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¦.
Typhoid vaccines. Typhoid vaccine can prevent typhoid. There are two vaccines to prevent typhoid. One is an inactivated (killed) vaccine gotten as a shot. The other is a live, attenuated (weakened) vaccine which is taken orally (by mouth). Top of Page. Who should get typhoid vaccine and when? Routine typhoid vaccination is not recommended in the United States, but typhoid vaccine is recommended for: Travelers to parts of the world where typhoid is common. (NOTE: typhoid vaccine is not 100% effective and is not a substitute for being careful about what you eat or drink). People in close contact with a typhoid carrier.