[convnet]

A main difference in this research is that it's very difficult to actually measure the levels of neutralizing antibodies. Traditional antibody tests aren't able to tell if you have high neutralizing antibody levels yet, as a BSL3 lab is needed to perform these experiments with live virus. Antibody levels aren't always a clear indication of level of immunity, so this was still an open question with COVID.

This study has serious implications for a recommendation for a third dose. It was known for a while that a 3rd dose increases levels of neutralizing antibodies, but this study now ties that increase to a significant boost in immunity which has implications for the new variants like Delta. It means that likely we don't need to wait 3-6 months for approval for a new strain specific booster. We can just use the doses we already have to bump up the neutralizing antibody level.

It also has implications for how long the 2-dose or 1-dose regimens are good for, since it has been known that the neutralizing antibody level does tend to dip after around 6-9 months, so this gives more evidence for the benefit of getting a booster after around 6 months to keep neutralizing antibody levels high.