“vaccines cannot keep up with rapidly changing variants”In multivariable analysis,the bivalent vaccinated state was independently associated with lower risk of COVID-19 (HR, .70; 95%C.I., .61-.80), leading to an estimated vaccine effectiveness (VE) of 30% (95% CI, 20-39%). Compared to last exposure to SARS-CoV-2 within 90 days, last exposure 6-9 months previously was associated with twice the risk of COVID-19, and last exposure 9-12 months previously with 3.5 times the risk.
Your link is misinterpreting the underlined part here.
COMPARED TO EXPOSURE WITHIN 90 DAYS, you have 2x the risk of infection at 6-9 months and 3.5x the risk at 9-12 months.
Which means that, just like flu, the vaccines cannot keep up with rapidly changing variants, and the immune system antibody levels drop. BUT the memory cells remain, which means infection severity is still exceedingly likely to be much lower with boosters.
I mean.....
Opinion | Are Vaccines Fueling New Covid Variants?
The virus appears to be evolving in ways that evade immunity.
www.wsj.com