| PFU | plaque-forming unit; pock-forming unit |
|---|---|
| PI | first meiotic prophase; isoelectric point; pacing impulse; package insert; pancreatic insufficiency;... |
| PN | papillary necrosis; parenteral nutrition; penicillin; perceived noise; percussion note; periarteriti... |
| PrA-HPA | protein A hemolytic plaque assay |
| PRNT | plaque reduction neutralization test |