1. Gastric acidity and the concentration of pepsin were decreased.

2. - Constructed of a high quality silicone elastomer, making it resistant to gastric acidity and sharp pieces of food.

3. Antacid, any substance, such as sodium bicarbonate, magnesium hydroxide, calcium carbonate, or aluminum hydroxide, used to counteract or neutralize gastric acids and relieve the discomfort caused by gastric acidity

4. Special technologies are required to prevent loss of viability and may include freeze drying, selected excipients to control water activity, enteric coating for protection against gastric acidity and microencapsulation.

5. • Individuals with decreased gastric acid barriers (e.g., due to achlorhydria, medications that reduce gastric acidity, antacid abuse) who travel to typhoid endemic regions should be offered either parenteral or oral immunization.

6. More than that, the vaccin adopts a kind of dosage form by special process, which could overcome the destruction from gastric acidity or pepsin, thereby render the vaccin more effective and stabler.