(Bloomberg) -- The mysterious boom in Italian exports to China is linked to Pfizer Inc.’s plant producing the anti-Covid drug Paxlovid.

The antiviral drug is manufactured in the central Italian city of Ascoli Piceno, in the Marche region. The plant was picked by the US pharma giant to produce Paxlovid for the global market along side two other sites in Germany and Ireland, according to a spokesman for Pfizer. 

Last year, Pfizer’s Italian plant reported an export value linked to Paxlovid for about €8.5 billion ($9.2 billion). At the end of 2022, the plant signed a deal with Chinese authorities to provide Paxlovid for China’s market, the spokesman added. In the first quarter Pfizer sold about 5 million pieces of Paxlovid to China, for a value equal to about €3 billion, he said.

Showing the complexity of global supply chains for pharmaceutical goods and other high-tech products, the Chinese trade data doesn’t show such a huge spike from Italy, but does show a big jump in drug imports from Ireland, one of the other production sites. Chinese imports of drugs from Ireland rose almost 650% in April to $1.2 billion after a 100% increase in March, data released this month shows. In contrast, shipments from Italy last month were worth $240 million.

Last year Pfizer invested about €40 million for new machinery in the in the Ascoli Piceno, plant hiring 200 new workers for a total of about 1,000, the spokesman added. Ascoli Piceno is one of the primary packaging plants for Paxlovid, a spokesman for Pfizer in Asia said.

READ MORE: Italy’s Exports to China Are Booming and It’s Not Clear Why

The value of Italy’s exports to China have tripled in little more than a year surpassing €3 billion in February. But the effect of Pfizer medicine almost faded in March causing a €1.2 billion drop in exports compared with the month before.

Paxlovid exports also caused a record high in the average price of pharmaceuticals exports to China, which in February surpassed 4,000 euros per kilogram, the highest since Jan. 1988 when Eurostat series started.

Paxlovid is just one of the medical treatments helping Pfizer keep its financial resilience since the end of the pandemic. Alongside Pfizer’s Covid vaccine Comirnaty, Paxlovid transformed the company, contributing more than half its $100 billion in sales in 2022.

--With assistance from James Mayger.

©2023 Bloomberg L.P.