Pneumococcal Conjugate Vaccines and Otitis Media: An Appraisal of the Clinical Trials

Table 2

Vaccine efficacy values in the PCV clinical trials with otitis media as an endpoint [2–4, 9, 12, 15]. Adapted with permission from Fletcher and Fritzell, 2007 Elsevier Ltd. All rights reserved [7].

		NCKP [3, 15]	FinOM [2]	FinOM [9]	Native American Trial [12]	POET [4]
Study vaccine		PCV7-CRM	PCV7-CRM	PCV7-OMPC	PCV7-CRM	PCV11-PD
Period		1995–1998	1995–1999	1995–1999	1997–2000	2000–2004
Country		USA	Finland	Finland	USA	Czech Republic, Slovakia
No. of children		37,868	1662	1666	856	4907
Age		2–24 months	2–24 months	2–24 months	6 weeks to; 24 months	6 weeks to; 24–27 months
Clinical endpoints*: vaccine efficacy, % (95% CI)
Otitis media episodes		7 (4–10)	6 (−4 to 16)	−1 (−12 to 10)	0 (−19 to 16); −3 (−21 to 12)**	34 (21–45)
Recurrent otitis media†
3/4		9 (3–15)	16 (−6 to 35)	—	5 (−52 to 41); 14 (−34 to 44)**	56 (−2 to 81)
4/5		12 (2–21)	—	—	—	—
5/6		23 (7–36)	—	—	—	—
Spontaneous perforation		—	23 (−18 to 50)	—	—	—
Risk of first tympanostomy-tube placement		20 (2–35)	4 (−19 to 23)	—	28 (−225 to 84); 22 (−256 to 83)**	60 (−27 to 88)
S. pneumoniae microbiological endpoints*: vaccine efficacy, % (95% CI)
All serotypes		—	34 (21–45)	25 (11–37)	—	52 (37–63)
Vaccine serotypes	PP	67 (—)	57 (44–67)	56 (44–66); 60 (43–72)^‡; 65 (34–81)^§	64 (−34 to 90)	58 (41–69)
	ITT	65 (—)	54 (41–64)	—	—	53 (35–66)
Cross-reactive serotypes		—	51 (27–67)	−5 (−47 to 25); −21 (−98 to 17)^‡; −25 (−88 to 49)^§	—	66 (22–88)
Any other serotypes		—	−33 (−80 to 1)	−27 (−70 to 6); −22 (−86 to 19)^‡; −146 (−405 to 20)^§	—	8 (−64 to 49)

*See Table 1 for primary otitis media endpoint, otitis media definition, myringotomy criteria, and source of MEF in each study.
**Primary efficacy group (see Section 2.3.1. Native American Trial Design and Methods).
^†Number of episodes in 6 months/number of episodes in 1 year.
^‡Among children who received PCV7-OMPC booster, during a follow-up period lasting from 12 to 24 months.
^§ Among children who received a final 12-month dose of 23-valent pneumococcal polysaccharide vaccine (Pneumovax 23 [PPSV23], Merck [West Point, PA, USA]) [9], during a follow-up period lasting from 12 to 24 months.
Reported values are rounded to whole numbers; dash line indicates not reported.
CI: confidence interval; ITT: intent to treat; PP: per-protocol.