World Health Organization backs a second, cheaper malaria vaccine

Catch up quick: Malaria sickens about 250 million people every year, killing over 600,000 — most of them children under 5.

• In areas with highly seasonal malaria transmission, WHO said R21 was shown to reduce symptomatic cases of the mosquito-borne illness by 75% during the year following a three-dose series. A fourth dose given a year later maintained high efficacy.
• WHO said the two vaccine options showed similar efficacy, and there's no evidence on whether one performs better than the other.
• A study published almost a year ago found RTS,S had 30% efficacy in severe cases.

What we're watching: R21, which was developed by the University of Oxford, is expected to become available in mid-2024 and cost between $2-$4 per dose — about half of what RTS,S costs.

• The Serum Institute of India, the world's largest vaccine maker, is lined up to manufacture more than 100 million doses per year, according to The Guardian. By comparison, there are just 18 million doses of RTS,S.
• At least 28 African countries plan to include a malaria vaccine in their national immunization programs, WHO said.