Not only do COVID-19 vaccines do a ‘good-enough’ job, it’s also important to establish that no two vaccines or pathogens are the same, and the immune defenses they do generate cannot be properly compared. For one, the threshold of protection, or the immunity needed to keep a person from getting sick greatly differs from every pathogen, and the severity of infection it could cause. For this reason, it could be considered possible for COVID-19 vaccines to mount a comparatively lesser-lasting, or waning response.
It might also signify that we need to wait for more time to get the ‘ideal’ results we want from our COVID-19 vaccines. Further, it should also be noted that the magnitude of antibodies, immune responses seen with other vaccines differ on counts. If the measles shot mounts lifelong antibodies, the tetanus vaccine can have decaying antibodies, which, however, are offset by the large number of antibodies created in the first place. These vaccines have also gone through years, and years of progress and research to help track antibody decline, and provide updations when needed, which is not possible right now with COVID-19.