This story originally appeared on ValueWalk Pascal Soriot, CEO of AstraZeneca plc, said the company still doesn’t know if a third dose of its COVID-19 vaccine will be necessary to maintain protection against the virus. Time Will Tell Soriot told CNBC: “There are two dimensions to this immunity—antibodies [which] decline over time, but the second, very important dimension of vaccination is the so-called T-cells. They tend to protect people against severe disease, but they also provide durability.” “With the technology we use, we have very high production of T-cells. We’re hoping we can have a durable vaccine that protects for a long period of time. So whether we will need a third booster or not, is not clear yet, only time will tell.” Soriot said the company needs to track the vaccine’s effectiveness over time to see if a third shot would be necessary. “We know that [our vaccine] has …