Vaccine hesitant people may have anxiety over safety concerns, or they might belong to a community that historically has mistrusted the medical establishment, according to the study.
Investigators said the vaccine was effective across all ages, including older people — which previous studies in other countries had failed to establish.
In a statement on Friday, the WHO said that based on available data the review team found no increased risk of blood clotting conditions in people who received the AstraZeneca-Oxford vaccine.