Protection against the Omicron Variant from Previous SARS-CoV-2 Infection

Altarawneh, Heba N.; Chemaitelly, Hiam; Hasan, Mohammad R.; Ayoub, Houssein H.; Qassim, Suelen H.; AlMukdad, Sawsan; Coyle, Peter; Yassine, Hadi M.; Al-Khatib, Hebah A.; Benslimane, Fatiha; Al‐Kanaani, Zaina; Kuwari, Einas Al; Jeremijenko, Andrew; Kaleeckal, Anvar Hassan; Latif, Ali Nizar; Shaik, Riyazuddin Mohammad; Abdul-Rahim, Hanan F; Nasrallah, Gheyath K.; Al-Kuwari, Mohamed Ghaith; Butt, Adeel A.; Al-Romaihi, Hamad Eid; Al-Thani, Mohamed H.; Al‐Khal, Abdullatif; Bertollini, Roberto; Tang, Patrick; Abu‐Raddad, Laith J.

doi:10.1056/nejmc2200133

Cited by 386 publications

(380 citation statements)

References 5 publications

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“…The large exponential-growth phase of this wave of infections started on December 19, 2021, and reached its peak in mid-January 2022. 7 , 30…”

Section: Methodsmentioning

confidence: 99%

“…Waning of vaccine protection against coronavirus disease 2019 (Covid-19) 1-4 and the emergence of the immune-evasive omicron (or B.1.1.529) variant 5 of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), 6 , 7 which is a variant of concern, have stimulated efforts to scale up Covid-19 booster vaccination. Qatar launched its third-dose (booster) vaccination program in mid-September 2021.…”

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confidence: 99%

“…Our study population consisted of the national cohort of vaccinated persons in Qatar during the wave of infections with the omicron variant. 7 …”

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confidence: 99%

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Effect of mRNA Vaccine Boosters against SARS-CoV-2 Omicron Infection in Qatar

Abu‐Raddad

Chemaitelly

Ayoub³

et al. 2022

N Engl J Med

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332

368

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Background Waning of vaccine protection against coronavirus disease 2019 (Covid-19) and the emergence of the omicron (or B.1.1.529) variant of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have led to expedited efforts to scale up booster vaccination. Protection conferred by booster doses of the BNT162b2 (Pfizer–BioNTech) and mRNA-1273 (Moderna) vaccines in Qatar, as compared with protection conferred by the two-dose primary series, is unclear. Methods We conducted two matched retrospective cohort studies to assess the effectiveness of booster vaccination, as compared with that of a two-dose primary series alone, against symptomatic SARS-CoV-2 infection and Covid-19–related hospitalization and death during a large wave of omicron infections from December 19, 2021, through January 26, 2022. The association of booster status with infection was estimated with the use of Cox proportional-hazards regression models. Results In a population of 2,239,193 persons who had received at least two doses of BNT162b2 or mRNA-1273 vaccine, those who had also received a booster were matched with persons who had not received a booster. Among the BNT162b2-vaccinated persons, the cumulative incidence of symptomatic omicron infection was 2.4% (95% confidence interval [CI], 2.3 to 2.5) in the booster cohort and 4.5% (95% CI, 4.3 to 4.6) in the nonbooster cohort after 35 days of follow-up. Booster effectiveness against symptomatic omicron infection, as compared with that of the primary series, was 49.4% (95% CI, 47.1 to 51.6). Booster effectiveness against Covid-19–related hospitalization and death due to omicron infection, as compared with the primary series, was 76.5% (95% CI, 55.9 to 87.5). BNT162b2 booster effectiveness against symptomatic infection with the delta (or B.1.617.2) variant, as compared with the primary series, was 86.1% (95% CI, 67.3 to 94.1). Among the mRNA-1273–vaccinated persons, the cumulative incidence of symptomatic omicron infection was 1.0% (95% CI, 0.9 to 1.2) in the booster cohort and 1.9% (95% CI, 1.8 to 2.1) in the nonbooster cohort after 35 days; booster effectiveness against symptomatic omicron infection, as compared with the primary series, was 47.3% (95% CI, 40.7 to 53.3). Few severe Covid-19 cases were noted in the mRNA-1273–vaccinated cohorts. Conclusions The messenger RNA (mRNA) boosters were highly effective against symptomatic delta infection, but they were less effective against symptomatic omicron infection. However, with both variants, mRNA boosters led to strong protection against Covid-19–related hospitalization and death. (Funded by Weill Cornell Medicine–Qatar and others.)

