White River Junction VA Medical Center, US Department of Veterans Affairs, White River Junction, Vermont, USA
White River Junction VA Medical Center, US Department of Veterans Affairs, White River Junction, Vermont, USA.
BMJ Open. 2022 Aug 3;12(8):e063935. doi: 10.1136/bmjopen-2022-063935.
To estimate the effectiveness of messenger RNA (mRNA) booster doses during the period of Delta and Omicron variant dominance.
We conducted a matched test-negative case-control study to estimate the vaccine effectiveness (VE) of three and two doses of mRNA vaccines against infection (regardless of symptoms) and against COVID-19-related hospitalisation and death.
Veterans Health Administration.
We used electronic health record data from 114 640 veterans who had a SARS-CoV-2 test during November 2021-January 2022. Patients were largely 65 years or older (52%), male (88%) and non-Hispanic white (59%).
First positive result for a SARS-CoV-2 PCR or antigen test.
Against infection, booster doses had higher estimated VE (64%, 95% CI 63 to 65) than two-dose vaccination (12%, 95% CI 10 to 15) during the Omicron period. For the Delta period, the VE against infection was 90% (95% CI 88 to 92) among boosted vaccinees, higher than the VE among two-dose vaccinees (54%, 95% CI 50 to 57). Against hospitalisation, booster dose VE was 89% (95% CI 88 to 91) during Omicron and 94% (95% CI 90 to 96) during Delta; two-dose VE was 63% (95% CI 58 to 67) during Omicron and 75% (95% CI 69 to 80) during Delta. Against death, the VE with a booster dose was 94% (95% CI 90 to 96) during Omicron and 96% (95% CI 87 to 99) during Delta.
Among an older, mostly male, population with comorbidities, we found that an mRNA vaccine booster was highly effective against infection, hospitalisation and death. Although the effectiveness of booster vaccination against infection was moderately higher against Delta than against the Omicron SARS-CoV-2 variant, effectiveness against severe disease and death was similarly high against both variants.
评估在德尔塔和奥密克戎变异株流行期间，信使 RNA（mRNA）加强针的效果。
我们开展了一项匹配的病例对照研究，以评估三剂和两剂 mRNA 疫苗对感染（无论症状）以及对 COVID-19 相关住院和死亡的疫苗有效性（VE）。
退伍军人健康管理局。
我们使用了 2021 年 11 月至 2022 年 1 月期间，114640 名接受 SARS-CoV-2 检测的退伍军人的电子健康记录数据。患者主要为 65 岁或以上（52%）、男性（88%）和非西班牙裔白人（59%）。
首次出现 SARS-CoV-2 PCR 或抗原检测阳性结果。
在奥密克戎流行期间，与两剂接种相比，加强针在预防感染方面具有更高的估计 VE（64%，95%CI63 至 65）。在德尔塔流行期间，加强针组预防感染的 VE 为 90%（95%CI88 至 92），高于两剂组的 VE（54%，95%CI50 至 57）。在预防住院方面，奥密克戎流行期间，加强针组 VE 为 89%（95%CI88 至 91），德尔塔流行期间 VE 为 94%（95%CI90 至 96）；奥密克戎流行期间，两剂组 VE 为 63%（95%CI58 至 67），德尔塔流行期间 VE 为 75%（95%CI69 至 80）。在预防死亡方面，奥密克戎流行期间，加强针组 VE 为 94%（95%CI90 至 96），德尔塔流行期间 VE 为 96%（95%CI87 至 99）。
在患有合并症的老年、男性为主的人群中，我们发现 mRNA 疫苗加强针在预防感染、住院和死亡方面非常有效。虽然加强针接种对感染的有效性在对抗德尔塔方面略高于对抗奥密克戎 SARS-CoV-2 变异株，但在预防严重疾病和死亡方面，对两种变异株的有效性同样高。
