Transmission af skoldkoppevirus fra recipienter af levende skoldkoppevaccine (Oka/ Merck) uden skoldkoppelignende udslæt er rapporteret, men ikke bekræftet.
Transmission of varicella vaccine virus from recipients of Varicella Vaccine live (Oka/ Merck) without a varicella-like rash has been reported but has not been confirmed.