Long-term variations and potency of neutralizing antibodies against Omicron subvariants after CoronaVac-inactivated booster: A 7-month follow-up study.
J Med Virol
; : e28279, 2022 Nov 03.
Article
in English
| MEDLINE | ID: covidwho-2232491
ABSTRACT
The long-term protective efficacy of neutralizing antibodies (Nabs) against Omicron subvariants after inactivated booster vaccines remains elusive. During the follow-up study, 54 healthy volunteers aged 20-31 years received inactivated CoronaVac booster vaccinations and were monitored for 221 days. The dynamic efficacy and durability of Nab against Omicron subvariants BA.1, BA.2, BA.2.12.2, and BA4/5 were assessed using a pseudotyped virus neutralization assay at up to nine time points post immunization. The antibody response against Omicron subvariants was substantially weaker than D614G, with BA.4/5 being the least responsive. The geometric mean titer (GMT) of Nab against Omicron subvariants BA.1, BA.2, BA.2.12.1, and BA.4/5 was 2.2-, 1.7-, 1.8-, and 2.2-fold lower than that against D614G (ps < 0.0001). The gap in Nab response between Omicron subvariants was pronounced during the 2 weeks-2 months following booster vaccination (ps < 0.05). Seven months post booster, the antibody potency against D614G was maintained at 100% (50% for Nab titers ≥ 100 50% inhibitory dilution [EC50 ]), whereas at 77.3% for BA.1, 90.9% for BA.2, 86.4% for BA.2.12.1, and 86.4% for BA.4/5 (almost 20% for Nab titers ≥ 100 EC50 ). Despite the inevitable immune escape, Omicron subvariants maintained sustained and measurable antibody potency post-booster vaccination during long-term monitoring, which could help optimize immunization strategies.
Full text:
Available
Collection:
International databases
Database:
MEDLINE
Type of study:
Cohort study
/
Prognostic study
Topics:
Vaccines
/
Variants
Language:
English
Journal:
J Med Virol
Year:
2022
Document Type:
Article
Affiliation country:
Jmv.28279
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