The third primary dose is for immunocompromised for ages 5-11 years:

The COVID-19 Vaccine Technical Advisory Group has recommended that severely immunocompromised individuals aged 5-11 years receive a third primary dose of the Pfizer COVID-19 vaccine.

The third primary dose is optional but recommended.  

Clinicians caring for severely immunocompromised children, who have turned 12 between dose 2 and dose 3, are recommended to consider the adult vaccine for the third primary dose, after taking into account their age, clinical circumstances, and experience following previous doses.

The third primary dose is for immunocompromised for ages 12 and above:

The COVID-19 Vaccine Technical Advisory Group has recommended that severely immunocompromised individuals aged 12 and older receive a third primary dose of the Pfizer COVID-19 vaccine.

The third primary dose is optional but recommended.  

There are specific criteria for who can qualify for a third primary dose, this includes individuals who were undergoing immunosuppressive therapies prior to or at the time of their first or second dose.

Third primary doses and booster vaccines are different:

An additional, third primary dose is for people who may not have generated an effective protective response to the standard two doses of COVID-19 vaccine due to being severely immunocompromised. These people can now get a third dose as part of their routine vaccination series. 

Third primary dose schedule:

The third primary dose is recommended at least 8 weeks after the second dose.

However, the timing also needs to consider current or planned immunosuppressive therapies. If the period of least immunosuppression is less than 8 weeks, vaccination can be given any time from four weeks after the second dose. 

Where possible, it is recommended to delay the third dose until two weeks after the period of immunosuppression (in addition to the clearance time period of therapeutic).

Booster doses for immunocompromised:

A booster dose for immunocompromised can be given anytime from 3 months (ideally 6 months) after they have had their third primary dose.

More detail is available here.

Call 0800 IMMUNE (466 863) for clinical advice

Last updated: 05 May 2022