| vaccine be | 27.65 | An AIDS vaccine never was a given. | ||
| vaccine work | 3.03 | Can a vaccine work? | ||
| vaccine cause | 2.63 | Dead virus vaccine causes fewer cases of polio. | ||
| vaccine protect | 2.24 | The vaccine protects for three to five years. | ||
| vaccine have | 1.97 | The vaccine has mild side effects similar to flu. | ||
| vaccine exist | 1.78 | Vaccine exists. | ||
| vaccine prevent | 1.45 | The vaccine also prevents meningitis C. | ||
| vaccine use | 1.45 | The AIDSVAX vaccine does not use HIV itself. | ||
| vaccine make | 1.12 | He was negative, but the vaccine would make him test positive. | ||
| vaccine contain | 0.86 | The vaccine does not contain any blood products. | ||
| vaccine prove | 0.86 | The new vaccine could prove just as important, the FDA said. | ||
| vaccine become | 0.79 | Most vaccines become effective after two to four weeks. | ||
| vaccine appear | 0.72 | Tested in rats, the vaccine so far appears reversible. | ||
| vaccine help | 0.66 | So the vaccine may help fend off symptoms. | ||
| vaccine come | 0.59 | The vaccine comes in two parts. | ||
| vaccine do | 0.59 | But those vaccines did nothing to stop free-floating virus. | ||
| vaccine require | 0.59 | For adults, the vaccine requires two injections. | ||
| vaccine go | 0.46 | There was no way all the vaccine was going to be delivered on time. | ||
| vaccine need | 0.46 | Vaccines need to be cheap. | ||
| vaccine offer | 0.46 | DNA vaccines offer many practical advantages. |