TORONTO (Canadian Press) -- Health Canada has lifted its hold on Novartis flu vaccines.

The department has told the provinces and territories that had bought Novartis products that the vaccines are safe to use.

The decision means provinces that have either suspended their flu shot clinics or had to scramble to use vaccines made by other companies can resume normal operations.

The decision follows a risk assessment the department did using information from European regulatory agencies and the company.

Health Canada suspended use of the Novartis vaccines last Friday after several European countries stopped using two of the company's vaccines, Fluad and Agriflu.

The Italian regulatory agency had stopped distribution of Novartis vaccine to that country after the company reported finding a higher-than-normal level of protein aggregates in one batch of vaccine.

Novartis says the affected batch was pulled from distribution.

Protein aggregates are tiny bits of the killed influenza viruses that are used to make flu vaccine.

Normally those proteins are in a suspension and are not visible to the naked eye. But from time to time they fall out of suspension and can be seen.

Novartis says that's not uncommon, nor is it a sign that there is something wrong with the vaccine. Typically the particles will disappear when the vaccine is shaken, as it should be before use.

Novartis is supplying 20 per cent of Canada's total flu vaccine supply this year.

(c) The Canadian Press, 2012