SARS-CoV-2 Anti-S IgG and neutAb Results for Participants and Their Infants at First Sample Collection, Delivery, and <3 and 3–6 Months Postpartum, Overall and by Maternal Vaccination Statusa
| Maternal Antibody Responses . | Infant Antibody Responses . | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| . | Maternal Vaccination Status at Time of Blood Collection . | Sample . | Maternal Vaccination Status at Time of Delivery . | ||||||||||||
| . | Total . | Infection Onlyb . | Hybrid Immunityb . | . | . | Total . | Infection Only . | Hybrid Immunity . | . | ||||||
| Sample . | N . | n (%) or Median (IQR) . | N . | n (%) or Median (IQR) . | N . | n (%) or Median (IQR) . | P Value . | . | N . | n (%) or Median (IQR) . | N . | n (%) or Median (IQR) . | N . | n (%) or Median (IQR) . | P Value . |
| Pregnancy | 69 | 30 (43) | 39 (57) | NA | |||||||||||
| Anti-S IgG+ | 69 | 67 (97) | 30 | 28 (93) | 39 | 39 (100) | .10 | ||||||||
| Log10 AU/mLc,d | 67 | 4.40e (2.89–4.40) | 28 | 2.72 (2.37–3.06) | 39 | 4.40 (4.40–4.40) | <.01 | ||||||||
| neutAb+ | 67 | 62 (93) | 30 | 25 (83) | 37 | 37 (100) | .01 | ||||||||
| Log10 ND50d | 62 | 3.88e (2.48–4.00) | 25 | 2.33 (1.97–2.60) | 37 | 4.00 (4.00–4.00) | <.01 | ||||||||
| Deliveryf | 89 | 26 (29) | 63 (71) | Birth, cord | 82 | 22 (27) | 60 (73) | ||||||||
| Anti-S IgG+ | 86 | 83 (97) | 23 | 20 (87) | 63 | 63 (100) | <.01 | 80 | 77 (96) | 21 | 18 (86) | 59 | 59 (100) | <.01 | |
| Log10 AU/mL | 83 | 4.40 (3.37–4.40) | 20 | 2.93 (2.55–3.10) | 63 | 4.40 (4.40–4.40) | <.01 | 77 | 4.40 (3.86–4.40) | 18 | 2.95 (2.38–3.34) | 59 | 4.40 (4.40–4.40) | <.01 | |
| neutAb+ | 64 | 61 (95) | 22 | 19 (86) | 42 | 42 (100) | .01 | 59 | 54 (92) | 20 | 15 (75) | 39 | 39 (100) | <.01 | |
| Log10 ND50 | 61 | 4.00 (2.62–4.00) | 19 | 2.45 (2.04–2.80) | 42 | 3.95 (3.62–4.00) | <.01 | 54 | 3.93 (2.83–4.00) | 15 | 2.37 (2.03–2.68) | 39 | 4.00 (3.76–4.00) | <.01 | |
| <3 mo PP | 52 | 11 (21) | 41 (79) | <3 mo of age | 47 | 16 (34) | 31 (66) | ||||||||
| Anti-S IgG+ | 50 | 50 (100) | 9 | 9 (100) | 41 | 41 (100) | … | 45 | 44 (98) | 14 | 13 (93) | 31 | 31 (100) | .13 | |
| Log10 AU/mL | 50 | 4.40 (3.75–4.40) | 9 | 3.09 (2.45–3.34) | 41 | 4.40 (4.40–4.40) | <.01 | 44 | 4.20 (2.92–4.40) | 13 | 2.09 (1.89–2.74) | 31 | 4.40 (4.17–4.40) | <.01 | |
| neutAb+ | 34 | 33 (97) | 9 | 8 (89) | 25 | 25 (100) | .09 | 32 | 24 (75) | 14 | 6 (43) | 18 | 18 (100) | <.01 | |
