Major concerns have been raised about the quality of early batches of Pfizer coronavirus vaccine, documents from the EU health regulator have revealed.
The scientists in charge of checking the chemicals sent in bulk for approval last year found that the doses were lower than the American doctor had promised.
In a November 23 email, a senior European Medicines Agency official warned of a “significant difference” in vaccine quality compared to jabs used in Pfizer clinical trials.
The cause of poorer quality was not known, and the impact on vaccine safety and efficacy was “still to be defined,” the e-mail said. Pfizer claims that the affected blows were not fired on the mainland.
It is unclear whether similar quality issues have been raised in the UK, where the Pfizer booster is one of two vaccines already launched to 23 million Britons. EU and UK regulators check each batch of vaccine before allowing their use.
Following the discovery, EU officials filed two “major objections” to Pfizer, along with a number of other quality control questions they wanted to ask before they could approve the vaccine.
The documents were released to the British Medical Journal (BMJ) following a cyber attack on the EU regulator in December.
Hundreds of thousands of doses of Pfizer Covid-19 vaccine are prepared in a factory in Belgium (file image)
While the reason for a lower quality of vaccines sent to the EU is unclear, Pfizer’s cage is made of highly volatile genetic material known as messenger RNA (mRNA), which at the time meant that it had to be kept at -70C.
If not stored or transported properly, mRNA can be damaged by other molecules in the environment, including light and temperature.
The guidelines have since been updated to say that the vaccine can be kept at normal freezer temperature for two weeks. Once in the clinic, it can be stored in the refrigerator for five days before use.
The EMA found that only 55 percent of mRNAs in vaccines shipped to the EU were stable and intact, compared with 78 percent in Pfizer studies.
Exactly what effect this has on vaccines is unclear, but intact mRNA is essential for vaccine potency, experts say.
The EMA approved the Pfizer / BioNTech vaccine on December 21 and claimed that the quality of the jab was found to be “sufficiently consistent and acceptable”.
However, it is not clear how the agency’s concerns were met.
According to one of the emails released on November 25, an EMA official said: “The latest batches indicate that% of intact RNA returns to around 70-75%, which leaves us cautiously optimistic that additional data could address problem”.
The emails were part of more than 40 megabytes of classified information from the agency’s review, which were published on the dark web following the cyber attack.
Several journalists – including from the BMJ – and academics from around the world received copies of the leaks.
They came from anonymous email accounts, and most efforts to interact with senders were unsuccessful.
None of the shippers has revealed their identities, and the EMA says it is pursuing a criminal investigation.
In a statement last night, the EMA said the leaked information had been partially examined, but confirmed that the emails were real.
He added: “Although individual emails are authentic, data from different users has been selected and aggregated, screenshots have been created from multiple folders and mailboxes, and additional titles have been added by perpetrators.”
A Pfizer spokesman told MailOnline that quality issues had been resolved with the EMA and that none of the vaccines of interest had been released on the continent.
He added that the EMA is now double-checking Pfizer vaccine deliveries.
They added: “Following the initial disclosure of a data breach that occurred at the EMA, some documents related to the ongoing review of the EMA of the Pfizer / BNT vaccine clinical program were found on the Internet.
“Discussions with regulators on quality aspects of the vaccine, including specifications, are a normal part of the regulatory review process.
“All issues that arose during the procedure were discussed in a transparent manner with the Agency, in accordance with normal practice, and all questions were properly addressed during the review process.
“The positive opinion given by the EMA … on 21 December … is the result of this process, which means that all the questions raised during the procedure have been satisfactorily addressed and the efficacy, safety and quality of the vaccine could be demonstrated on data sent .
“EMA is conducting a full investigation into the cyber attack on its systems.
“It is important to note that each batch of vaccines is tested by the official drug control laboratory (OMCL) – the Paul-Ehrlich Institute in Germany – before the final release of the product.
“As a result, the quality of all vaccine doses that are placed on the market in Europe has been tested twice to ensure compliance with the specifications agreed with the regulators. If a batch does not meet these required specifications, the product will not be released for use in Europe.
As with all vaccines, equivalent quality controls are in place with the US FDA and other regulators around the world, where the vaccine has been authorized for use.
The leaks raise questions about the quality of other mRNA vaccines, including the Moderna jab, which is already launched in the US and will be shipped to the UK sometime in the coming weeks.
Pfizer and Moderna declined to disclose what percentage of mRNA integrity they consider acceptable for Covid vaccines.
The EMA, the US Food and Drug Administration (FDA) has stated that the specific information on the criteria is confidential.
The UK Medicines and Medicines Regulatory Agency has not yet responded to MailOnline’s request for comment.
Pfizer also declined to comment on the percentage of mRNA integrity it was pursuing, nor would it say what could have caused a decrease in quality in certain batches.
The lack of transparency on the part of regulators and vaccine manufacturers will raise concerns that similar problems may arise in the future.
Professor Daan Crommelin, a pharmaceutical expert at Utrecht University in the Netherlands, said there was a lack of understanding about the percentage of intact mRNA needed because it was a new technology.
He added: “For small, low molecular weight products, the integrity of the active pharmaceutical ingredient is usually close to 100%.”
What about mRNA vaccines? Experience with mRNA integrity is limited.
Unlike traditional jabs that scientists have decades of developmental experience, this is the first time mRNA has ever been used in vaccinations.
Scientists say that 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, which means that scientists do not have to rely on cells from living animals.
Siu Ping Lam, director of MHRA licensing, said: “Observations of lower levels of RNA integrity with certain early batches have been addressed and are not a permanent concern.
“We are pleased that the RNA integrity of all batches used in the UK has so far met the product requirements.”