Researchers at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia, have released a model that suggests vaccinating people aged between 18 and 39 will help reduce transmission, protecting all people throughout the community.

Jodie McVernon, Professor and Director of Doherty Epidemiology, developed the model on the outcomes based on the Delta variant’s higher rate of transmissibility. She said older people bore the brunt of COVID-19 but younger people were responsible for transmitting the virus more.

She said, “In this case, it’s really the 20-29 years that are peak spreaders. What we’re proposing now is a shift in the strategy in order to maximize the benefits of this [vaccination] program across all individuals in the population.”

Prof. Catherine Bennett, Deakin University’s Chair in Epidemiology, who supported the model said public health officials needed to adjust the distribution plan to respond to the highly contagious Delta variant.

Some states and territories in Australia have already been vaccinating young people for months. Everyone over 18 in Greater Sydney has been urged to strongly consider getting vaccinated with any available vaccine.

However, the problem is some young people have been turned away.

Australian Medical Association vice-president Dr. Chris Moy said he could understand why the system was breaking down in parts of Sydney amid high COVID case numbers, according to ABC News, Australia.

Dr. Moy said there were problems with vaccine access in parts of Sydney because many medical centers and pharmacies had been forced to put staff into isolation due to a surge in new cases.

He said, “It’s not easy to provide a vaccine in a COVID-safe environment at the moment with practices and staff getting knocked out because of cases.”

Dr. Moy also pointed to reports of those still not technically eligible, finding a way to access Pfizer vaccines, explaining, “Sometimes, people are pushing their way in.”

NSW Premier Gladys Berejiklian expressed concerns over reports of people facing trouble booking for a vaccine. She said, “If we can streamline those opportunities, we will.”

Dr. Moy said the current phases were important to protect the vulnerable. He said he is worried about any amendment to the existing framework, including the prioritization of younger people, could create even more confusion, per ABC News, Australia. He said, “What we’re trying to do is stop a complete free-for-all.”