Table 1.
Anti-spike IgG concentrations (GMC, 95%CI) in unvaccinated seropositive mothers following each wave of SARS-CoV-2. Mothers are stratified by their serostatus prior to the wave.
| Post Wave 1 | Post Wave 2** |
Post Wave 3*** |
Post Wave 4**** |
|||||||
|---|---|---|---|---|---|---|---|---|---|---|
| All (n=339) | Seronegative pre-wave 1 (n=163) | Seropositive pre-wave 1 (n=174) | All (n=337) | Seronegative pre-wave 2(n=68) | Seropositive Pre-wave 2 (n=176) | All (n=244) | Seronegative pre-wave 3(n=22) | Seropositive Pre-wave 3 (n=163) | All (n=185) | |
| Seropositive n (%) | 176 (51·9%) |
84 (51·5%) |
166 (95·4%) |
250 (74·2%)# |
45 (66·2%) |
174 (98·9%) |
219 (89·8%)# |
17 (77·3%) |
163 (100%) |
180 (97·3%) |
| GMCS (95% CI) in seropositive mothers | ||||||||||
| S-Ancestral | 30·58 (23·77;39·4) |
19·79 (14·83;26·41) |
32·40 (25·87;40·58) |
27·45 (22·95;32·85) |
55·15 (37·81;80·48) |
72·13 (54·94;94·71) |
68·26 (54·28; 85·84) |
138·01 (42·11;452·33) | 502·62 (383·49;658·76) |
444·87 (339·35;583·20) |
| S-Beta | 14·25 (11·03;18·41) |
30·09 (21·07;42·99) |
17·60 (13·97;22·18) |
21·08 (17·33;25·64) |
46·37 (32·16;66·85) |
58·97 (44·58;78·00) |
56·13 (44·42; 70·91) |
102·17 (35·20; 296·57) | 359·38 (273·49;472·24) |
319·13 (243·89;417·57) |
| S-Delta | 11·53 (8·94; 14·86) |
11·51 (8·43; 15·72) |
13·47 (10·59;17·14) |
12·75 (10·55;15·42) |
64·70 (42·99;97·39) |
49·21 (36·98;65·48) |
52·05 (40·90; 66·25) |
76·49 (25·61; 228·43) | 325·97 (248·82;427·04) |
284·26 (217·22;372·00) |
| S-Omicron | 5·23 (4·12; 6·63) |
5.86 (4·39; 7·83) |
5·60 (4·41; 7·11) |
5·69 (4·73; 6·84) |
11·69 (8·84; 16·21) † |
21·55 (16·33;28·45) |
18·88 (15·00;23·77)*** |
126·23 (50·65; 314·59) | 183·25 (136·91;245·28) |
176·91 (134·31;233·03) |
| S-Beta: S-ancestral | 0·47 | 1·52 | 0·54 | n/a | 0·84 | 0·82 | n/a | 0·74 | 0·72 | n/a |
| S-Delta: S-ancestral | 0·38 | 0·58 | 0·42 | n/a | 1·17 | 0·68 | n/a | 0·55 | 0·65 | n/a |
| S-Omicron: S-Ancestral | 0·17 | 0·30 | 0·17 | n/a | 0·21 | 0·30 | n/a | 0·91 | 0·36 | n/a |
S = Spike protein; GMCs = geometric mean concentration; CI = confidence interval; S-ancestral– spike antibodies to ancestral SARSCoV2 virus; S-beta = Spike antibodies to beta variant; S-delta= Spike antibodies to delta variant.
*Seropositive defined as S-antibodies to ancestral virus ≥ 1.09 WHO BAU/ml.
** Wave 2 n in mothers = 337 (2 excluded as vaccinated prior to wave 2 serum sample collection).
*** Wave 3 n in mothers = 244 (95 excluded as vaccinated prior to wave 3 serum sample collection).
**** Wave 4 n in mothers = 185 (154 excluded as vaccinated prior to wave 4 serum sample collection).
†42 mothers with Omicron results were seropositive in Wave 3 and seronegative in Wave 2.
††152 mothers with Omicron results were seropositive in Wave 3 and seropositive in Wave 2.
Note: Vaccinated mothers excluded; vaccination status is based on receiving at least 1 dose before or at 3 days prior to serum sample collection.
**2 mothers excluded as vaccinated before wave 2 blood sample collection.
***N for unvaccinated mothers with Omicron results= 194; N for vaccinated mothers with Omicron results=91.