In some cases, these vaccines use epitopesâthe very specific parts of the antigen that antibodies or T cells recognize and bind to. Because subunit vaccines contain only the essential antigens and not all the other molecules that make up the microbe, the chances of adverse reactions to the vaccine are lower.
Tornadoes occur in many parts of the world, including Australia, Europe, Africa, Asia, and South America. Even New Zealand reports about 20 tornadoes each year. Two of the highest concentrations of tornadoes outside the U.S. are Argentina and Bangladesh.
Tornadoes are more common in United States than in any other country. The United States receives more than 1,200 tornadoes annuallyâfour times the amount seen in Europe. Violent tornadoesâthose rated EF4 or EF5 on the Enhanced Fujita Scaleâoccur more often in the United States than in any other country. Most tornadoes in the United States occur east of the Rocky Mountains. The Great Plains, the Midwest, the Mississippi Valley and the southern United States are all areas that are ...