Commentary: Omicron-specific vaccines may give slightly better COVID-19 protection

This type of analysis shows the original vaccine is quite good at restoring protection against disease caused by different variants when given as a booster.

Variant-modified vaccines such as the newly approved Omicron booster are predicted to improve that by 5 to 10 per cent, depending on the variant and level of existing immunity. This might seem like a small improvement but it could mean additional lives saved.

That said, you are at much greater risk of disease if it has been several months since your last booster. That’s why it’s best to get boosted as soon as you’re eligible, rather than wait for an Omicron-specific booster.


In Australia, the government has accepted the Australian Technical Advisory Group on Immunisation (ATAGI) advice to wait until current Moderna booster stocks run out before putting the bivalent Omicron boosters into circulation.

This seems like the right call, given the Omicron boosters probably offer only a modest improvement in protection against the Omcicron sub-variants currently circulating.

In the future we might see annual COVID-19 boosters adapted to the currently circulating strains or predicted strains, like season flu shots. There appears to be a desire to do this in the United States with the Federal Drug Administration fast-tracking authorisation of booster mRNA vaccines that target the Omicron BA.4/BA.5 subvariants, before data is available on how well they work.

Rather than constantly updating COVID-19 vaccines, an alternative approach is to develop a “variant-proof” vaccine that targets multiple SARS-CoV-2 variants. We could combine this with treatments like nose sprays that stimulate immunity against a range of viruses.

For now, bivalent vaccines work as well, if not a little better, than the original vaccines so transitioning to them makes sense.

Nathan Bartlett is Associate Professor, School of Biomedical Sciences and Pharmacy at the University of Newcastle. This commentary first appeared on The Conversation.