Perform a test to assess whether the success rate is a function of the log₁₀(dilution ratio). Report a two-tailed p-value. [For the 1:10 group, log₁₀(dilution ratio) = log₁₀(1/10) = −1, . . . , etc.] 

Infectious Disease

Smallpox vaccine is highly effective in immunizing against smallpox when given as late as 2 to 3 days after exposure. Smallpox vaccine is in short supply and is currently available in different dosages. A randomized double-blind study was performed to compare the efficacy of undiluted vaccine vs. different doses of diluted vaccine [24].

One definition of clinical success was the formation of a vesicle at the inoculation site 7 to 9 days after vaccination. The results from the trial are shown in Table 10.38.

Table 10.38: Clinical success rate of various types of smallpox vaccine

Type of vaccine _________________________Success/total

Undiluted vaccine dose = 107.8 pfu/mL ___________ 19/20

1:10 diluted vaccine dose = 106.5 pfu/mL _________ 14/20

1:100 diluted vaccine dose = 105.0 pfu/mL _________ 3/20