Pfizer BiValent Info

Pfizer Bivalent Vaccine Information 

The Pfizer (BIVALENT) BA.1 COVID-19 vaccine for use in individuals aged 18 years and older. The Vaccine uses similar technology to the Pfizer (COMIRNATY) and Moderna (SPIKEVAX) vaccines to induce immunity..

While NOT recommended for the primary course of vaccination, the Pfizer BiValent Vaccine is recommended as a booster Vaccine to those who have not had either a booster or Covid infection in the last 6 months. Pfizer BA1 is NOT recommended as a booster in anyone under 18 years, however the Pfizer PB4-5 is registered for people 12 years and older.

How effective is the Pfizer BA.1 Vaccine?

In people without prior infection, the Pfizer (BIVALENT) BA.1 vaccine provided 1.6 times (95% CI: 1.17, 2.08) higher neutralising antibodies compared to the Pfizer/BioNTech (COMIRNATY) original vaccine against the Omicron BA.1 variant. Neutralising antibody titres were similar for the Pfizer (BIVALENT) BA.1 and Pfizer/BioNTech (COMIRNATY) original vaccine against the original virus (geometric mean ratio 0.99 [95% CI: 0.82, 1.20]).  

What is the current advice about when to have Boosters?

The ATAGI 2023 booster advice  replaces previous ATAGI COVID-19 vaccine booster advice (ATAGI, 2023a). 

Booster doses of COVID-19 vaccine should be given at least 6 months after the most recent COVID-19 vaccine dose or previous SARS-CoV-2 infection (whichever is the most recent) (ATAGI, 2023a). 

Can I have the Pfizer vaccine if I have previously had Moderna?

Co-administration of the Pfizer bivalent booster vaccines with other non-COVID vaccines is acceptable, as per current ATAGI 2023 booster  advice (ATAGI, 2023a). 


What if I have previously had Covid?

Past infection with SARS-CoV-2 is not a contraindication to vaccination. ATAGI recommends  that vaccination should be deferred for 6 months following a confirmed SARS-CoV-2 infection, as this, together with prior vaccine doses received, will boost protection against COVID-19 (ATAGI, 2023a).  


Side Effects

The most commonly reported local adverse reactions following a second booster dose of the Pfizer (BIVALENT) BA.1 vaccine were: 

There are reports of a very rare side effect involving blood clotting with low blood platelet count after receiving the AstraZeneca (VAXZEVRIA) vaccine. The AstraZeneca vaccine (VAXZEVRIA) is made in a different way. There is no evidence of this condition being linked to the Pfizer (COMIRNATY) COVID-19 vaccine. 



More information can be found by clicking on the link for a Consumer Medication (CMI) Summary 

This pharmacy uses the ATAGI Clinical Guidance for COVID-19 Vaccine Providers