Triple the amount of surface water is far from enough to suggest a global flood is remotely possible, let alone plausible.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10505422/#ref19

They have shown high efficacy against these endpoints in experimental and observational studies (1–13). Evidence suggests that these vaccines also prevent infection (5, 14–18) and potentially reduce transmission (19–23), albeit with smaller effects against the highly transmissible Omicron variant compared with wildtype severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and earlier variants (24–26).

The exception is Omicron, and evidently isn't a complete exception anyway.

In addition, as this was a conversation originally about vaccine mandates, one of the first mandates in the US was put into effect ~2 months before Omicron was reported in Nov. 2021. So even if no vaccine or booster did anything to stop transmission of Omicron, the mandates were fully justified given the vaccines definitely did reduce transmission and severity of variants prior to that.

In this study, vaccinated Omicron index case-patients seemed to have the same transmission capacity as nonvaccinated persons. We did not find this increased transmission capacity for the Delta variant, where significant differences in SAR were observed in global, household, and occupational settings (Table 1) within groups.

How one variant interacts with vaccination does not describe how every variant does; your own study is, at best, documenting an exeception to the rule that vaccines work.