Chi-Sqr Independence Test. Is vaccine effective in treating MN Strain of HIV? a= .05 New, effective AIDs vaccines are now being developed using the process of "sieving" (i.e, sifting out infections...

Chi-Sqr Independence Test. Is vaccine effective in treating MN Strain of HIV? a= .05

New, effective AIDs vaccines are now being developed using the process of "sieving" (i.e, sifting out infections with some strains of HIV). Harvard School of Public Health Statisticain Peter Gilbert demonstrated how to test the efficacy of an HIV vaccine in Chance (Fall 2000). As an example, Gilbert reported the results of VaxGen's preliminary HIV vaccine trail using the 2 X 2 table below. The vaccine was designed to eliminate a partticular strain of the virus, called "MN strain." The trail consisted of 7 AIDS patients vaccinated with the new drug and 21 AIDS patients who were treated with a placebo. The table shows the number of patients who tested postitive and negative for the MN strain in the trial follow-up period.

MN Strain