The other type is virulent (produces disease), is the cause of FIP, and is called feline infectious peritonitis virus (FIPV). It is believed that FIP occurs when FECV mutates to FIPV in the cat and starts to replicate in the cat's cells. What causes this mutation is unknown.he other type is virulent (produces disease), is the cause of FIP, and is called feline infectious peritonitis virus (FIPV). It is believed that FIP occurs when FECV mutates to FIPV in the cat and starts to replicate in the cat's cells. What causes this mutation is unknown.
How long does a typhoid shot last?   According to the CDC website, a booster dose is needed every 2 years for people who remain at risk.. The oral (live) vaccine lasts 5 years before another dose is neededâ¦.
It takes one week for the vaccine to be effective. You can still protect yourself against Typhoid even without the vaccination. Take precautions with food and drinks while in an effected area: (From the Centers for Disease Control and Prevention) Boil it, cook it, peel it, or forget it.t takes one week for the vaccine to be effective. You can still protect yourself against Typhoid even without the vaccination. Take precautions with food and drinks while in an effected area: (From the Centers for Disease Control and Prevention) Boil it, cook it, peel it, or forget it.