The production of influenza vaccines traditionally involves hen’s eggs. However, there is a different method for cell-based influenza vaccines — such as Flucelvax Quad, the only cell-based flu vaccine approved for use in Australia. It’s approved for use in people aged 9 years and older but has not been added to the National Immunisation Program (NIP) schedule. Studies show that cell-based vaccines have a similar efficacy and safety profile to standard (egg-based) flu vaccines. Normally, neither type is recommended over the other. However, standard flu vaccines are preferred for use in pregnancy because a large body of evidence supports their safety for pregnant women. The safety of cell-based flu vaccines during pregnancy hasn’t been assessed.