**Table 2.**

*Tested efficacy of vaccines against VOCs.*

against other lineages was increased after booster dosages [89]. Overall, the emergence of VOCs over time decreases the neutralisation efficacy of vaccines, despite booster immunisation. The first VOC alpha had little effect on antibody neutralisation activity in post-vaccination sera (**Table 2**). Neutralisation was reduced even further by new emerging variants and waning with time [90–99], and the newly evolved omicron BA.5 variant has better survival fitness, transmissibility, and neutralisation even after booster immunisation.
