efforts to interact with the senders were unsuccessful.
None of the senders revealed their identity, and the EMA says it is pursuing a criminal investigation.
In a statement issued last night, the EMA said the leaked information was partially doctored but it confirmed the emails were real.
It added: ‘Whilst individual emails are authentic, data from different users were selected and aggregated, screenshots from multiple folders and mailboxes have been created, and additional titles were added by the perpetrators.’
A Pfizer spokesperson told MailOnline the quality issues were ironed out with the EMA and none of the vaccines of concern were rolled out on the continent.
It added that the EMA now double-checks Pfizer’s vaccine supply shipments.
They added: ‘Following the initial disclosure of a data breach that occurred at EMA, some documents relating to the EMA’s rolling review of the Pfizer/BNT vaccine clinical program have been found on the internet.
‘Discussions with the regulatory authorities about the vaccine’s quality aspects, including specifications, represent a normal component of the regulatory review process.
‘All the topics that emerged during the procedure have been discussed transparently with the agency, in accordance to the normal practices, and all questions have been duly addressed during the review process.
‘The positive opinion granted by EMA… on December 21… are results of this process, meaning that all the questions raised during the procedure were addressed satisfactorily and the efficacy, safety and quality of the vaccine could be demonstrated on the data submitted.
‘EMA is conducting a full investigation into the cyberattack on its systems.
‘It’s important to note that each batch of vaccines is tested by the official medicinal control laboratory (OMCL) – the Paul-Ehrlich Institute in Germany – before final product release.
‘As a result, the quality of all vaccine doses that are placed on the market in Europe has been double tested to ensure compliance with the specifications agreed upon with the regulatory authorities. Should a batch not meet these required specifications, the product wouldn’t be released for use in Europe.
‘As with all vaccines, equivalent quality controls are in place with the U.S. FDA and multiple other regulators around the world where the vaccine has been authorised for use.’
The leaks raise questions about the quality of other mRNA vaccines, including Moderna’s jab which is already being rolled out in the US and will be shipped to Britain sometime in the coming weeks.
Pfizer and Moderna have refused to reveal what percentage mRNA integrity they consider acceptable for vaccines against Covid.
The EMA, US Food and Drug Administration (FDA) stated that specific information on criteria is confidential.
And the UK Medicines and Healthcare products Regulatory Agency has yet to respond to MailOnline’s request for comment.
Pfizer also declined to comment on what percentage of mRNA integrity it is aiming for, nor would it say what may have caused quality dips in certain batches.
The lack of transparency from regulators and vaccine makers will raise concerns that similar problems could arise in the future.
Professor Daan Crommelin, a pharmaceutical expert at Utrecht University in the Netherlands, said there is a lack of understanding about the percentage of intact mRNA needed because it is a brand-new technology.
He added: ‘For small, low molecular weight products, the active pharmaceutical ingredient integrity is typically close to 100 per cent.’
‘But for mRNA vaccines? Experience with mRNA integrity is limited.’
Unlike traditional jabs which scientists have decades of experience in developing, this is the first time mRNA has ever been used in vaccinations.
Scientists say mRNA vaccines are cheaper to make and easier to modify in the face of new variants or viruses.
The process of developing mRNA vaccines is also purely synthetic, meaning scientists don’t have to rely on cells from living animals.
Siu Ping Lam, MHRA Director of Licensing, said: ‘The observations of lower levels of RNA integrity with certain early batches have been addressed, and are not an ongoing concern.
‘We are satisfied that the RNA integrity of all batches used in the UK to date have met the product requirements.’