AstraZeneca and Catalent defend Covid vaccine manufacturing process

AstraZeneca and one of its key European suppliers have defended their Covid-19 vaccine production process after the EU drugs regulator said it was investigating whether there could have been manufacturing defects in specific batches.

The European Medicines Agency inquiry follows reports of possible side-effects, including blood clots, that have led to at least 16 European countries to suspend or limit use of the shot. The EMA has said it was unlikely the reported adverse events were connected to the vaccine or to specific batches but that a link could not yet be ruled out.

Emer Cooke, the head of EMA, said on Tuesday that the agency was investigating “the possibility or plausibility of any events linked to specific batches” of the Oxford/AstraZeneca jab, as well as “any differences in manufacturing . . . that might lead to some disparities across batches”.

AstraZeneca said each batch of its vaccine was subject to “more than 40 different quality control tests” between the laboratory and people’s arms.

“Every batch made in our supply network must meet the same exacting production and quality standards,” the company said. “Regular quality control testing is carried out at every stage of production, to ensure the production process is well controlled and results are consistently within required levels.”

In Europe, where most of the reported blood clot events have been recorded, Oxford/AstraZeneca’s vaccine is manufactured in a multi-step process.

The active ingredient or drug substance is supposed to be produced at plants including one in Belgium and one in the Netherlands. It is then shipped to so-called “fill and finish” facilities where the drug product is manufactured and put into vials.

One of AstraZeneca’s fill and finish facilities is the Anagni plant in Italy, run by US company Catalent. That plant produced two of the batches that initially triggered the suspension of vaccinations in Austria and Italy, ABV 5300 and ABV 2856.

Those batches are not being used in the UK, according to UK health officials, but they have been distributed widely across Europe.

Cooke said that an initial investigation after Austria’s suspension of the ABV 5300 batch had yielded no “plausible” link between that batch of vaccine and the reported adverse events.

“As we’re seeing more events reported across Europe we’re seeing more batches are involved,” she said. “It’s unlikely it’s a batch-specific event . . . but we cannot rule it out.”

Mario Gargiulo, the president of the European biologics division of Catalent, told the Financial Times that every batch shipped from Anagni had met rigorous quality specifications and testing.

“All documentation and quality assessments pertaining to these batches were once again reviewed by Catalent, AstraZeneca, and the Italian [drugs] regulator, AIFA,” he said. Italian regulators will inspect the plant a third time this week, officials said.

AstraZeneca’s drug substance facility at Seneffe in Belgium is run by Thermo Fisher Scientific, which declined to comment on the EMA probe. The drug substance facility at Leiden in the Netherlands, run by Halix, is yet to supply vaccine ingredients to the EU as it is awaiting EMA approval. Oxford BioMedica in the UK, which is also approved to provide drug substance for AstraZeneca in the EU, also declined to comment.

Catalent also has manufacturing sites in the US, where it fills vials for Johnson & Johnson and Moderna. Earlier this year, it had to resort to checking vials manually for J&J because of a manufacturing issue, which delayed some deliveries.

Additional reporting by Guy Chazan in Berlin, Michael Peel and Sam Flemming in Brussels, and Sarah Neville in London