LONDON, ONT. -- A massive cohort of newly vaccine-eligible young adults will face long delays after the region’s health unit could not secure additional doses.

All adults (18 and older) can register with the Middlesex-London Health Unit (MLHU) for COVID-19 vaccination starting May 18, but according to projected vaccine shipments from the province, barely one in six young adults will secure a shot in the next four weeks.

“We have capacity in the next four weeks for vaccine booking of about 24,000 people, unfortunately in that age group there are about 135,000 people in this area,” explained Medical Officer of Health Dr. Chris Mackie during a media briefing.

Dr. Mackie adding that the massive increase in eligibility needs to be matched by greater vaccine availability.

“I’m not particularly concerned about whether the vaccine goes to pharmacies, primary care, mass (vaccination) clinics, or somewhere else to vaccinate. The concern that I have is that we need more vaccine,” Mackie said.

Finishing touches are underway for next week’s opening of Middlesex-London’s fourth mass vaccination clinic at the Earl Nichols Recreatiom Centre— increasing the region’s capacity to administer shots.

Unless more shots are secured, however, a fifth location will not be required during the next four weeks.

On Monday evening, Dr. Mackie tweeting that his “last-ditch effort this afternoon (has) failed to procure additional supplies for tomorrow’s opening to adults 18-39.”

“I’m sorry in advance for the frustrating situation of limited vaccine supply,” adding Mackie in a second tweet.

All adults (18 and over) can register online starting between 7:30 a.m. and 8 a.m. on May 18 at covidvaccinelm.ca.

Young adults that CTV News spoke with were not discouraged by the delay.

“Given the circumstances and the shortages, it is what it is,” said Joel Thompson. “We just have to keep moving forward, stay isolated, do what we have to do.”

The eligible population in Middlesex-London is expected to grow once again during the week of May 31, with the addition of 12-17 year olds.