TOKYO - Japan's health ministry on Tuesday approved the use of a COVID-19 vaccine developed by US pharmaceutical company Novavax to be used on people aged 18 and older.

The Novavax vaccine will mark the fourth COVID-19 inoculation approved in Japan, although will be the first protein-based vaccine compared to those developed by Pfizer and Moderna that are messenger RNA-based (mRNA) jabs.

The ministry hopes the Novavax jab can be administered to those who are likely to show allergic reactions to mRNA vaccines so they can still be vaccinated against the virus which has yet to be brought under control in Japan.

According to Japan's public broadcaster NHK, protein-based vaccines are known to cause relatively fewer reactions, with the thinking being among the ministry that this will help the uptake of those who are as yet unvaccinated because they have been worried about side effects.

The Novavax vaccine requires recipients to be jabbed twice with a three-week period between doses, the ministry said, although a third booster shot will be allowed six months or more after the second jab.

Takeda Pharmaceutical will manufacture the jab locally and distribute the Novavax vaccine and is under contract to supply 150 million doses of the vaccine to the government within a year, according to official accounts.

The rollout, they said, is expected to begin in late May, with Health Minister Shigeyuki Goto saying on Tuesday that the government purchased the vaccine last September to make sure Japan was in possession of a stable supply should restrictions be applied on overseas vaccines.

Goto also said Novavax as a vaccine also got the green light from the government specifically because it is protein-based and is regarded as safe and effective.

He added that the Japanese government had always intended to procure a variety of different vaccines so as to offer the public more choices.

Local governments have been asked by the health ministry to open at least one site where the Novavax vaccine can be administered to make sure that those who prefer the protein-based jab, or require a non-mRNA for whatever reason, have access to it.