Effects of Previous Infection and Vaccination on Symptomatic Omicron Infections

New England Journal of Medicine, Journal Year: 2022, Volume and Issue: 387(1), P. 21 - 34

Published: June 15, 2022

The protection conferred by natural immunity, vaccination, and both against symptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection with the BA.1 or BA.2 sublineages of omicron (B.1.1.529) variant is unclear.

Language: Английский

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

Nature Communications, Journal Year: 2022, Volume and Issue: 13(1)

Published: June 2, 2022

Abstract SARS-CoV-2 Omicron BA.1 and BA.2 subvariants are genetically divergent. We conducted a matched, test-negative, case-control study to estimate duration of protection the second third/booster doses mRNA COVID-19 vaccines against infections in Qatar. BNT162b2 effectiveness was highest at 46.6% (95% CI: 33.4–57.2%) symptomatic 51.7% 43.2–58.9%) first three months after dose, but declined ~10% or below thereafter. Effectiveness rebounded 59.9% 51.2–67.0%) 43.7% 36.5–50.0%), respectively, month booster before declining again. hospitalization death 70–80% dose >90% dose. mRNA-1273 vaccine showed similar patterns. provide comparable, moderate, short-lived infections, strong durable death.

Language: Английский

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Proportion of asymptomatic infection and nonsevere disease caused by SARS‐CoV‐2 Omicron variant: A systematic review and analysis

Journal of Medical Virology, Journal Year: 2022, Volume and Issue: 94(12), P. 5790 - 5801

Published: Aug. 13, 2022

SARS-CoV-2 Omicron variant seemed to cause milder disease compared previous predominated variants. We aimed conduct a meta-analysis assess the pooled proportion of nonsevere and asymptomatic infection among COVID-19 patients infected with Delta. searched PubMed, Embase, Web Science, China National Knowledge Infrastructure (CNKI) databases. included studies from November 1, 2021, April 18, 2022, Delta October 2020, June 30, 2022. Studies without corresponding data, less than 50 patients, or obviously biased concerning main outcome were excluded. Meta-analysis was performed in R 4.2.0 "meta" package. Subgroup analyses conducted by study group vaccination status. The 25.5% (95% confidence interval [CI] 17.0%-38.2%) 97.9% CI 97.1%-98.7%), significantly higher those 8.4% 4.4%-16.2%) 91.4% 87.0%-96.0%). During wave, children adolescents had infection, SOTR elderly lower disease, booster dose contributed both disease. This estimates caused other predominant result has important implications for future policy making.

Language: Английский

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Short term, relative effectiveness of four doses versus three doses of BNT162b2 vaccine in people aged 60 years and older in Israel: retrospective, test negative, case-control study

BMJ, Journal Year: 2022, Volume and Issue: unknown, P. e071113 - e071113

Published: May 24, 2022

To examine the relative effectiveness of a fourth dose Pfizer-BioNTech mRNA (BNT162b2) vaccine compared with three doses over span 10 weeks. Retrospective, test negative, case-control study, matched analysis and an unmatched multiple tests analysis. Nationally centralised database Maccabi Healthcare Services, Israeli national health fund for 2.5 million people; from January 2022 (seven days after was first given to eligible individuals) 13 March 2022, omicron dominant period in Israel. 97 499 Services members aged 60 years older, who were receive obtained at least one polymerase chain reaction (PCR) during study. Breakthrough SARS-CoV-2 infection, defined as positive PCR performed seven or more inoculation BNT162b2 vaccine; breakthrough infection resulting severe covid-19 disease, hospital admission death related covid-19. 27 876 participants received 69 623 only. Of 106 died follow-up period, 77 had their third only 23 weeks inoculation. In weeks, provided additional protection against both disease vaccine. However, quickly decreased time, peaking week 65.1% (95% confidence interval 63.0% 67.1%) falling 22.0% (4.9% 36.1%) by end period. Unlike maintained high level (>72%) throughout follow-up. relatively rare event, occurring <1% study four A appears have doses. wane sooner than that dose.