| Log10 ND50 | 33 | 3.94 (3.02–4.00) | 8 | 2.62 (2.17–3.01) | 25 | 4.00 (3.78–4.00) | <.01 | 24 | 3.58 (2.58–3.65) | 6 | 1.97 (1.72–2.10) | 18 | 3.62 (3.36–3.68) | <.01 | |
| 3–6 mo PP | 33 | 4 (12) | 29 (88) | 3–6 mo of age | 29 | 9 (31) | 20 (69) | ||||||||
| Anti-S IgG+ | 32 | 32 (100) | 4 | 4 (100) | 28 | 28 (100) | … | 28 | 24 (86) | 8 | 4 (50) | 20 | 20 (100) | <.01 | |
| Log10 AU/mL | 32 | 4.40 (4.29–4.40) | 4 | 3.05 (2.65–3.57) | 28 | 4.40 (4.28–4.40) | <.01 | 24 | 3.82 (3.15–3.95) | 4 | 1.95 (1.81–2.07) | 20 | 3.84 (3.66–3.98) | <.01 | |
| neutAb+ | 23 | 23 (100) | 4 | 4 (100) | 19 | 19 (100) | … | 18 | 12 (67) | 7 | 1 (14) | 11 | 11 (100) | <.01 | |
| Log10 ND50 | 23 | 3.73 (3.44–3.95) | 4 | 2.82 (2.41–3.38) | 19 | 3.79 (3.58–4.00) | .02 | 12 | 3.09 (2.62–3.38) | 1 | 1.34 | 11 | 3.20 (2.65–3.42) | .11 | |
| Maternal Antibody Responses . | Infant Antibody Responses . | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| . | Maternal Vaccination Status at Time of Blood Collection . | Sample . | Maternal Vaccination Status at Time of Delivery . | ||||||||||||
| . | Total . | Infection Onlyb . | Hybrid Immunityb . | . | . | Total . | Infection Only . | Hybrid Immunity . | . | ||||||
| Sample . | N . | n (%) or Median (IQR) . | N . | n (%) or Median (IQR) . | N . | n (%) or Median (IQR) . | P Value . | . | N . | n (%) or Median (IQR) . | N . | n (%) or Median (IQR) . | N . | n (%) or Median (IQR) . | P Value . |
| Pregnancy | 69 | 30 (43) | 39 (57) | NA | |||||||||||
| Anti-S IgG+ | 69 | 67 (97) | 30 | 28 (93) | 39 | 39 (100) | .10 | ||||||||
| Log10 AU/mLc,d | 67 | 4.40e (2.89–4.40) | 28 | 2.72 (2.37–3.06) | 39 | 4.40 (4.40–4.40) | <.01 | ||||||||
| neutAb+ | 67 | 62 (93) | 30 | 25 (83) | 37 | 37 (100) | .01 | ||||||||
| Log10 ND50d | 62 | 3.88e (2.48–4.00) | 25 | 2.33 (1.97–2.60) | 37 | 4.00 (4.00–4.00) | <.01 | ||||||||
| Deliveryf | 89 | 26 (29) | 63 (71) | Birth, cord | 82 | 22 (27) | 60 (73) | ||||||||
| Anti-S IgG+ | 86 | 83 (97) | 23 | 20 (87) | 63 | 63 (100) | <.01 | 80 | 77 (96) | 21 | 18 (86) | 59 | 59 (100) | <.01 | |
| Log10 AU/mL | 83 | 4.40 (3.37–4.40) | 20 | 2.93 (2.55–3.10) | 63 | 4.40 (4.40–4.40) | <.01 | 77 | 4.40 (3.86–4.40) | 18 | 2.95 (2.38–3.34) | 59 | 4.40 (4.40–4.40) | <.01 | |
| neutAb+ | 64 | 61 (95) | 22 | 19 (86) | 42 | 42 (100) | .01 | 59 | 54 (92) | 20 | 15 (75) | 39 | 39 (100) | <.01 | |
