Complex sentence: When used in ring-vaccination, rVSV-EBOV has shown a high level of protection; around half the people given the vaccine have mild to moderate adverse effects that include headache, fatigue and muscle pain.
Split into simpler sentences: When used in ring-vaccination, rVSV-EBOV has shown a high level of protection. Around half the people given the vaccine have mild to moderate adverse effects that include headache, fatigue, and muscle pain.