toggle menuMENU What's the difference between the third dose and the booster? Question:What's the difference between the third dose and the booster?Answer: The Joint Committee of Vaccination and Immunisation recommended a ‘third primary dose’ for people who have the following conditions: blood cancers, stem cell transplants, advanced HIV/AIDS, people with recent organ transplants and people who have had to take medicine to suppress their immune system for an auto-immune condition This third dose is specifically for people whose immune systems were severely weakened by a certain set of health conditions when they had their first two doses - meaning their first two doses may not have given them complete protection at the time Your GP or specialist doctor will let you know whether you need a third dose – this will usually be at least three months after your second dose. However, recent JCVI advice stated that those who have not yet received their third dose may be given the third dose now to avoid further delay