key: cord-0688727-pobcu2be
authors: Zhu, Ka-Li; Gao, Hui-Xia; Yao, Lin; Rong, Jun; Yang, Li; Zhang, Zhi; Jiang, Ping; Duan, Li-Jun; Wang, Guo-Lin; Dai, Er-Hei; Ma, Mai-Juan
title: Delta infection following vaccination elicits potent neutralizing immunity against the SARS-CoV-2 Omicron
date: 2022-04-16
journal: J Infect Dis
DOI: 10.1093/infdis/jiac149
sha: abd03d7db5412aad19a417158dc82f26956a81ef
doc_id: 688727
cord_uid: pobcu2be

The SARS-CoV-2 Omicron (B.1.1.529) variant extensively escape neutralizing antibodies by vaccines or infection. We assessed serum neutralizing activity in sera from Delta infection following vaccination and Delta infection only against SARS-CoV-2 Wuhan-Hu-1 (WA1), Beta, Delta, and Omicron. Sera from Delta infection only could neutralize WA1 and Delta but nearly completely lost capacity to neutralize Beta and Omicron. However, Delta infection following vaccination resulted in a significant increase of serum neutralizing activity against WA1, Beta, and Omicron. This study demonstrates that breakthrough infection of Delta substantially induced high potency humoral immune response against the Omicron variant and other emerged variants.

Further analysis showed no significant differences in antibody response between patients that > 18 years old and 22 less than 18 years old regardless of WA1 and variants (Figure. (Figure. 1c) . Moreover, although GMT against the Omicron variant displayed a 4.3-fold and 5 14.5-fold decrease compared to GMT against the Delta and WA1, respectively, the serum had a high potency to 6 neutralize the Beta and Omicron variants. We observed that only one (3.2%) and five (16.1%) of 31 serum samples 7 completely lost neutralizing activity against the Beta and Omicron variants, respectively ( Figure. 1c) . We then 8 compared antibody response between patients vaccinated CoronaVac and ZF2001 ( Figure. 1d) . No significant 9 differences were observed for antibody response against WA1, Beta, and Omicron between the two groups, 10 whereas CoronaVac vaccinated patients displayed a higher GMT of 1949 against Beta than ZF2001 vaccinated 11 patients with a GMT of 960.4 ( Figure. 1d) . We further compared antibody response between patients with the 12 Delta infection alone and patients with the Delta infection following vaccination. We found that antibody levels 13 against WA1, Beta, and Omicron in serum from the Delta infection following vaccination were significantly higher 14 than the Delta infection alone (Figure. 1e) . In contrast, no significant difference was observed in the antibody titers 15 against the Delta between the two groups ( Figure. 

Antibody resistance of SARS-CoV-2 variants B.1.351 and B.1.1.7. 2

Effectiveness of the BNT162b2 Covid-19 Vaccine against the

B.1.1.7 and B.1.351 Variants

Efficacy of the ChAdOx1 nCoV-19 Covid-19 Vaccine against the

1.351 Variant

SARS-CoV-2 B.1.617.2 Delta variant replication and immune 8 evasion

Rapid epidemic expansion of the SARS-CoV-2 Omicron variant in 10 southern Africa

Considerable escape of SARS-CoV-2 Omicron to antibody 12 neutralization

mRNA-based COVID-19 vaccine boosters induce 14 neutralizing immunity against SARS-CoV-2 Omicron variant

BNT162b2 and mRNA-1273 COVID-19 vaccine effectiveness 16 against the SARS-CoV-2 Delta variant in Qatar

Neutralizing antibody levels are highly predictive of immune 18 protection from symptomatic SARS-CoV-2 infection

SARS-CoV-2 B.1.1.529 variant (Omicron) evades 20 neutralization by sera from vaccinated and convalescent individuals

SARS-CoV-2 vaccination induces immunological T cell memory 23 able to cross-recognize variants from Alpha to Omicron

Adaptive immunity to SARS-CoV-2 and COVID-19

mRNA booster immunization elicits potent neutralizing 26 serum activity against the SARS-CoV-2 Omicron variant

SARS-CoV-2 mRNA vaccines induce persistent human 28 germinal centre responses

mRNA vaccination boosts cross-variant neutralizing