| Log10 ND50 | 61 | 4.00 (2.62–4.00) | 19 | 2.45 (2.04–2.80) | 42 | 3.95 (3.62–4.00) | <.01 | 54 | 3.93 (2.83–4.00) | 15 | 2.37 (2.03–2.68) | 39 | 4.00 (3.76–4.00) | <.01 | |
| <3 mo PP | 52 | 11 (21) | 41 (79) | <3 mo of age | 47 | 16 (34) | 31 (66) | ||||||||
| Anti-S IgG+ | 50 | 50 (100) | 9 | 9 (100) | 41 | 41 (100) | … | 45 | 44 (98) | 14 | 13 (93) | 31 | 31 (100) | .13 | |
| Log10 AU/mL | 50 | 4.40 (3.75–4.40) | 9 | 3.09 (2.45–3.34) | 41 | 4.40 (4.40–4.40) | <.01 | 44 | 4.20 (2.92–4.40) | 13 | 2.09 (1.89–2.74) | 31 | 4.40 (4.17–4.40) | <.01 | |
| neutAb+ | 34 | 33 (97) | 9 | 8 (89) | 25 | 25 (100) | .09 | 32 | 24 (75) | 14 | 6 (43) | 18 | 18 (100) | <.01 | |
| Log10 ND50 | 33 | 3.94 (3.02–4.00) | 8 | 2.62 (2.17–3.01) | 25 | 4.00 (3.78–4.00) | <.01 | 24 | 3.58 (2.58–3.65) | 6 | 1.97 (1.72–2.10) | 18 | 3.62 (3.36–3.68) | <.01 | |
| 3–6 mo PP | 33 | 4 (12) | 29 (88) | 3–6 mo of age | 29 | 9 (31) | 20 (69) | ||||||||
| Anti-S IgG+ | 32 | 32 (100) | 4 | 4 (100) | 28 | 28 (100) | … | 28 | 24 (86) | 8 | 4 (50) | 20 | 20 (100) | <.01 | |
| Log10 AU/mL | 32 | 4.40 (4.29–4.40) | 4 | 3.05 (2.65–3.57) | 28 | 4.40 (4.28–4.40) | <.01 | 24 | 3.82 (3.15–3.95) | 4 | 1.95 (1.81–2.07) | 20 | 3.84 (3.66–3.98) | <.01 | |
| neutAb+ | 23 | 23 (100) | 4 | 4 (100) | 19 | 19 (100) | … | 18 | 12 (67) | 7 | 1 (14) | 11 | 11 (100) | <.01 | |
| Log10 ND50 | 23 | 3.73 (3.44–3.95) | 4 | 2.82 (2.41–3.38) | 19 | 3.79 (3.58–4.00) | .02 | 12 | 3.09 (2.62–3.38) | 1 | 1.34 | 11 | 3.20 (2.65–3.42) | .11 | |
Abbreviations: Anti-S IgG+, anti-spike immunoglobulin G positive; IQR, interquartile range; PP, months postpartum; ND50, 50% neutralization dose; neutAb+, neutralizing antibody positive; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2; NA, not applicable; N, population size; n, sample size.
Bold values indicate P<0.05.
aMaternal vaccine status at delivery.
bInfection only was classified as no history of an mRNA vaccine or viral vector vaccine against SARS-CoV-2; hybrid immunity was defined as confirmed SARS-CoV-2 infection and at least 1 dose of an mRNA or viral vector vaccine.
cND50 and anti-S (AU/mL) medians are among positives.
dLog10 upper limit of quantification for Abbott anti-S is 4.40 and 4.00 for neutAb assay ND50.
ePositive threshold for anti-S IgG+ ≥ 50 AU/mL and neutAb+ ND50 ≥ 20 and R2 ≥ 0.9.
fThirty-four participants had initial sample collected at delivery; 4 participants had their first sample collected early postpartum (range, 2–13 weeks) after delivery.
