JOHANNESBURG (AP) — South Africa is considering giving a COVID-19 vaccine that is still in the testing phase to health workers, after suspending the rollout of another shot that preliminary data indicated is not effective at preventing mild to moderate illness from the variant dominant in the country. The country was scrambling Monday to come up with a new vaccination strategy after it halted use of the AstraZeneca vaccine. Among the possibilities being considered: mixing the AstraZeneca vaccine with another one and giving Johnson & Johnson’s single-dose vaccine, which has not yet been authorized for use anywhere, to 100,000 health care workers while monitoring its efficacy against the variant.