In western Kenya, Charles Nyaguda has just received his first COVID-19 vaccine dose.
He's 72 and living with blindness, and he says he's worried that he's not going to get his second dose.
His AstraZeneca shot was made by the Serum Institute of India and supplied through the global sharing scheme COVAX.
But India is now engulfed in its own coronavirus crisis, and is diverting shots made at the Serum Institute for domestic use.
Sources have told Reuters that India's vaccine exports, halted in March, are unlikely to resume until at least October.
That's left tens of millions of Africans, who have received their first dose, in limbo on a continent where most of the 1.3 billion population have had no access to coronavirus vaccines at all.
While Africa has so far avoided outbreaks on the scale of the United States, parts of Europe and now India, senior COVID advisor at the Tony Blair Institute, O.B. Sisay, says as long as vaccination rates remain low, the continent is vulnerable.
"So, it seems as though we have a perfect storm if we do not have further vaccines coming into the continent and increase the rate at which we are vaccinating people, we could see a more virulent strain taking hold of the continent even as we are reducing the rate of vaccination."
Africa's dilemma highlights the inequality between rich and poor nations.
Wealthier countries were able to corner vaccine supplies early on and many are now easing restrictions.
Poorer countries have depended on COVAX.
Between February and May, Africa received just 18.2 million of the 66 million doses expected through COVAX.
Eight African countries have used all the doses they received via COVAX - effectively halting their vaccination drives. Others are running low.
With 80% of all COVAX doses administered in Africa first shots of AstraZeneca - the continent now faces a shortfall.
The WHO says 20 million doses are need to deliver second doses by the end of June, and another five million for July.