SARS-CoV-2 Anti-S IgG and neutAb Results for Participants and Their Infants at First Sample Collection, Delivery, and <3 and 3–6 Months Postpartum, Overall and by Maternal Vaccination Statusa
| Maternal Antibody Responses . | Infant Antibody Responses . | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| . | Maternal Vaccination Status at Time of Blood Collection . | Sample . | Maternal Vaccination Status at Time of Delivery . | ||||||||||||
| . | Total . | Infection Onlyb . | Hybrid Immunityb . | . | . | Total . | Infection Only . | Hybrid Immunity . | . | ||||||
| Sample . | N . | n (%) or Median (IQR) . | N . | n (%) or Median (IQR) . | N . | n (%) or Median (IQR) . | P Value . | . | N . | n (%) or Median (IQR) . | N . | n (%) or Median (IQR) . | N . | n (%) or Median (IQR) . | P Value . |
| Pregnancy | 69 | 30 (43) | 39 (57) | NA | |||||||||||
| Anti-S IgG+ | 69 | 67 (97) | 30 | 28 (93) | 39 | 39 (100) | .10 | ||||||||
| Log10 AU/mLc,d | 67 | 4.40e (2.89–4.40) | 28 | 2.72 (2.37–3.06) | 39 | 4.40 (4.40–4.40) | <.01 | ||||||||
| neutAb+ | 67 | 62 (93) | 30 | 25 (83) | 37 | 37 (100) | .01 | ||||||||
| Log10 ND50d | 62 | 3.88e (2.48–4.00) | 25 | 2.33 (1.97–2.60) | 37 | 4.00 (4.00–4.00) | <.01 | ||||||||
| Deliveryf | 89 | 26 (29) | 63 (71) | Birth, cord | 82 | 22 (27) | 60 (73) | ||||||||
| Anti-S IgG+ | 86 | 83 (97) | 23 | 20 (87) | 63 | 63 (100) | <.01 | 80 | 77 (96) | 21 | 18 (86) | 59 | 59 (100) | <.01 | |
| Log10 AU/mL | 83 | 4.40 (3.37–4.40) | 20 | 2.93 (2.55–3.10) | 63 | 4.40 (4.40–4.40) | <.01 | 77 | 4.40 (3.86–4.40) | 18 | 2.95 (2.38–3.34) | 59 | 4.40 (4.40–4.40) | <.01 | |
| neutAb+ | 64 | 61 (95) | 22 | 19 (86) | 42 | 42 (100) | .01 | 59 | 54 (92) | 20 | 15 (75) | 39 | 39 (100) | <.01 | |
| Log10 ND50 | 61 | 4.00 (2.62–4.00) | 19 | 2.45 (2.04–2.80) | 42 | 3.95 (3.62–4.00) | <.01 | 54 | 3.93 (2.83–4.00) | 15 | 2.37 (2.03–2.68) | 39 | 4.00 (3.76–4.00) | <.01 | |
| <3 mo PP | 52 | 11 (21) | 41 (79) | <3 mo of age | 47 | 16 (34) | 31 (66) | ||||||||
| Anti-S IgG+ | 50 | 50 (100) | 9 | 9 (100) | 41 | 41 (100) | … | 45 | 44 (98) | 14 | 13 (93) | 31 | 31 (100) | .13 | |
| Log10 AU/mL | 50 | 4.40 (3.75–4.40) | 9 | 3.09 (2.45–3.34) | 41 | 4.40 (4.40–4.40) | <.01 | 44 | 4.20 (2.92–4.40) | 13 | 2.09 (1.89–2.74) | 31 | 4.40 (4.17–4.40) | <.01 | |
| neutAb+ | 34 | 33 (97) | 9 | 8 (89) | 25 | 25 (100) | .09 | 32 | 24 (75) | 14 | 6 (43) | 18 | 18 (100) | <.01 | |
