Above is the the graph that was used recently in the IMAC webinar to discuss the safety and efficacy of the new grey top Pfizer bivalent booster vaccine. The new bivalent booster vaccine supposedly protects against the original Wuhan strain and the BA.4/5 strains.
The graph below is from RNZ visualisations as at 7 March 2023 showing variant prevalence.
Note that the original strain doesn’t feature and the BA.4 and BA.5 variants have dwindled to effectively zero.
Why would NZ be introducing a booster in March and April 2023 for strains that have been responsible for minimal infections since Jan 2023? What ‘science’ is the government following?