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¦.
A typhoid vaccine can prevent about 50% to 70% of cases. The vaccine may be effective for up to seven years. It is recommended for those at high risk or people traveling to areas where the disease is common. typhoid vaccine can prevent about 50% to 70% of cases. The vaccine may be effective for up to seven years. It is recommended for those at high risk or people traveling to areas where the disease is common.