Where to start? The tip of the iceberg :

1) Healthy adults aged 18–59 years only, mean age of the cohort was 39.7 years 2) Long list of exclusions 3) 1 Booster dose only, 1 year after the primary 4) Samples after booster up to only 21 days maximum 5) IgG4 did rise too relatively after booster 6) At 12 months, the seropositivity rate decreased to 25.9%. 7)- here it comes! - we were only able to investigate the RBD-specific IgG subclasses for the wild-type strain. Therefore, we cannot confidently draw the practical conclusions regarding the Beta, Gamma, Delta and Omicron variants 8) 2-dose primary immunization of COVID-19 inactivated vaccine only achieved low neutralization ability

When are people going to understand 1) how to critically read studies 2) that vaccines ultimately rely on natural immunity and cannot hope to achieve anything better 3) are thus futile (or even damaging) when given in an intramuscular way to non-elderly and people with reasonable natural immunity against a fast-evolving respiratory RNA virus