I wonder if this is what the Pur company went through quietly. Their pre 2020 old dark blue filter boxes claimed it could filter out microorganisms (microbial cysts, giardia lamblia, cryptosporidium). They had a shortage of filters for awhile which probably was due to something like this and then came back with aqua boxes that no longer mention their filters can filter microorganisms. I kept the old dark blue box when I noticed they had a new color. I was trying to see what was different and that was the only thing.