Faith leaders from around the world are calling for an end to "vaccine nationalism" and the hoarding of vaccines by wealthier countries.
In an open letter, they remind wealthy countries of their "moral obligation" to ensure that the vaccine can "reach everyone, in every country".
"The Covid crisis has reminded us all of our interdependence, and of our responsibilities to care for one another. We can each only be safe when all of us are safe," the letter says.
"If one part of the world is left to suffer the pandemic, all parts of the world will be put at ever-increasing risk."
The letter has been signed by dozens of faith leaders, including Cardinal Peter Turkson, former Archbishop of Canterbury Dr Rowan Williams, and the Anglican Archbishop of Cape Town Dr Thabo Makgoba,
They ask for the production of Covid vaccines to be "massively" scaled up so that enough can be produced for the entire global population.
The call comes at a time when many countries are struggling with high Covid numbers, like India, which is in the grip of a devastating second wave that has overwhelmed hospitals and crematoriums.
Yet many low and middle income countries have only small quantities of vaccine, in stark contrast to well-stocked countries in the global north that have already administered millions of doses as part of their national vaccine drives.
"The access of people to life-saving Covid-19 vaccines cannot be dependent on people's wealth, status, or nationality," the faith leaders say.
"We cannot abdicate our responsibilities to our sisters and brothers by imagining that the market can be left to resolve the crisis or pretend to ourselves that we have no obligation to others in our shared humanity."
They add: "This unprecedented public health crisis calls, above all, for global solidarity, for all people to stand together as brothers and sisters.
"The same spirit of unity and common purpose that has driven scientists to develop Covid-19 vaccines at breathtaking speed, that drives the care of those tending to the sick, must also inspire the leaders of government, civil society and the private sector to massively ramp up vaccine production so there are sufficient doses for every person in the world to be vaccinated."
The letter has been issued as part of wider action by the People's Vaccine Alliance, a coalition of organisations and activists campaigning for a 'people's vaccine' for Covid-19, which would be based on shared knowledge and freely available to everyone, everywhere.
Fionna Smyth, head of global advocacy and policy at Christian Aid, one of the charities supporting the People's Vaccine Alliance, said a transformation was needed in the way that vaccines are produced and distributed, with pharmaceutical companies sharing their knowledge patent-free.
"We know that our best chance of all staying safe is to ensure Covid-19 vaccines are available for all as a global common good as soon as possible," she said.
She criticised pharmaceutical companies for "protecting their monopolies and putting up barriers to restrict production and drive up prices, leaving us all in danger".
"No one company can produce enough for the whole world. So long as vaccine solutions are kept under lock and key, there won't be enough to go around. We need a People's Vaccine, not a profit vaccine," she said.
"The failure to provide vaccine equity to some of the poorest and most marginalised communities around the world is a moral issue, which the world must face up to."