Nurith Aizenman

Africa just marked its worst pandemic week ever and its third wave of COVID-19 — largely driven by the delta variant. Vaccine shipments to the continent are moving slowly.

Vaccines may not be as effective for those who are immuno-compromised. Protecting them needs to be made a top priority, says researchers — to keep them safe and to slow the emergence of variants.

Thanks to widespread vaccinations, the U.S. is reopening. Meanwhile, countries without similar access to doses are angry and fearful — amid signs the COVID-19 catastrophe in India could spread.

India's freeze on AstraZeneca exports is upending Africa's already limited vaccination progress, as the Africans who got their first dose are coming due for their second with no supply in sight.

While many African countries need more COVID-19 vaccines, others are struggling to administer the shots they have. Malawi and South Sudan have even had to throw out unused and expired doses.

One of the hottest areas of research right now: studies to determine how well current vaccines work against emerging coronavirus "variants of concern."

It's one of the hottest areas of COVID-19 research: How well do the various vaccines work against the variants? New findings are coming out daily. Here's what's known so far, and what's pending.

For this health expert based in Boston, the effort to get vaccines to his native South Africa was intensely personal.

South Africa is a case study of the inequities around the coronavirus vaccine. It has one of the world's worst outbreaks, fueled by a new variant. Yet officials are struggling to buy enough vaccines.

New results from a COVID-19 vaccine trial in South Africa suggest the vaccine that was developed by AstraZeneca may not be as effective against the variant found there.