The most prevelent strains of the flu are used to develop the vaccines. These may not be the same strains as the year before. Also, the flu symptoms change due to the atmosphere and climate.
By definition, antibodies act against particles, proteins, microbes, and viruses. Each antibody has to be a "match" or a "fit" to work against what it is working on. So if you have had chicken pox, you made antibodies to act against it and inactivate it. If you are exposed again, you will not get it. If you get a blood transfusion it must match or your antibodies will inactive it and will cause a reaction that will hurt you. Think of all the things you have come across: different pollen from different plants, different colds, different flu (you have to get a new shot every year as it is different), different vaccines. It just goes on and on.
The Earth completes one full orbit around the Sun approximately every 365.25 days, which defines a year. This orbital motion is responsible for the changing seasons as the Earth's tilt affects the angle and duration of sunlight received at different times of the year. The extra 0.25 days is why we have a leap year every four years, adding an extra day to the calendar in February.
The Earth climate changes every year due to increased human activity on it. The green house gases too are largely responsible for climate change every year.
There are many thousands every year
volcano kilauea has erupted every year since 1952
Yes, in fact many different vaccines exist for many different diseases (in the case of flu a new vaccine has to be made every year because the virus evolves so rapidly that the previous year's vaccine would not work against it).
Because certain viruses and bacteria evolve to become resistant to the old vaccines.
Because some vaccination are unimportant.
By definition, antibodies act against particles, proteins, microbes, and viruses. Each antibody has to be a "match" or a "fit" to work against what it is working on. So if you have had chicken pox, you made antibodies to act against it and inactivate it. If you are exposed again, you will not get it. If you get a blood transfusion it must match or your antibodies will inactive it and will cause a reaction that will hurt you. Think of all the things you have come across: different pollen from different plants, different colds, different flu (you have to get a new shot every year as it is different), different vaccines. It just goes on and on.
because the influenza bug changes every year. It's never exactly the same as the previous year.
i will say about 50,000 children die each year from vaccines
Yes, in the US horses need to be vaccinated yearly against Eastern and Western Equine Encephalitis, Tetanus, Rabies and West Nile Virus. There are other vaccines that may be recommended as well and some may be administered more than once a year.
In the year 1796.
The Games take place after the failed rebellion against the Capitol as punishment for trying to rebel against them.
Influenza is an RNA virus. Being that it is an RNA virus it has a high rate of mutation that goes unchecked. This high rate of mutation leads to different strains of the influenza virus
That depends on what the 5-way protects against. In general, once a year for the vaccinations against most diseases, but the vaccines for other diseases may need to be boostered as often as 4 times a year.
To keep your dog's vaccines updated and protected from disease, take your dog for it's injection once a year.