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.
About 90% of all tornadoes worldwide occur in the United States. More than half strike within a couple of hundred miles of Missouri and Arkansas. Tornadoes occur frequently in â¦ Missouri, Arkansas, Kansas, Oklahoma, Texas, Tennessee, and Mississippi.They are a bit less frequent in the northern plains states and Ohio Valley. Nearly every state in the USA has had tornadoes at some time.tornado alley) Why they occur is because: they get warm moist air from the gulf of Mexico that collides with cold â¦ dry air from Canada, and they get contained in this area by the mountain ranges that are on either side, when the air collides they swirl around each other causing a tornado. 2 people found this useful.