Safety and lower airway immunogenicity of two candidate Coronavirus Disease (COVID-19) vaccines administered to the respiratory tract

新冠肺炎疫苗要发挥最大效果，不仅要预防严重感染，还要限制病毒的脱落，这样才能阻断传播，控制大流行传播。流感疫苗Fluenz(以鼻腔喷雾的形式给予)的经验表明，鼻腔疫苗对这两种结果都有效。目前正在试验的所有新冠肺炎疫苗都是通过注射的方式提供的，但众所周知，直接刺激感染部位(即鼻子和肺部)的免疫会产生特殊的保护性反应，可能会更快、更彻底地控制感染。这项研究将测试英国两种主要的新冠肺炎疫苗，以表明它们是安全的，耐受性良好，当注射到呼吸道时，能够刺激血液和肺部的免疫反应。使用标准化方法，我们将直接比较这两种疫苗在血液、鼻子和下呼吸道的免疫反应，以及正在进行的肌肉接种临床试验的数据。因此，我们将展示不同疫苗技术和注射方法的效果，并提供开始进一步临床试验所需的关键信息，以显示这种无针接种策略的有效性。

For a COVID-19 vaccine to have maximum impact, it should not only prevent severe infection but also limit the shedding of virus so that transmission is interrupted and pandemic spread is controlled. Experience with the influenza vaccine FluEnz (which is given as a nasal spray) has shown that intranasal vaccines can be effective for both outcomes. All COVID-19 vaccines currently being trialled are delivered by injection but it is known that directly stimulating immunity at the site of infection (i.e. the nose and lung) induces specialised protective responses that may more quickly and completely control infection. This study will test the two leading UK COVID-19 vaccines to show that they are safe, well-tolerated and capable of stimulating immune responses both in the blood and the lung when administered to the respiratory tract. Using standardised methods, we will directly compare immune responses in the blood, nose and lower airway between these two vaccines as well as with data from ongoing clinical trials of intramuscular vaccination. Thus, we will show the effect of different vaccine technologies as well as delivery method and provide the critical information required to begin further clinical trials to show the efficacy of this needle-free vaccination strategy.