Children who are not vaccinated by 2 years of age can be vaccinated at later visits. For others at risk, the hepatitis A vaccine series may be started whenever a person wishes to be protected or is at risk of infection.For travelers, it is best to start the vaccine series at least one month before traveling.(Some protection may still result if the vaccine is given on or closer to the travel date.).epatitis A is a serious liver disease caused by the hepatitis A virus (HAV). HAV is found in the stool of people with hepatitis A. It is usually spread by close personal contact and sometimes by eating food or drinking water containing HAV.
Poaching, overgrazing and clearing of the land for crops are the main threats. About 16 percent of tropical grasslands have been converted for agriculture or urban development. Desertification is also a significant threat.nimals. Tropical grassland animals (which do not all occur in the same area) include giraffes, zebras, buffaloes, kangaroos, mice, moles, gophers, ground squirrels, snakes, worms, termites, beetles, lions, leopards, hyenas, and elephants.
grassland: major grasslands of the world. The three types of grasslands of the world are prairie, steppe, and savanna. Little of the original prairie still bears a mantle of tall grass.Instead, farmers raise a variety of crops on its rich soil.The moister portions of the steppe are cultivated, and the rest is valuable pasture.rassland: major grasslands of the world. The three types of grasslands of the world are prairie, steppe, and savanna. Little of the original prairie still bears a mantle of tall grass.