If it is 99.6% is is considered as 100%. At least by all international organizations.No vaccine can offer 100% protection.
What is the mortality rate for fully vaccinated Indonesian?
What is the % of those fully vaccinated persons to be admitted to hospital?
What is the mortality rate for non vaccinated Indonesian?
2.2m infected and just under 59,000 dead = 2.7%. Assuming they were all non vaccinated.
If the vaccine can further reduce the number of death as well as serious enough to be admitted to hospital then it is doing a decent job.
Better than nothing.