For example, in 1962 Japan instituted mandatory vaccination against influenza in school children. This continued until 1987 when the program was changed to optional and abandoned in 1994. Approximately 85 percent of children were estimated to have been vaccinated. <ref>http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=387431 Control of Influenza </ref> Several studies examined the mortality rates due to influenza during this period of time and revealed that the death rates due to influenza in all population groups was drastically decreased including older adult populations. Since there was no increased rate of vaccination in these populations the decreased mortality was caused by herd immunity effects of vaccinating so many children. <ref>http://www.newsrx.com/newsletters/Vaccine-Weekly/2001-04-11/200104113335VW.html Mandatory Vaccination of Japanese Schoolchildren Demonstrates "Herd Immunity" </ref> Many researchers have written that this and other evidence argues strongly for mandatory vaccination programs world wide as a means of controlling many diseases and preventing a [[pandemic]].<ref> http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1360502 Herd Immunity</ref> | For example, in 1962 Japan instituted mandatory vaccination against influenza in school children. This continued until 1987 when the program was changed to optional and abandoned in 1994. Approximately 85 percent of children were estimated to have been vaccinated. <ref>http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=387431 Control of Influenza </ref> Several studies examined the mortality rates due to influenza during this period of time and revealed that the death rates due to influenza in all population groups was drastically decreased including older adult populations. Since there was no increased rate of vaccination in these populations the decreased mortality was caused by herd immunity effects of vaccinating so many children. <ref>http://www.newsrx.com/newsletters/Vaccine-Weekly/2001-04-11/200104113335VW.html Mandatory Vaccination of Japanese Schoolchildren Demonstrates "Herd Immunity" </ref> Many researchers have written that this and other evidence argues strongly for mandatory vaccination programs world wide as a means of controlling many diseases and preventing a [[pandemic]].<ref> http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1360502 Herd Immunity</ref> |