TOKYO -- Takeda Pharmaceutical Co, the Japanese partner for Novavax Inc's COVID-19 vaccine, is preparing to seek regulatory approval for a roll out in Japan early next year, its top executive said on Friday.

Novavax delayed filing for U.S. approval to the end of this year, and Politico reported this month that the Maryland-based company has faced production and quality problems. The drugmaker filed for conditional authorisation to British regulators on Wednesday and with Australia's Therapeutic Goods Administration on Friday.

"We will need to assess whether the package that has been filed in the UK, for example, will satisfy the Japanese authorities," Takeda CEO Christophe Weber said in an interview ahead of the Reuters Total Health conference, which will run virtually from Nov. 15-18.

"I think this is what will happen in the coming weeks and months," he said, adding he believed it would be ready in time to help with Japan's booster shot programme, which is set to start by the end of this year.

Takeda is setting up to make the vaccines "as soon as the product is approved," he said.

Takeda has said it can make 250 million doses of Novavax's protein-based vaccine at its Hikari plant in western Japan, and has contracted to sell 150 million to the Japanese government.

Japan has largely depended on the mRNA-type shots of Pfizer Inc/BioNTech and Moderna Inc in its vaccination effort, which has fully inoculated 71% of its population.

Takeda has been a major part of that push, acting as the importer and distributor of 50 million Moderna doses this year, with contracts for the same amount next year.

COVID-19 vaccine expenditures in Japan could reach about 1.37 trillion yen ($12.1 billion) in the next five years, according to health data firm IQVIA Holdings, and Takeda has a sizable first-mover advantage.

But numerous hurdles remain. Takeda and Moderna recalled 1.63 million doses in Japan after the discovery of metal contaminants in some vials, a problem traced back to a production partner in Spain.

"Manufacturing processes are always very complex in the case of vaccines," Weber said.

"That's why there's been so many supply issues with vaccines since the beginning of COVID-19, because it's not an easy process."

($1 = 113.5900 yen)