Language: Английский

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Evaluation of BNT162b2 Covid-19 Vaccine in Children Younger than 5 Years of Age

New England Journal of Medicine, Journal Year: 2023, Volume and Issue: 388(7), P. 621 - 634

Published: Feb. 15, 2023

Safe and effective vaccines against coronavirus disease 2019 (Covid-19) are urgently needed in young children. We conducted a phase 1 dose-finding study conducting an ongoing 2-3 safety, immunogenicity, efficacy trial of the BNT162b2 vaccine healthy children 6 months to 11 years age. present results for less than 2 age those 4 through data-cutoff dates (April 29, 2022, safety immunogenicity June 17, efficacy). In trial, participants were randomly assigned (in 2:1 ratio) receive two 3-μg doses or placebo. On basis preliminary results, third dose (≥8 weeks after 2) was administered starting January which coincided with emergence B.1.1.529 (omicron) variant. Immune responses at month 3 immunologically bridged persons 16 25 who received 30 μg pivotal trial. During study, 21 days apart (3-μg dose) 48 10-μg dose). The level selected trial; 1178 1835 BNT162b2, 598 915, respectively, Immunobridging success criteria geometric mean ratio seroresponse met both groups. reactogenicity events mostly mild moderate, no grade events. Low, similar incidences fever reported receipt (7% among <2 5% age) placebo (6 7% age). observed overall symptomatic Covid-19 73.2% (95% confidence interval, 43.8 87.6) from 7 (on 34 cases). A three-dose primary series safe, immunogenic, efficacious (Funded by BioNTech Pfizer; ClinicalTrials.gov number, NCT04816643.).

Language: Английский

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Severity of the Omicron SARS‐CoV‐2 variant compared with the previous lineages: A systematic review

Journal of Cellular and Molecular Medicine, Journal Year: 2023, Volume and Issue: 27(11), P. 1443 - 1464

Published: May 18, 2023

The Omicron variant was first detected in October 2021, which evolved from the original SARS-CoV-2 strain and found to possess many mutations. Immune evasion one of notable consequences these Despite exhibiting increased transmissibility, rates hospitalizations deaths among patients infected with this were substantially lower when compared other strains. However, concluding that is less severe than variants requires consideration multiple factors, including vaccination status as well any previous infections variants. This review compiled data about reported indicators severity Omicron-infected patients, studies comparing while adjusting for confounders. A comprehensive search conducted using different databases target Omicron. In total, 62 met our inclusion criteria included study. Many a significantly reduced risk hospitalization, ICU admission, need oxygenation/ventilation, death variants, such Delta. Some studies, however, comparable emphasizing substantial illness. Furthermore, COVID-19 vaccines effective against relative lineages, except after receiving booster dose. One study recommended during pregnancy, may help prevent future cases pneumonia neonates young infants due transfer humoral response mother.

Language: Английский

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Analysis of COVID-19 Incidence and Severity Among Adults Vaccinated With 2-Dose mRNA COVID-19 or Inactivated SARS-CoV-2 Vaccines With and Without Boosters in Singapore

JAMA Network Open, Journal Year: 2022, Volume and Issue: 5(8), P. e2228900 - e2228900

Published: Aug. 26, 2022

Assessing booster effectiveness of COVID-19 mRNA vaccine and inactivated SARS-CoV-2 over longer time intervals in response to any further variants is crucial determining optimal vaccination strategies.To determine levels protection against severe confirmed infection by types combinations boosters Singapore during the Omicron wave.This cohort study included residents aged 30 years or more vaccinated with either at least 2 doses vaccines (ie, Pfizer-BioNTech BNT162b2 Moderna mRNA-1273) (Sinovac CoronaVac Sinopharm BBIBP-CorV) as March 10, 2022. Individuals a known prior December 27, 2021, an on before date their second dose, reinfection cases were excluded.Two 3 BNT162b2, mRNA-1273, Sinovac CoronaVac, BBIBP-CorV.Notified infections from 2022, adjusted for age, sex, race, housing status, calendar days. Estimated effectiveness, defined relative incidence-rate reduction disease (supplemental oxygen, intensive care, death) following 3-dose compared 5 months after was determined using binomial regression.Among 441 581 eligible individuals (1 279 047 [52.4%] women, 846 110 (34.7%) 60 older), there 319 943 (13.1%) infections, which 1513 (0.4%) cases. 15 days boosting estimated range 31.7% 41.3% 4 (homologous homologous 2-dose BNT162b2/mRNA-1273 booster, mRNA-1273/BNT162b2 booster). Five boosting, waned, ranging -2.8% 14.6%. Against COVID-19, 87.4% (95% CI, 83.3%-90.5%) 87.2% 84.2%-89.7%) 6 no significant difference comparing combinations. Booster 330 vaccination, regardless combination, be 69.6% 48.7%-81.9%).Booster durable months. Three-dose provided greater than but weaker mRNA.

