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.
In terms of absolute tornado counts, the United States leads the list, with an average of over 1,000 tornadoes recorded each year. Canada is a distant second, with around 100 per year. Other locations that experience frequent tornado occurrences include northern Europe, western Asia, Bangladesh, Japan, Australia, New Zealand, China, South Africa, and Argentina.