Johnson & Johnson is planning to ask US federal regulators this week to authorize a booster shot of its Covid-19 vaccine, the New York Times reported on Monday, citing officials familiar with the company's plans.

While scientists are divided over the need for booster shots when so many people in the United States and other countries remain unvaccinated, the Biden administration announced the push for an extra dose in August as part of an effort to shore up protection against the highly transmissible Delta variant.

The US Food and Drug Administration (FDA) last week scheduled an October 15 meeting of its expert advisory committee to discuss whether to grant emergency use authorization for a booster shot of J&J's vaccine.

Over 15 million Americans have received J&J's vaccine, which is administered as a single dose, according to the latest data from the Centers for Disease Control and Prevention.

The healthcare conglomerate last month said an additional second shot of its vaccine given about two months after the first increased its effectiveness to 94%, compared with 70% protection with the single dose.

J&J declined to comment on the NYT report and pointed to its press release dated September 21, saying the company has submitted available data to the US health regulator and intends to submit the data to other regulators.

The FDA has already authorized a booster dose of the Pfizer and partner BioNTech vaccine for those 65 and older, people at high risk of severe disease and others who are regularly exposed to the virus.

Rival Moderna also submitted its application seeking authorization for a booster shot of its two-dose vaccine last month and FDA's Vaccines and Related Biological Products Advisory Committee panel will hold a meeting on October 14 to discuss the additional dose.