Table 1.
Characteristics of study participants by VT (IPD caused by serotypes included in PCV13) and NVT IPD (IPD caused by non-PCV13 serotype) stratified by study period.
| Full study period | Early PCV13 implementation | Late PCV13 implementation | ||||
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| May 1, 2010 - Dec 31 2019 | May 1, 2010 - May 31 2014 | June 1, 2014 - Dec 31 2019 | ||||
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| VT | NVT | VT | NVT | VT | NVT | |
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| N (%) | N (%) | N (%) | N (%) | N (%) | N (%) | |
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| N = 223 | N = 938 | N = 104 | N = 420 | N = 119 | N = 518 | |
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| Age group | ||||||
| 2–6 months | 44 (19.7) | 153 (16.3) | 26 (25.0) | 68 (16.2) | 18 (15.1) | 85 (16.4) |
| 7–11 months | 26 (11.7) | 166 (17.7) | 15 (14.4) | 80 (19.0) | 11 (9.2) | 86 (16.6) |
| 12–23 months | 49 (22.0) | 292 (31.1) | 23 (22.1) | 139 (33.1) | 26 (21.8) | 153 (29.5) |
| 24–59 months | 104 (46.6) | 327 (34.9) | 40 (38.5) | 133 (31.7) | 64 (53.8) | 194 (37.5) |
| Sex | ||||||
| Male | 133 (59.6) | 544 (58.0) | 56 (53.8) | 233 (55.5) | 77 (64.7) | 311 (60.0) |
| Female | 90 (40.4) | 394 (42.0) | 48 (46.2) | 187 (44.5) | 42 (35.3) | 207 (40.0) |
| Race and ethnicity | ||||||
| White, non-Hispanic | 89 (39.9) | 418 (44.6) | 35 (33.7) | 175 (41.7) | 54 (45.4) | 243 (46.9) |
| Black, non-Hispanic | 58 (26.0) | 274 (29.2) | 21 (20.2) | 118 (28.1) | 37 (31.1) | 156 (30.1) |
| American Indian/ Alaska Native, non-Hispanic | 7 (3.1) | 16 (1.7) | 3 (2.9) | 9 (2.1) | 4 (3.4) | 7 (1.4) |
| Asian/Pacific Islander, non-Hispanic | 11 (4.9) | 53 (5.7) | 5 (4.8) | 25 (6.0) | 6 (5.0) | 28 (5.4) |
| Unknown race, non-Hispanic | 2 (0.9) | 4 (0.4) | 2 (1.9) | 4 (1.0) | 3 (2.5) | 11 (2.1) |
| Hispanic | 4 (1.8) | 14 (1.5) | 1 (1.0) | 3 (0.7) | 15 (12.6) | 73 (14.1) |
| Calendar year | ||||||
| 2010 | 16 (7.2) | 28 (3.0) | 16 (15.4) | 28 (6.7) | - - | - - |
| 2011 | 23 (10.3) | 111 (11.8) | 23 (22.1) | 111 (26.4) | - - | - - |
| 2012 | 22 (9.9) | 99 (10.6) | 22 (21.2) | 99 (23.6) | - - | - - |
| 2013 | 26 (11.7) | 128 (13.6) | 26 (25.0) | 128 (30.5) | - - | - - |
| 2014 | 29 (13.0) | 113 (12.0) | 17 (16.3) | 54 (12.9) | 12 (10.1) | 59 (11.4) |
| 2015 | 25 (11.2) | 102 (10.9) | - - | - - | 25 (21.0) | 102 (19.7) |
| 2016 | 23 (10.3) | 103 (11.0) | - - | - - | 23 (19.3) | 103 (19.9) |
| 2017 | 23 (10.3) | 79 (8.4) | - - | - - | 23 (19.3) | 79 (15.3) |
| 2018 | 21 (9.4) | 89 (9.5) | - - | - - | 21 (17.6) | 89 (17.2) |
| 2019 | 15 (6.7) | 86 (9.2) | - - | - - | 15 (12.6) | 86 (16.6) |
| Underlying conditions | ||||||
| Chronic conditions1 | 17 (8.5) | 85 (10.1) | 8 (7.7) | 38 (9.0) | 9 (9.5) | 47 (11.2) |
| Immunocompromising conditions 2 | 7 (3.5) | 64 (7.7) | 2 (1.9) | 19 (4.5) | 5 (5.3) | 45 (10.9) |
| Asthma | 28 (13.5) | 121 (14.2) | 20 (19.2) | 81 (19.3) | 8 (7.7) | 40 (9.2) |
| PCV history3 | ||||||
| No doses of any PCV4 | 47 (21.1) | 53 (5.7) | 18 (17.3) | 21 (5.0) | 29 (24.4) | 32 (6.2) |
| ≥1 dose PCV13 | 176 (78.9) | 885 (94.3) | 86 (82.7) | 399 (95.0) | 90 (75.6) | 486 (93.8) |
| ≥1 dose PCV13, 0 PCV7 doses | 145 (82.4) | 768 (86.8) | 56 (65.1) | 283 (70.9) | 89 (98.9) | 485 (99.8) |
| ≥1 dose PCV13 + ≥1 PCV7 doses | 31 (17.6) | 117 (13.2) | 30 (34.9) | 116 (29.1) | 1 (1.1) | 1 (0.2) |
| ≥3 doses PCV13 | 108 (48.4) | 600 (64.0) | 35 (33.7) | 223 (53.1) | 73 (61.3) | 377 (72.8) |