| Log10 ND50 | 33 | 3.94 (3.02–4.00) | 8 | 2.62 (2.17–3.01) | 25 | 4.00 (3.78–4.00) | <.01 | 24 | 3.58 (2.58–3.65) | 6 | 1.97 (1.72–2.10) | 18 | 3.62 (3.36–3.68) | <.01 | |
| 3–6 mo PP | 33 | 4 (12) | 29 (88) | 3–6 mo of age | 29 | 9 (31) | 20 (69) | ||||||||
| Anti-S IgG+ | 32 | 32 (100) | 4 | 4 (100) | 28 | 28 (100) | … | 28 | 24 (86) | 8 | 4 (50) | 20 | 20 (100) | <.01 | |
| Log10 AU/mL | 32 | 4.40 (4.29–4.40) | 4 | 3.05 (2.65–3.57) | 28 | 4.40 (4.28–4.40) | <.01 | 24 | 3.82 (3.15–3.95) | 4 | 1.95 (1.81–2.07) | 20 | 3.84 (3.66–3.98) | <.01 | |
| neutAb+ | 23 | 23 (100) | 4 | 4 (100) | 19 | 19 (100) | … | 18 | 12 (67) | 7 | 1 (14) | 11 | 11 (100) | <.01 | |
| Log10 ND50 | 23 | 3.73 (3.44–3.95) | 4 | 2.82 (2.41–3.38) | 19 | 3.79 (3.58–4.00) | .02 | 12 | 3.09 (2.62–3.38) | 1 | 1.34 | 11 | 3.20 (2.65–3.42) | .11 | |
| Maternal Antibody Responses . | Infant Antibody Responses . | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| . | Maternal Vaccination Status at Time of Blood Collection . | Sample . | Maternal Vaccination Status at Time of Delivery . | ||||||||||||
| . | Total . | Infection Onlyb . | Hybrid Immunityb . | . | . | Total . | Infection Only . | Hybrid Immunity . | . | ||||||
| Sample . | N . | n (%) or Median (IQR) . | N . | n (%) or Median (IQR) . | N . | n (%) or Median (IQR) . | P Value . | . | N . | n (%) or Median (IQR) . | N . | n (%) or Median (IQR) . | N . | n (%) or Median (IQR) . | P Value . |
| Pregnancy | 69 | 30 (43) | 39 (57) | NA | |||||||||||
| Anti-S IgG+ | 69 | 67 (97) | 30 | 28 (93) | 39 | 39 (100) | .10 | ||||||||
| Log10 AU/mLc,d | 67 | 4.40e (2.89–4.40) | 28 | 2.72 (2.37–3.06) | 39 | 4.40 (4.40–4.40) | <.01 | ||||||||
| neutAb+ | 67 | 62 (93) | 30 | 25 (83) | 37 | 37 (100) | .01 | ||||||||
| Log10 ND50d | 62 | 3.88e (2.48–4.00) | 25 | 2.33 (1.97–2.60) | 37 | 4.00 (4.00–4.00) | <.01 | ||||||||
| Deliveryf | 89 | 26 (29) | 63 (71) | Birth, cord | 82 | 22 (27) | 60 (73) | ||||||||
| Anti-S IgG+ | 86 | 83 (97) | 23 | 20 (87) | 63 | 63 (100) | <.01 | 80 | 77 (96) | 21 | 18 (86) | 59 | 59 (100) | <.01 | |
| Log10 AU/mL | 83 | 4.40 (3.37–4.40) | 20 | 2.93 (2.55–3.10) | 63 | 4.40 (4.40–4.40) | <.01 | 77 | 4.40 (3.86–4.40) | 18 | 2.95 (2.38–3.34) | 59 | 4.40 (4.40–4.40) | <.01 | |
| neutAb+ | 64 | 61 (95) | 22 | 19 (86) | 42 | 42 (100) | .01 | 59 | 54 (92) | 20 | 15 (75) | 39 | 39 (100) | <.01 | |
| Log10 ND50 | 61 | 4.00 (2.62–4.00) | 19 | 2.45 (2.04–2.80) | 42 | 3.95 (3.62–4.00) | <.01 | 54 | 3.93 (2.83–4.00) | 15 | 2.37 (2.03–2.68) | 39 | 4.00 (3.76–4.00) | <.01 | |
