小柯机器人

英国牛津大学Andrew J Pollard团队研究了ChAdOx1 nCoV-19疫苗抗SARS-CoV-2感染的安全性和有效性。2020年12月8日，该研究发表在《柳叶刀》杂志上。

若存在一种针对SARS-CoV-2的安全有效疫苗，且广泛接种，则有助于控制COVID-19大流行。研究组在四项试验的汇总中期分析中评估了ChAdOx1 nCoV-19疫苗的安全性和有效性。

研究组在英国、巴西和南非进行了四项双盲的随机对照试验， 招募18岁及以上的参与者，将其按1：1随机分配，分别接种ChAdOx1 nCoV-19疫苗或对照疫苗（脑膜炎球菌A、C、W和Y结合疫苗或生理盐水）。主要观察指标为第二次疫苗接种后14天以上血清阴性、核酸检测阳性的有症状的Covid-19。

2020年4月23日至11月4日，共有23848名参与者入组，其中11636名参与者（英国7548名，巴西4088名）被纳入中期主要疗效分析。在接种了两剂标准剂量疫苗的参与者中，疫苗效力为62.1%；在先接种低剂量、后接种标准剂量的参与者中，疫苗效力为90.0%。两组的总体疫苗效力为70.4％。

在初次接种后的21天，对照组中有10例参与者因COVID-19住院，其中2例为重症COVID-19，1例最终死亡。安全随访74341人-月后，共有168名参与者发生了175次严重不良事件，其中ChAdOx1 nCoV-19组发生了84次事件，而对照组发生了91次。有三次事件被归类为可能与疫苗有关，其中ChAdOx1 nCoV-19组一件，对照组一件，未分组的参与者中一件。

该试验中期分析表明，ChAdOx1 nCoV-19安全耐受，可有效预防COVID-19。

附：英文原文

Title: Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK

Author: Merryn Voysey, Sue Ann Costa Clemens, Shabir A Madhi, Lily Y Weckx, Pedro M Folegatti, Parvinder K Aley, Brian Angus, Vicky L Baillie, Shaun L Barnabas, Qasim E Bhorat, Sagida Bibi, Carmen Briner, Paola Cicconi, Andrea M Collins, Rachel Colin-Jones, Clare L Cutland, Thomas C Darton, Keertan Dheda, Christopher J A Duncan, Katherine R W Emary, Katie J Ewer, Lee Fairlie, Saul N Faust, Shuo Feng, Daniela M Ferreira, Adam Finn, Anna L Goodman, Catherine M Green, Christopher A Green, Paul T Heath, Catherine Hill, Helen Hill, Ian Hirsch, Susanne H C Hodgson, Alane Izu, Susan Jackson, Daniel Jenkin, Carina C D Joe, Simon Kerridge, Anthonet Koen, Gaurav Kwatra, Rajeka Lazarus, Alison M Lawrie, Alice Lelliott, Vincenzo Libri, Patrick J Lillie, Raburn Mallory, Ana V A Mendes, Eveline P Milan, Angela M Minassian, Alastair McGregor, Hazel Morrison, Yama F Mujadidi, Anusha Nana, Peter J O’Reilly, Sherman D Padayachee, Ana Pittella, Emma Plested, Katrina M Pollock, Maheshi N Ramasamy, Sarah Rhead, Alexandre V Schwarzbold, Nisha Singh, Andrew Smith, Rinn Song, Matthew D Snape, Eduardo Sprinz, Rebecca K Sutherland, Richard Tarrant, Emma C Thomson, M Estée Trk

Issue&Volume: 2020-12-08

Abstract:

Background

A safe and efficacious vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), if deployed with high coverage, could contribute to the control of the COVID-19 pandemic. We evaluated the safety and efficacy of the ChAdOx1 nCoV-19 vaccine in a pooled interim analysis of four trials.

Methods

This analysis includes data from four ongoing blinded, randomised, controlled trials done across the UK, Brazil, and South Africa. Participants aged 18 years and older were randomly assigned (1:1) to ChAdOx1 nCoV-19 vaccine or control (meningococcal group A, C, W, and Y conjugate vaccine or saline). Participants in the ChAdOx1 nCoV-19 group received two doses containing 5×1010 viral particles (standard dose; SD/SD cohort); a subset in the UK trial received a half dose as their first dose (low dose) and a standard dose as their second dose (LD/SD cohort). The primary efficacy analysis included symptomatic COVID-19 in seronegative participants with a nucleic acid amplification test-positive swab more than 14 days after a second dose of vaccine. Participants were analysed according to treatment received, with data cutoff on Nov 4, 2020. Vaccine efficacy was calculated as 1-relative risk derived from a robust Poisson regression model adjusted for age. Studies are registered at ISRCTN89951424 and ClinicalTrials.gov, NCT04324606, NCT04400838, and NCT04444674.

Findings

Between April 23 and Nov 4, 2020, 23848 participants were enrolled and 11636 participants (7548 in the UK, 4088 in Brazil) were included in the interim primary efficacy analysis. In participants who received two standard doses, vaccine efficacy was 62·1% (95% CI 41·0–75·7; 27 [0·6%] of 4440 in the ChAdOx1 nCoV-19 group vs71 [1·6%] of 4455 in the control group) and in participants who received a low dose followed by a standard dose, efficacy was 90·0% (67·4–97·0; three [0·2%] of 1367 vs 30 [2·2%] of 1374; pinteraction=0·010). Overall vaccine efficacy across both groups was 70·4% (95·8% CI 54·8–80·6; 30 [0·5%] of 5807 vs 101 [1·7%] of 5829). From 21 days after the first dose, there were ten cases hospitalised for COVID-19, all in the control arm; two were classified as severe COVID-19, including one death. There were 74341 person-months of safety follow-up (median 3·4 months, IQR 1·3–4·8): 175 severe adverse events occurred in 168 participants, 84 events in the ChAdOx1 nCoV-19 group and 91 in the control group. Three events were classified as possibly related to a vaccine: one in the ChAdOx1 nCoV-19 group, one in the control group, and one in a participant who remains masked to group allocation.

Interpretation

ChAdOx1 nCoV-19 has an acceptable safety profile and has been found to be efficacious against symptomatic COVID-19 in this interim analysis of ongoing clinical trials.

DOI: 10.1016/S0140-6736(20)32661-1

Source: https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)32661-1/fulltext

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