Mr Ghebreyesus said it was not right that the youth, healthier adults in rich countries were being vaccinated, even before the health staff and old people in poorer countries could receive the vaccine.
Director-General Tedros Adhanom Ghebreyesus has questioned the fairness in distribution of the vaccines.
He said that over 39 million vaccine doses had been given in 49 richer states - but one particular nation had only 25 doses.
This compared with just 25 doses in one low-income country. The programme encourages rich countries to invest in Covax, which provides them with proportional access to Covax vaccines if others they have invested in fail.
He said 44 such deals were struck in 2020 and at least 12 have already been signed this year.
"I need to be blunt", he said, speaking at the WHO's executive board meeting. The WHO chief explained that inadequate information sharing by drug makers has impeded the agency's ability to greenlight more shots for emergency use, and called on vaccine producers to accelerate the approval process by providing "full data for regulatory review in real time".
Ensuring all countries will have access to any COVID-19 vaccines is the promise of a global mechanism established last April, known as the COVAX Facility.
He urged countries and manufacturers to share doses more fairly around the world.
The WHO chief said that these actions will not help in stopping the spread of coronavirus but "will only prolong the pandemic".
Meanwhile, an independent panel investigating the global response to the pandemic said that World Health Organization and China should have acted faster in the initial stages of the coronavirus outbreak, BBC reported.
In December 2021, the People's Vaccine Alliance in a report warned that more than 90% of the population in poor countries will miss out on getting coronavirus jabs.
Tedros said plans to start vaccine deliveries in February to numerous world's poorer countries were now at risk.
"It's right that all governments want to prioritise vaccinating their own health workers and older people first", he said.
The facility is created to bolster procurement of promising COVID-19 vaccines to ensure the "best possible prices, volumes and timing for all countries".