(Reuters) - The World Health Organization said on Wednesday it continues to monitor safety evidence reviews of AstraZeneca’s COVID-19 vaccine but that the shot’s benefit-risk profile “weighs heavily in favour of its use” amid reports of rare brain blood clots. Alejandro Cravioto, chair of the WHO’s Strategic Advisory Group of Experts (SAGE) on Immunization, told a briefing the panel was “comfortable” with the vaccine’s use, since many of the countries using it have safety warning signal systems in place and are not reporting problems. Many European countries briefly stopped using AstraZeneca’s COVID-19 vaccine earlier this month while their drug safety authorities investigated rare cases of blood clots.