Potential carrier priming effect in Australian infants after 7-valent pneumococcal conjugate vaccine introduction

Table 2 Contingency table comparing the numbers of vaccine type invasive pneumococcal disease cases 9 wk after carrier primed and non-carrier primed dose of the 7-valent pneumococcal conjugate vaccine among non-Indigenous Australian infants (2001-2006)

	Two weeks after dose of 7vPCV	2-9 wk after dose of 7vPCV
Number of VT-IPD cases after carrier primed 7vPCV	4	1
Number of VT-IPD cases after non-carrier primed 7vPCV	2	6
1P value	0.08

¹One-sided fisher’s exact test. 7vPCV: 7-valent pneumococcal conjugate vaccine; VT-IPD: Vaccine type invasive pneumococcal disease.