| ≥3 doses PCV13, 0 PCV7 doses | 104 (96.3) | 589 (98.2) | 31 (88.6) | 212 (95.1) | 73 (100.0) | 377 (100.0) |
| ≥3 doses PCV13 + ≥1 PCV7 doses | 4 (3.7) | 11 (1.8) | 4 (11.4) | 11 (4.9) | 0 (0) | 0 (0) |
| PCV13 vaccination schedule Infant schedule5 | ||||||
| 1 + 0: One dose < 12 mo | 27 (12.1) | 86 (9.2) | 18 (17.3) | 30 (7.1) | 9 (7.6) | 56 (10.8) |
| 2 + 0: Two doses < 12 mo | 13 (5.8) | 77 (8.2) | 7 (6.7) | 36 (8.6) | 6 (5.0) | 41 (7.9) |
| 3 + 0: Three doses < 12 mo | 24 (10.8) | 217 (23.1) | 13 (12.5) | 100 (23.8) | 11 (9.2) | 117 (22.6) |
| 2 + 1: Two dose < 12 + 1 dose ≥ 12 mo | 4 (1.8) | 19 (2.0) | 0 (0.0) | 2 (0.5) | 4 (3.4) | 17 (3.3) |
| 3 + 1: Three doses < 12 + 1 dose ≥ 12 mo | 73 (32.7) | 346 (36.9) | 18 (17.3) | 108 (25.7) | 55 (46.2) | 238 (45.9) |
| Toddler doses (≥12 mo)6 | 0 (0.0) | 12 (1.2) | 0 (0.0) | 4 (1.0) | 0 (0.0) | 8 (1.8) |
Abbreviations: VE = Vaccine Effectiveness; PCV = pneumococcal conjugate vaccine; PCV13- 13-valent pneumococcal conjugate vaccine; VT = PCV13 vaccine type serotypes, including serotype 6C due to cross protection with 6A; NVT = non-vaccine type, serotypes not included in PCV123.
Chronic conditions were defined a priori and include: Congestive heart failure (chronic heart disease), Cardiomyopathies (chronic heart disease), Chronic liver disease, Chronic obstructive pulmonary disease (chronic lung disease), Emphysema (chronic lung disease). Proportions are calculated out of the total number of individuals who are not missing data for chronic, immunocompromising or asthma.
Immunocompromising conditions were defined a priori and include: Congenital or acquired asplenia, Sickle cell disease or other hemoglobinopathies, Chronic renal failure, Congenital or acquired immunodeficiencies, Generalized malignancy, HIV infection, Hodgkin disease, iatrogenic immunosuppression, Leukemia, Lymphoma, Multiple myeloma, Nephrotic syndrome, Solid organ transplant.
The primary exposure is receipt of at least one dose of PCV13 given after 6 weeks of age, at least 4 weeks after the previous dose of PCV7 or PCV13 (if ≥ 1 dose given), and at least 2 weeks before the culture date, versus receipt of no pneumococcal vaccines. Participants who received PCV7 doses are excluded from the primary analysis. Characteristics of the study population including participants who received PCV7 only are outlined in Table S2.
The distribution of age among children receiving zero PCV doses (N = 100) was N = 46, 2–6 months; N = 16, 7–11 months; N = 22, 12–23 months; N = 16; 25–59 months. N = 63 of the children were male. N = 51 children were white, non-Hispanic; N = 26 black, non-Hispanic; N = 16 % Hispanic; N = 7 other race/ethnicity. The proportion of participants with no doses by study year are summarized in Table S5.
Counts may not sum to total (N = 1161) because some children did not receive their doses of PCV13 in any of these schedules and are excluded (N = 263). Participants who received PCV7 were excluded from this analysis (Table S1). Of note, the median days between a participant’s fourth dose of PCV13 and their pneumococcal culture during the early and late PCV13 implementation period was 245 (range: 15–1132) and 605 (range: 14–1436), respectively.
Represents children who received one or more doses of PCV13 at 12 months of age or older and no prior doses of PCV7. Among the N = 12 participants, 4 received one toddler dose and 8 received 2 toddler doses.