President Joe Biden announced several changes to the country’s COVID-19 vaccine supply and distribution plans late Tuesday, in an effort to streamline and increase vaccinations in states, tribal areas and territories.

Biden also stated that the U.S. vaccine distribution policy would become more regular and predictable. To-date, governors have bemoaned the irregularity of deliveries of unknown quantities, which made scheduling appointments nearly impossible week-to-week in most states.

“Until now we’ve had to guess how much vaccine to expect for the next week. From this week forward ... we will ensure states tribes and territories will always have a reliable three-week forecast,” Biden said.

The allocation will also increase to about 10 million doses weekly, or about 1.4 million more than currently allocated, Biden said. The more than 15% increase in doses is also a significant increase from the nearly 4 million per week being shipped prior to Biden taking office.

The U.S. Centers for Disease Control and Prevention has now tracked more than 44 million doses shipped, with more than half administered in first and second doses. The numbers represent a significant acceleration in vaccinations, which were lagging doses shipped in the first few weeks of the national rollout.

Biden also announced that the U.S. would be purchase an additional 100 million doses from both Pfizer (PFE)/BioNTech (BNTX) and Moderna (MRNA), pushing the total commitment to 600 million doses — or enough to vaccinate 300 million Americans.

Moderna confirmed the news in a statement Wednesday, noting the company “is in discussion with the U.S. government to purchase an additional 100 million doses of the Moderna COVID-19 vaccine for delivery in the third quarter of 2021.”

But with the slow ramp-up of production, and reported issues with Johnson & Johnson’s (JNJ) vaccine even before it has been authorized, the question of meeting global demand looms large for the two frontrunners.

To that end, Sanofi (SNY) announced late Tuesday it is partnering with Pfizer to help produce 100 million doses of Pfizer and BioNTech’s COVID-19 vaccine.