A panel of expert advisers to the U.S. Food and Drug Administration began a meeting to discuss Johnson & Johnson’s one-dose COVID-19 vaccine on Friday, setting the stage for a possible emergency use authorization as early as this week.

Bahrain approved Johnson & Johnson’s one-dose Covid-19 vaccine for emergency use, the first country to do so, the National Health Regulatory Authority (NHRA) said on Feb. 25.

The United States expects to roll out 3 to 4 million doses of Johnson & Johnson’s Covid-19 vaccine during the first week of March, pending authorization from the Food and Drug Administration, White House Covid-19 response coordinator Jeff Zients said on Feb. 24.

Johnson & Johnson’s one-dose Covid-19 vaccine appeared safe and effective in trials, the U.S. Food and Drug Administration said, paving the way for approval for emergency use as soon as Feb. 26.

Covid-19 vaccine makers told Congress on Feb. 23 that U.S. supplies should surge in the coming weeks due to manufacturing expansions and new vaccine authorizations.

Johnson & Johnson expects to be able to ship nearly 4 million doses of the company’s Covid-19 vaccine upon authorization in the U.S., an executive said at a hearing in the U.S. House of Representatives on Feb. 23.

French healthcare company Sanofi will provide Covid-19 vaccine manufacturing support to U.S. peer Johnson & Johnson.

Johnson & Johnson submitted data to the World Health Organization (WHO) for emergency use listing of the company’s Covid-19 vaccine, which would allow for wider access of the one-dose shot.

Johnson & Johnson Chief Executive Officer Alex Gorsky told CNBC that people may need to get vaccinated against Covid-19 annually over the next several years, like seasonal flu shots.

South Africa delayed the distribution of the AstraZeneca-University of Oxford Covid-19 vaccine after data suggested it “provides minimal protection” against mild disease from the South African variant.