This invention relates to a novel method for growing attenuated mutant Salmonella typhi strains lacking galactose epimerase activity and harboring a recombinant DNA molecule. The method comprises the step of culturing said Salmonella typhi strain without adding glucose to the medium during the fermentation with a starting glucose amount that is depleted before reaching the stationary phase. The invention further relates to attenuated mutant Salmonella typhi strains obtainable by said method and to an attenuated mutant Salmonella typhi strain harboring a recombinant DNA molecule encoding a VEGF receptor protein for use as a vaccine.
