Efficacy is short-lived. The turnaround for Thailand getting supply and people fully vaccinated is going to be like 3 years. By the time everyone is vaccinated the majority of people will be unprotected....d/t waning immunity. The solution: let this virus run rampant. Some 80 year old expats are going to die. Who cares- they were going to die very soon anyways from obesity and the pub.
I understand that about vaxxes. Specific to the flu virus, the reason for annual flu shots is that particular virus is constantly mutating, so even if last year's jab confers lifetime immunity, it will only be against that strain.
But regarding having been infected and the "immunity" it confers, from what I have read on the subject, the anti-body count deteriorates rapidly. This has led to numerous cases of the fully vaxxed post-infection, still succumbing to a second attack.
Fortunately, there are some vaxxes which do confer life-time immunity such as Small Pox and Polio, but there is yet to be one that can do so with any of the Coronaviruses.