| <3 mo PP | 52 | 11 (21) | 41 (79) | <3 mo of age | 47 | 16 (34) | 31 (66) | ||||||||
| Anti-S IgG+ | 50 | 50 (100) | 9 | 9 (100) | 41 | 41 (100) | … | 45 | 44 (98) | 14 | 13 (93) | 31 | 31 (100) | .13 | |
| Log10 AU/mL | 50 | 4.40 (3.75–4.40) | 9 | 3.09 (2.45–3.34) | 41 | 4.40 (4.40–4.40) | <.01 | 44 | 4.20 (2.92–4.40) | 13 | 2.09 (1.89–2.74) | 31 | 4.40 (4.17–4.40) | <.01 | |
| neutAb+ | 34 | 33 (97) | 9 | 8 (89) | 25 | 25 (100) | .09 | 32 | 24 (75) | 14 | 6 (43) | 18 | 18 (100) | <.01 | |
| Log10 ND50 | 33 | 3.94 (3.02–4.00) | 8 | 2.62 (2.17–3.01) | 25 | 4.00 (3.78–4.00) | <.01 | 24 | 3.58 (2.58–3.65) | 6 | 1.97 (1.72–2.10) | 18 | 3.62 (3.36–3.68) | <.01 | |
| 3–6 mo PP | 33 | 4 (12) | 29 (88) | 3–6 mo of age | 29 | 9 (31) | 20 (69) | ||||||||
| Anti-S IgG+ | 32 | 32 (100) | 4 | 4 (100) | 28 | 28 (100) | … | 28 | 24 (86) | 8 | 4 (50) | 20 | 20 (100) | <.01 | |
| Log10 AU/mL | 32 | 4.40 (4.29–4.40) | 4 | 3.05 (2.65–3.57) | 28 | 4.40 (4.28–4.40) | <.01 | 24 | 3.82 (3.15–3.95) | 4 | 1.95 (1.81–2.07) | 20 | 3.84 (3.66–3.98) | <.01 | |
| neutAb+ | 23 | 23 (100) | 4 | 4 (100) | 19 | 19 (100) | … | 18 | 12 (67) | 7 | 1 (14) | 11 | 11 (100) | <.01 | |
| Log10 ND50 | 23 | 3.73 (3.44–3.95) | 4 | 2.82 (2.41–3.38) | 19 | 3.79 (3.58–4.00) | .02 | 12 | 3.09 (2.62–3.38) | 1 | 1.34 | 11 | 3.20 (2.65–3.42) | .11 | |
Abbreviations: Anti-S IgG+, anti-spike immunoglobulin G positive; IQR, interquartile range; PP, months postpartum; ND50, 50% neutralization dose; neutAb+, neutralizing antibody positive; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2; NA, not applicable; N, population size; n, sample size.
Bold values indicate P<0.05.
aMaternal vaccine status at delivery.
bInfection only was classified as no history of an mRNA vaccine or viral vector vaccine against SARS-CoV-2; hybrid immunity was defined as confirmed SARS-CoV-2 infection and at least 1 dose of an mRNA or viral vector vaccine.
cND50 and anti-S (AU/mL) medians are among positives.
dLog10 upper limit of quantification for Abbott anti-S is 4.40 and 4.00 for neutAb assay ND50.
ePositive threshold for anti-S IgG+ ≥ 50 AU/mL and neutAb+ ND50 ≥ 20 and R2 ≥ 0.9.
fThirty-four participants had initial sample collected at delivery; 4 participants had their first sample collected early postpartum (range, 2–13 weeks) after delivery.
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