Studies confirm enhanced protection from Omicron-related hospitalizations with COVID boosters

In a recent article posted on medRxiv* Preprint server, evaluation by scientists Effectiveness of Primary and additional therapy for SARS-CoV-2 omicron-related hospitalization in the United States (US) with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination.

..study: Vaccine efficacy of primary series and booster immunization for Omicron mutant COVID-19-related hospitalization in the United States.. Image Credit: Skylines / Shutterstock

Background

The highly contagious SARS-CoV-2 omicron variant, first discovered in South Africa in November 2021, became the predominant viral variant in the United States at the end of December 2021. The new BA.1 and BA.2 strains are the largest ever encountered in the United States, peaking at over 400,000 patients per day.

Increasing evidence for coronavirus disease 2019 (COVID-19) vaccine protection against Omicron infection is ambiguous. In addition, there is uncertainty about the effectiveness of the SARS-CoV-2 vaccine booster dose and whether the COVID-19 booster dose is most useful for certain demographic and risk groups. In addition, it is difficult to determine the efficacy of COVID-19 vaccination against serious illnesses caused by the Omicron variant and its strains, which may explain a wide range of recent results.

About research

In the current study, researchers found that primary SARS-CoV-2 vaccine therapy and booster immunotherapy alone were effective in preventing COVID-19 hospitalization associated with the SARS-CoV-2 omicron variant. I compared. The team used a test-negative strategy to examine vaccine efficacy (VE) in current multicenter case-control studies at 21 hospitals across the United States.

The authors sought to clarify the efficacy of COVID-19 vaccine booster doses and the interaction of antigenic escape and immunosuppression in omicron surges. In addition, they evaluated serum antibody titers in healthy adult participants and evaluated the anti-SARS-CoV-2 response before and after receiving booster immunization as a laboratory study to complement these clinical VE studies.

This study consisted of 3,181 adults hospitalized for acute respiratory illness between December 26, 2021 and April 30, 2022, with SARS-CoV-2 Omicron BA.1 and BA.2 variants. Was dominant. Laboratory-verified cases of SARS-CoV-2 infection were 1,572, or 49%, and COVID-19-negative controls were 1,609, or 51%.

VE for SARS-CoV-2 related hospitalizations, a key outcome indicator, is only by comparing the likelihood of being vaccinated in each series compared to unvaccinated, additional vaccination and subsequent vaccination. Estimated for the initial vaccination regimen. Between case and control. VE analysis was isolated based on immune status. That is, whether they are immune or immunocompromised because the recommended vaccination schedules for these populations are different. A core analysis evaluated all COVID-19 vaccine types to be integrated, while a supplemental study evaluated individual vaccine products.

Weekly admission SARS-CoV-2 Omicron strains of 1,572 COVID-19 patients enrolled between December 26, 2021 and April 30, 2022 (January 25-31, 2022) Registration is suspended). The sequenced Omicron variants are BA.1 (B.1.1.529, BA.1, BA.1.1, BA.1.15, BA.1.17) and BA.2 (BA.2, BA.2.1, BA.2.3). Grouped into strains. .. Non-Omicron case patients (delta variant, B.1.1.519) identified by sequencing were excluded from the analysis (n = 64) and are not shown in this figure. Of the 444 patients with Omicron variant infection whose sequence was confirmed, 396 (89%) had BA.1 and 48 (11%) had BA.2. The low total sequence in late January reflects the suspension of IVY network registration between January 25-31, 2022, during the protocol update.

result

The study results showed that the median age of study volunteers was 64 years, 21% were immunodeficient, and 48% were female. In addition, 798, or 25%, were immunized with the primary COVID-19 vaccination series and booster immunization. 1,326, or 42%, were vaccinated with the primary vaccination regimen only. 1,057, or 33%, were unvaccinated.

VE for immunization personnel’s Omicron-related COVID-19 hospitalization was 77% for first-line vaccine therapy combined with a single booster dose of any vaccine product and 44% for the first-line series alone. The VE of COVID-19 hospitalization for the primary series of vaccine formulations and Omicron-related was 60% in immunocompromised patients. Inadequate sample size hampered the estimation of the effectiveness of boosted schedules among immunocompromised participants.

The additional vaccination schedule for the two messenger ribonucleic acid (mRNA) vaccines administered in the United States had a higher VE than the primary regimen alone. The VE for the primary series and booster doses of the SARS-CoV-2 BNT162b2 vaccine was 80%, while the VE for the primary series alone was 46%. In addition, the primary series and booster VE of the COVID-19 mRNA-1273 vaccine was 77%, while the VE of the primary series alone was 47%.

In addition, the SARS-CoV-2 mRNA vaccines (mRNA-1273 and BNT162b2) showed better protection than the Ad26.COV2 vaccine in both booster therapy and the primary series alone. In addition, serological data showed significantly higher anti-SARS-CoV-2 antibody levels after booster immunization, confirming clinical VE results.

Overall, the findings suggested that receiving COVID-19 primary vaccine therapy and booster immunization provided better protection from COVID-19-related hospitalization than receiving the primary vaccine course alone. This increase in immunity with booster vaccine doses was observed in all age categories and in all three vaccine formulations adopted in the United States.

Conclusion

Research results show that booster doses of the SARS-CoV-2 vaccine provide additional benefits over primary vaccine series alone in reducing omicron-related hospitalizations in the US population. In addition, the SARS-CoV-2 mRNA vaccine outperformed the Ad26.COV2 vaccine in both booster immunotherapy and the primary series. Serological results confirm a significant increase in anti-SARS-CoV-2 antibody levels, especially after booster vaccine administration with the mRNA vaccine.

In summary, current findings support the advice that all eligible people over the age of 18 in the United States receive mRNA vaccine booster doses to protect them from the serious illness of the Omicron mutant.

*Important Notices

medRxiv Publish preliminary scientific reports that should not be considered definitive as they have not been peer-reviewed, guide clinical practice / health-related behaviors, and should not be treated as established information.