<s>[INST] Yes, I was given the Twinrix vaccine in does of three injections over a time period. I recall that the nurse who administered my injections forgot to shake it until it turned opaque as directed. Will that have any ill effect or be harmful to me since it is recommended that Twinrix be shaken until turns opaque before injection? Thanks, Concerned Lady [/INST] Hello, I understand your concern. I am Chat Doctor, infectious diseases specialist, answering your query. In my opinion you should not worry. It never causes harm. Not Shaking the bottle never harms you. Vaccine is for the protection purpose. So if someone won't shake it, its effect are lowered, but it never harms you. You can check the title of the antibodies circulating in the blood of you to check the effectiveness of the vaccine administered. And accordingly if the further action is required can be taken. I will be happy to answer your further concern, you can ask me on bit.ly/ Chat Doctor.  Thank you. ChatDoctorInfectious diseases specialist. </s>