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¦.
There are two types of typhoid vaccine, one is injected and the other is given by mouth (orally). Neither vaccine provides protection for longer than 3 years, so if you will be travelling to a country where typhoid is present, and it has been about 3 years since your last vaccination, you may need to be revaccinated.here are two types of typhoid vaccine, one is injected and the other is given by mouth (orally). Neither vaccine provides protection for longer than 3 years, so if you will be travelling to a country where typhoid is present, and it has been about 3 years since your last vaccination, you may need to be revaccinated.