By Bojan Pancevski and Giovanni Legorano

Tension is rising between European authorities and Pfizer Inc. and BioNTech SE after officials said the companies had unexpectedly cut their deliveries of Covid-19 vaccines and put their immunization schedules at risk.

The Italian government asked the country's attorney general to study whether it can take legal action after Pfizer cut deliveries of its vaccine for this week by 29% as it retools its Belgium factory, a government spokeswoman said Wednesday.

Separately, the German state of Hamburg said Pfizer had delivered fewer vials of vaccine to the city than expected this week.

In Europe, Pfizer and BioNTech initially shipped vials of five-vaccine doses, but because of a precautionary practice known as overfilling, the vials contained enough extra liquid for a sixth dose. After the European Union's drugs agency ruled on Jan. 8 that six doses could be obtained from a vial, the companies cut the number of vials delivered, arguing that their contract was for a certain amount of doses, not vials. The companies have said they were on schedule to deliver the number of doses they had promised.

A Hamburg government spokeswoman said the state has struggled to extract the sixth dose as special syringes are required and authorities haven't been able to purchase them in sufficient quantities. This has left their mobile vaccination teams that inoculate care homes unable to use the full amount of vaccine, she said.

Hamburg authorities said their vaccination plans relied on obtaining 10% more doses than the state will be able to extract from the vials because of the relabeling of five-dose vials into six-dose vials.

"Six vials used to be delivered for 30 vaccine doses until now, but now there are only five," said Hamburg State Health Minister Melanie Leonhard in an emailed statement. "The amounts [of vaccine] that were supposed to be delivered have been reduced."

Pfizer in a statement didn't specifically address the situations in Hamburg or Italy, but said it planned to fulfill its supply vaccine to countries in line with its agreements with governments and as permitted by regulatory authorities.

The company said its agreements were always based on delivery of doses, not vials. Pfizer and BioNTech raised their manufacturing target for this year to two billion doses in part because of the revised six-dose-per-vial label, the company said.

A spokeswoman for BioNTech declined to comment on the Italian government's allegations and said vaccine sales contracts were for doses, not vials.

Pfizer said last week that Europe would suffer a temporary shortfall in deliveries that would be offset later because of production upgrades at its Belgian factory.

The Italian government said that Pfizer first informed it of a drop in deliveries on Friday and that the company then told the government on Tuesday that there would be an additional cut next week.

"The government is worried and alarmed," the government spokeswoman said. "It deplores the company's behavior."

Pfizer unilaterally decided to cut the deliveries to some Italian regions more than others, according to Italian authorities, prompting many local administrations to complain that they were struggling to secure enough doses for the second injection, which is needed for the best immunity against the virus.

The regions that suffered smaller cuts are donating some of their doses to the most affected regions so that they can complete the second round of inoculations, the government spokeswoman said.

Other EU countries are also affected by the cuts, but none have so far said they would take legal action. A spokesman for Germany's Health Ministry said there was no legal remedy against reduced deliveries. Health Minister Jens Spahn said Wednesday that he was frustrated at Pfizer's sudden announcement last week about disruptions at its European plant.

"The problem is above all how short-notice Pfizer's announcement has been, and that is annoying," Mr. Spahn told journalists. "I understand the reasons, they have to scale up...it is good that they are expanding their capacities but it is very, very displeasing that they announced it overnight."

Separately, a German government spokesman said some states besides Hamburg were also missing the special syringes needed to extract the sixth dose from the relabeled vials. But he added that there was no legal recourse against the companies as the EU itself had declared that a vial now contains six doses.

Pfizer markets the vaccine together with their German partner, BioNTech SE. The EU has so far ordered 300 million doses from Pfizer and BioNTech, and negotiations are continuing for another 200 million shots.

--Jared Hopkins contributed to this article.

Write to Bojan Pancevski at bojan.pancevski@wsj.com and Giovanni Legorano at giovanni.legorano@wsj.com

Corrections & Amplifications

This item was corrected at 2338 GMT to show that an Italian government spokeswoman said Wednesday that the government asked the country's attorney general to study whether it can take legal action after Pfizer cut deliveries. An earlier version incorrectly gave the date as Tuesday.

(END) Dow Jones Newswires

01-20-21 1759ET