GENEVA/ZURICH (REUTERS) - It is a travesty that some countries still have not had enough access to vaccines to begin inoculating health workers and the most vulnerable people against Covid-19, the head of the World Health Organisation (WHO) said on Tuesday (April 6).

"Scaling up production and equitable distribution remains the major barrier to ending the acute stage of the Covid-19 pandemic," WHO director-general Tedros Adhanom Ghebreyesus told a news conference.

"It's a travesty that in some countries health workers and those at-risk groups remain completely unvaccinated."

The Covax scheme, led by the WHO and GAVI vaccine alliance, has delivered 36 million doses to 86 countries and economies over the past six weeks, Tedros said.

The president of Namibia, Hage Geingob, one of several leaders invited to speak ahead of World Health Day on Wednesday, decried what he called "vaccine apartheid" under which some countries were forced to wait while others obtained doses.

Geingob said Namibia had received Covid-19 vaccines from "our good friends" India and China, but was still waiting for other vaccines despite having paid a deposit for them.

Tedros said Namibia would receive some vaccines from the Covax programme in around two weeks.

Barbados Prime Minister Mia Amor Mottley said her Caribbean island nation had received its first tranche of vaccines via Covax on Tuesday, enough to cover 3 per cent of its population.

"But for many globally, this has been a difficult exercise. Because as we've seen the spikes (in disease) can literally grow, (and) we've not had access even when we are prepared to pay," she said.

Azerbaijan President Ilham Aliyev said the issue of equal and fair vaccine distribution was of paramount importance, adding: "Some countries hold several times more vaccines compared to their actual needs. It is clear that in such circumstances, other countries will face a vaccine shortage."