TABLE. Neutralization and anti-spike antibody titers in nursing home residents after previous receipt of 1 or 2 monovalent mRNA COVID-19 vaccine booster doses and before and after receipt of a bivalent booster dose — Ohio and Rhode Island, September–November 2022.
| Assay |
Virus strain |
No. of MV booster doses received | GMT (95% CI)* |
Adjusted p-value† |
||||
|---|---|---|---|---|---|---|---|---|
| After receipt of BV dose |
After last MV dose versus before BV dose | |||||||
| After last MV§ booster dose | Before BV booster dose | After BV booster dose | Versus after last MV dose | Versus before BV dose | ||||
| Neut |
BA.1 |
1 |
153 (87–272) |
25 (15–43) |
1,205 (675–2,149) |
<0.001 |
<0.001 |
<0.001 |
| Neut |
BA.1 |
2 |
924 (621–1,373) |
204 (109–384) |
1,506 (1,000–2,269) |
0.022 |
<0.001 |
<0.001 |
| Neut |
BA.4/5 |
1 |
186 (61–567) |
31 (20–49) |
1,425 (799–2,539) |
0.035 |
<0.001 |
0.105 |
| Neut |
BA.4/5 |
2 |
1,055 (589–1,614) |
160 (84–307) |
1,964 (1,356–2,842) |
0.001 |
<0.001 |
<0.001 |
| Neut |
Wu |
1 |
848 (574–1,253) |
78 (51–121) |
2,608 (1,700–3,999) |
0.011 |
<0.001 |
<0.001 |
| Neut |
Wu |
2 |
1,333 (931–1,908) |
445 (256–771) |
2,594 (1,874–3,589) |
<0.001 |
<0.001 |
<0.001 |
| Spike |
BA.1 |
1 |
2,090 (983–4,444) |
56 (37–85) |
780 (578–1,053) |
0.034 |
<0.001 |
<0.001 |
| Spike |
BA.1 |
2 |
1,393 (1,118–1,735) |
258 (176–379) |
887 (747–1,053) |
0.021 |
<0.001 |
<0.001 |
| Spike |
BA.4/5 |
1 |
270 (144–506) |
45 (32–61) |
960 (726–1,269) |
0.062 |
<0.001 |
<0.001 |
| Spike |
BA.4/5 |
2 |
1,014 (840–1,239) |
235 (158–351) |
993 (837–1,179) |
1.0 |
<0.001 |
<0.001 |
| Spike |
Wu |
1 |
3,554 (2,216–5,699) |
126 (82–194) |
2,445 (1,755–3,407) |
1.0 |
<0.001 |
<0.001 |
| Spike | Wu | 2 | 3,786 (3,009–4,765) | 816 (504–1,320) | 2,725 (2,221–3,343) | 0.833 | <0.001 | <0.001 |
Abbreviations: BV = bivalent; GMT = geometric mean titer; MV = monovalent; Neut = neutralization; Wu = Wuhan.
* Values are geometric mean of titer and 95% CI.
† P-values method: predicted log-transformed using linear mixed-effects model, repeated measures within subject grouped using random subject effect. Estimated time contrasts from these models compared and p-values presented. Given three contrasts over 12 models, added a Bonferroni adjustment for the 36 tests present in table.
§ Timepoints: testing after receipt of the MV and BV booster dose a median of 17 days. In the group that received 1 monovalent booster dose, testing before bivalent dose occurred 11 months after receipt of the first booster dose and a median of 48 days before receipt of the bivalent booster dose. In the group that received 2 MV booster doses, testing before the BV dose occurred 3 months after receipt of the second booster dose and a median of 49 days before administration of the BV booster.