Cystitis could become a thing of the past with a new vaccine which targets E. coli, the main cause of bladder infections.

Tests of the vaccine on monkeys have proved successful and MedImmune, the company behind it, plans to conduct trials on women by the end of the year.

Women are more likely to suffer from bladder and urinary tract infections than men because they have shorter urethras.

This means bacteria has less distance to travel to reach the bladder.

About half of all women over 30 have had at least one bladder infection.

A quarter who have had an attack are plagued by recurrent bouts of infection.

Synthetic protein

The vaccine works by mimicking a protein on the surface of the E. coli bacteria, the cause of 85% of bladder and urinary tract infections.

The protein, FimH, enables the bacteria to clamp onto tissue in the bladder and cause infection.

Sol Langermann, of US-based MedImmune, told New Scientist magazine: "We've shown [FimH] is vital for infection."

Vaccinated animals make antibodies which are designed to trap the synthetic version of FimH as well as proteins made by live E. coli.

This means they cannot clamp onto tissues.

In tests on monkeys, three out of four had complete protection against infection, say the researchers.