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¦.
The oral vaccine should be completed one week before you travel, as protection takes at least seven days to begin. This oral vaccine should only be given to children over 6 years of age. Antibiotics and some malaria tablets can stop the oral vaccine working.t can even be fatal. You should be immunised against typhoid before you travel to certain countries where the risk of typhoid is high-in particular, countries in the Indian subcontinent. There are two typhoid vaccines available in the UK-an oral and an injectable vaccine.