Dried seahorse retails from US$600 to $3000 per kilogram, with larger, paler, and smoother animals commanding the highest prices. In terms of value based on weight, seahorses retail for more than the price of silver and almost that of gold in Asia.
Active immunity is stimulation of the immune system to produce antigen-specific humoral (antibody) and cellular immunity. Unlike passive immunity, which is temporary, active immunity usually lasts for many years, often for a lifetime. One way to acquire active immunity is to have the natural disease.
In studies of the four vaccines used for hepatitis A, nearly 100% of all adults who receive one develop protective levels of antibodies within one month of receiving a single dose. In addition, eight years after receiving two or more doses, 99% to 100% of vaccinated individuals were still fully protected. Results are similar for the hepatitis B vaccine, and experts estimate that both vaccines will give immunity for up to 20 or 30 years and possibly for life. As with all medications, there is the potential for side effects. But the safety record of both vaccines is outstanding.