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“…The large exponential-growth phase of this wave of infections started on December 19, 2021, and reached its peak in mid-January 2022. 7 , 30…”

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Effect of mRNA Vaccine Boosters against SARS-CoV-2 Omicron Infection in Qatar

Abu‐Raddad

Chemaitelly

Ayoub³

et al. 2022

N Engl J Med

Self Cite

332

368

View full text Add to dashboard Cite

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“…Qatar endured a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron (B.1.1.529) 1 wave that started on December 19, 2021 and peaked in mid-January, 2022 [2][3][4][5] . The wave was first dominated by the BA.1 Omicron subvariant, but within a few days, the BA.2 subvariant predominated (Figure 1).…”

Section: Introductionmentioning

confidence: 99%

Duration of mRNA vaccine protection against SARS-CoV-2 Omicron BA.1 and BA.2 subvariants in Qatar

Chemaitelly

Ayoub

AlMukdad

et al. 2022

Preprint

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The SARS-CoV-2 Omicron (B.1.1.529) variant has two subvariants, BA.1 and BA.2, that are genetically quite divergent. We conducted a matched, test-negative, case-control study to estimate duration of protection of mRNA COVID-19 vaccines, after the second dose and after a third/booster dose, against BA.1 and BA.2 infections in Qatar population. BNT162b2 effectiveness against symptomatic BA.1 infection was highest at 46.6% (95% CI: 33.4-57.2%) in the first three months after the second dose, but then declined to ~10% or below thereafter. Effectiveness rapidly rebounded to 59.9% (95% CI: 51.2-67.0%) in the first month after the booster dose, but then started to decline again. BNT162b2 effectiveness against symptomatic BA.2 infection was highest at 51.7% (95% CI: 43.2-58.9%) in the first three months after the second dose, but then declined to ~10% or below thereafter. Effectiveness rapidly rebounded to 43.7% (95% CI: 36.5-50.0%) in the first month after the booster dose, but then declined again. Effectiveness against COVID-19 hospitalization and death was in the range of 70-80% any time after the second dose, and was greater than 90% after the booster dose. Similar patterns of protection were observed for the mRNA-1273 vaccine. mRNA vaccines provide only moderate and short-lived protection against symptomatic Omicron infections, with no discernable differences in protection against either the BA.1 or BA.2 subvariants. Vaccine protection against COVID-19 hospitalization and death is strong and durable after the second dose, but is more robust after a booster dose.

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“…1,2 Emerging evidence suggests that omicron causes less severe disease than previous variants of concern (VOC), probably due to lower virulence, infection-acquired immunity, and higher vaccination coverage. [3][4][5][6] However, its high transmissibility and ability to partially evade the immune response induced has been associated with a substantial increase in severe Covid-19 cases globally. 2 The absolute number of pediatric hospital admissions has also surpassed previous waves, 4,7,8 straining healthcare systems even further.…”

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confidence: 99%

Effectiveness of CoronaVac in children 3 to 5 years during the omicron SARS-CoV-2 outbreak

Araos

Jara

Undurraga

et al. 2022

Preprint

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The outbreak of the B.1.1.529 lineage of SARS-CoV-2 (omicron) has caused an unprecedented number of Covid-19 cases, including pediatric hospital admissions. Policymakers urgently need evidence of vaccine effectiveness in children to balance the costs and benefits of vaccination campaigns, but the evidence is sparse or non-existing. Leveraging a population-based cohort of 490,694 children aged 3–5 years, we estimated the effectiveness of administering a two-dose schedule, 28 days apart, of CoronaVac using inverse probability-weighted survival regression models to estimate hazard ratios of complete immunization over non-vaccination, accounting for time-varying vaccination exposure and relevant confounders. The study was conducted between December 6, 2021, and February 26, 2022, during the omicron outbreak in Chile. The estimated vaccine effectiveness was 38.2% (95%CI, 36.5–39.9) against Covid-19, 64.6% (95%CI, 49.6–75.2) against hospitalization, and 69.0% (95%CI, 18.6–88.2) to prevent intensive care unit admission. The effectiveness was modest; however, protection against severe disease remained high.

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Protection against the Omicron Variant from Previous SARS-CoV-2 Infection

Cited by 386 publications

References 5 publications

Effect of mRNA Vaccine Boosters against SARS-CoV-2 Omicron Infection in Qatar

Effect of mRNA Vaccine Boosters against SARS-CoV-2 Omicron Infection in Qatar

Duration of mRNA vaccine protection against SARS-CoV-2 Omicron BA.1 and BA.2 subvariants in Qatar

Effectiveness of CoronaVac in children 3 to 5 years during the omicron SARS-CoV-2 outbreak

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