Language: Английский

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Expert review of global real-world data on COVID-19 vaccine booster effectiveness and safety during the omicron-dominant phase of the pandemic

Expert Review of Vaccines, Journal Year: 2022, Volume and Issue: 22(1), P. 1 - 16

Published: Nov. 4, 2022

COVID-19 vaccines have been highly effective in reducing morbidity and mortality during the pandemic. However, emergence of Omicron variant subvariants as globally dominant strains raised doubts about effectiveness currently available prompted debate potential future vaccination strategies.Using publicly IVAC VIEW-hub platform, we reviewed 52 studies on vaccine (VE) after booster vaccinations. VE were reported for SARS-CoV-2 symptomatic infection, severe disease death stratified by schedule age. In addition, a non-systematic literature review safety was performed to identify single or multi-country investigating adverse event rates at least two vaccines.Booster shots current provide consistently high protection against Omicron-related death. Additionally, this appears be conserved 3 months, with small but significant waning that. The positive risk-benefit ratio these is well established, giving us confidence administer additional doses required. Future strategies will likely include combination schedules based risk profile, overly frequent boosting may neither beneficial nor sustainable general population.

Language: Английский

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Effect of prior infection, vaccination, and hybrid immunity against symptomatic BA.1 and BA.2 Omicron infections and severe COVID-19 in Qatar

medRxiv (Cold Spring Harbor Laboratory), Journal Year: 2022, Volume and Issue: unknown

Published: March 22, 2022

BACKGROUND: Protection offered by five different forms of immunity, combining natural and vaccine was investigated against SARS-CoV-2 Omicron symptomatic BA.1 infection, BA.2 hospitalization death, in Qatar, between December 23, 2021 February 21, 2022. METHODS: Six national, matched, test-negative case-control studies were conducted to estimate effectiveness BNT162b2 (Pfizer-BioNTech) vaccine, mRNA-1273 (Moderna) immunity due prior infection with pre-Omicron variants, hybrid from vaccination. RESULTS: Effectiveness only 46.1% (95% CI: 39.5-51.9%). two-dose vaccination negligible at -1.1% -7.1-4.6), but nearly all individuals had received their second dose several months earlier. three-dose 52.2% 48.1-55.9%). 55.1% 50.9-58.9%). 77.3% 72.4-81.4%). Meanwhile, vaccination, showed strong >70% any severe, critical, or fatal COVID-19 infection. Similar levels patterns observed for the vaccine. CONCLUSIONS: There are no discernable differences effects versus BA.2. Hybrid resulting recent booster confers strongest protection either subvariant. Vaccination enhances those a

Language: Английский

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Effectiveness of the pre-Omicron COVID-19 vaccines against Omicron in reducing infection, hospitalization, severity, and mortality compared to Delta and other variants: A systematic review

Human Vaccines & Immunotherapeutics, Journal Year: 2023, Volume and Issue: 19(1)

Published: Jan. 2, 2023

Despite widespread mass rollout programs, the rapid spread of SARS-CoV-2 Omicron variant called into question effectiveness existing vaccines against infection, hospitalization, severity, and mortality compared to previous variants. This systematic review summarizes compares COVID-19 vaccines, with respect above outcomes in adults, children, adolescents. A comprehensive literature search was undertaken on several databases. Only 51 studies met our inclusion criteria, revealing that protection from primary vaccination infection is inferior Delta Alpha infections wanes faster over time. However, mRNA vaccine boosters were reported reestablish effectiveness, although a lower extent Omicron. Nonetheless, shown preserve strong Omicron-associated death, even months after last dose. provide more robust longer-lasting hospitalizations due as only series.

Language: Английский

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