Correlates of Protection for M Protein-Based Vaccines against Group A Streptococcus

Table 2

Variations across methods used in performing the indirect bactericidal test.

Assay component	Variations	Reference(s)
Bacteria growth phase	Stationary	[56]
	(Mid)logarithmic	[44–47]
Bacterial dilution	10^−4 with 1 : 4 serial dilution	[56]
	10^−4 with 1 : 7 serial dilution	[56]
	10^−5 with 1 : 4 serial dilution	[46, 47, 57]
Growth media	Todd-Hewitt broth only	[44–47]
	Todd-Hewitt broth + 20% normal calf/horse serum	[56]
	Serum broth	[57]
	Addition of 1% neopeptone	[56]
Serum	Heat inactivation	[47, 57]