AZ exits US vaccine plant after mix-up spoils J&J's COVID jab

AstraZeneca is shifting production of its COVID-19 vaccine away from a plant in Baltimore which also makes Johnson & Johnson's shot, after human error resulted in the contamination of 15 million doses. 

The mix-up at the facility operated by contract manufacturer Emergent BioSolutions resulted in ingredients destined for AZ's AZD1222 jab being mixed into vials of the J&J product, rendering them unusable, according to media reports.

Emergent claims however that one batch of the vaccine simply failed quality controls, and no contamination took place. The FDA says it is investigating the incident.

Whatever the cause, AZ is now pulling out of the facility and will shift production elsewhere, while J&J says it is "assuming full responsibility" for manufacturing of the drug substance for its vaccine at the plant.

Shares in Emergent fell around 15% after news of the spoiled doses emerged, with J&J also dipping marginally despite its assertions that it expects to deliver nearly 100 million doses of its single-shot vaccine to the US Government by the end of next month.

AZ's vaccine isn’t yet approved for use in the US, but the company says it is working on a regulatory submission for the shot and is working with the government to "identify an alternative location for domestic drug substance production of AZD1222".

The Emergent plant has not yet been given emergency authorisation to supply the US market, but the wastage of J&J's vaccine is a nevertheless hit to the US's vaccination programme.

According to a New York Times report, the government ordered the plant to stop making the AZ vaccine to avoid any future mishaps and safeguard future supplies of the J&J jab.

Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases (NIAID), has also suggested that the US may not need the AZ COVID-19 vaccine because contracts with other suppliers are sufficient to vaccinate the entire population.

Immunisation in the US stepped up a gear recently with daily doses averaging around 2.9 million, and 40% of US adults having received at least one dose. President Biden has pledged to deliver 200 million doses in his first 100 days in office, and that tally currently stands at 148 million.

A White House spokesman said that the issue at the Baltimore plant does not affect any J&J doses that have been distributed, as all J&J finished doses to date have been produced in a different, FDA-approved facility.

"Importantly, we are on track to have enough vaccine supply for all adult Americans by the end of May," he added. The US has had more than 31 million cases of COVID-19, with deaths approaching 570,000.

There are also fears that news of the accident could undermine public confidence in vaccination at a time when AZ's shot in particular is coming under scrutiny over a link to blood clot.

The UK's Medicines and Healthcare products Regulatory Agency (MHRA) has said it has identified 30 blood clot cases out of 18 million people vaccinated with AZD1222 by 24 March – including 22 cases of cerebral venous sinus thrombosis (CVST) associated with low platelet counts – with seven deaths.

The agency says there is still no indication these cases are linked to the vaccine, and that the benefits of the shot outweigh any risk, in line with announcements from the EU medicines regulator and World Health Organization (WHO) last week.