Dr Jeffrey Lazarus was speaking to Euronews after a third vaccine claimed to have had success at fighting COVID-19 in trials.
With at least three coronavirus vaccines now in the pipeline, the world needs to focus on how they will be distributed, an expert has told Euronews.
On Monday a vaccine developing by Oxford University and pharmaceutical firm AstraZeneca was revealed to be up to 90% effective.
That follows hot on the heels of Pfizer-BioNTech and Moderna that are claimed to be up to 95% effective.
"So the world really needs to focus now on the logistics," Dr Jeffrey Lazarus, a global health expert at the Barcelona Institute for Global Health, told Euronews.
"Not just getting it [the vaccine] to the major cities but how do we get it to rural areas in tougher to reach population?
"It's going to be quite a logistical challenge. Refrigeration is an issue and for the vaccines that require very very cold temperatures, many countries in the world won't be able to receive many doses at any one time."
All the vaccines have been developed in record time and it's feared this could play into the hands of the anti-vax movement.
But Dr Lazarus said these concerns are unfounded.
"I don't think there has ever been so much focus on safety of vaccine development with the whole world watching," he said.
"We have independent regulatory bodies in every country and across Europe scrutinising data when approvals are made and vaccines are released to the general public."
Watch the full interview with Dr Lazarus in the video player, above.