请仔细看报道，不要断章取义！！ 打了2针（针对印度变异株）的效果就不好， 打了一针的就更差了。

The team compared the concentrations of the neutralizing antibodies among the variants. They found that people who had been fully vaccinated with two Pfizer doses had antibodies that were 6 times lower against the B.1.617.2 variant, 5 times lower against the B.1.351 variant, and 2.6 times lower against the B.1.1.7 variant when compared to the original strain.

The antibody response was even lower in people who had received only one dose. After a single Pfizer dose, 79% of people had neutralizing antibodies against the original strain, which fell to 50% for the B.1.1.7 variant, 32% for the B.1.617.2 variant, and 25% for the B.1.351 variant.