Thimerosal in Vaccines
Since the 1930s, thimerosal has been added to some vaccines and other products as a preservative because it is effective in killing bacteria and in preventing bacterial contamination, particularly in multidose containers. When thimerosal is degraded or metabolized, one product is ethyl mercury, an organic derivative of mercury. The only known side effects of receiving low doses of thimerosal in vaccines have been minor reactions such as redness and swelling at the injection site.
In July 1999, U.S. Department of Health and Human Service agencies, The American Academy of Pediatrics, and vaccine manufacturers agreed that thimerosal should be reduced or eliminated in vaccines as a precautionary measure and to reduce exposure to mercury from all sources. The decision to move toward reduced or eliminated thimerosal in vaccines was based on the various Federal guidelines for methyl mercury exposure and the assumption that the health risks from methyl and ethyl mercury were the same.

Ethyl vs. Methyl Mercury

This is a perfect explanation for normal people to understand how viruses spread. Superb!!! NPR's Robert Krulwich and medical animator David Bolinsky explain how a flu virus can trick a single cell into making a million more viruses

Early in the 2009 H1N1 influenza pandemic, an editorial in Eurosurveillance noted the importance of observing experience with this novel virus in the southern hemisphere during their usual winter influenza season [1].

This special issue of Eurosurveillance is a timely response to that call. It contains reports from the island of Réunion, South Africa, South America (Brazil, Peru), and Australia (New South Wales and Victoria). It also includes an overview of the effect of the pandemic on indigenous people. This editorial summarises some of the key findings from these papers, reviews features of pandemic H1N1 influenza epidemiology in these countries, and lists some potential lessons for the northern hemisphere (and possible future waves in the southern hemisphere).

 Important findings from the papers in this issue

Pandemic Potential of a Strain of Influenza A(H1N1):Early Findings