CINXE.COM

<!DOCTYPE html><html lang="en-US"><head><title>Just a moment...</title><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=Edge"><meta name="robots" content="noindex,nofollow"><meta name="viewport" content="width=device-width,initial-scale=1"><style>*{box-sizing:border-box;margin:0;padding:0}html{line-height:1.15;-webkit-text-size-adjust:100%;color:#313131;font-family:system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,Noto Sans,sans-serif,Apple Color Emoji,Segoe UI Emoji,Segoe UI Symbol,Noto Color Emoji}body{display:flex;flex-direction:column;height:100vh;min-height:100vh}.main-content{margin:8rem auto;max-width:60rem;padding-left:1.5rem}@media (width <= 720px){.main-content{margin-top:4rem}}.h2{font-size:1.5rem;font-weight:500;line-height:2.25rem}@media (width <= 720px){.h2{font-size:1.25rem;line-height:1.5rem}}#challenge-error-text{background-image:url(data:image/svg+xml;base64,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);background-repeat:no-repeat;background-size:contain;padding-left:34px}@media (prefers-color-scheme:dark){body{background-color:#222;color:#d9d9d9}}</style><meta http-equiv="refresh" content="120"></head><body class="no-js"><div class="main-wrapper" role="main"><div class="main-content"><noscript><div class="h2"><span id="challenge-error-text">Enable JavaScript and cookies to continue</span></div></noscript></div></div><script>(function(){window._cf_chl_opt={cvId: '3',cZone: "publications.waset.org",cType: 'non-interactive',cRay: '913421785b071a58',cH: 'IjW7dwNRj0q5aJGW4qGq4NWl0t1rVpROA7_Lghh_JpY-1739778041-1.2.1.1-9D5lnpz_0AvH4Tz857k5s7Nhz0etsjXGuNhg42CZoBoq97cMpp6UOkiPDkNJMG7g',cUPMDTk: "\/abstracts\/search?q=COVID-19&__cf_chl_tk=y.Ht60eF6zvD7aDvC72aKzGGxAShEYCUZKxa1K6vrS8-1739778041-1.0.1.1-8QprQ_LmtpXxRYRvvRTxfZJbPPArSmc1pwwGqEilloc",cFPWv: 'b',cITimeS: '1739778041',cTTimeMs: '1000',cMTimeMs: '120000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/abstracts\/search?q=COVID-19&__cf_chl_f_tk=y.Ht60eF6zvD7aDvC72aKzGGxAShEYCUZKxa1K6vrS8-1739778041-1.0.1.1-8QprQ_LmtpXxRYRvvRTxfZJbPPArSmc1pwwGqEilloc",md: "Q3KfM45byy.BzCrE51LmwHX1QMGRyeueiSse46Rc0vA-1739778041-1.2.1.1-yAFMz1fb.iTkmRRijH8bJ8LxoWy.cNXHnb5cJzikbRkzKT33IJ3Y03FJjn8P25BVtx2eZ9mO4kpEhbpxloY_Ci45EEoVzTkpih.MgzvgjajUSaOg_KE_k9VnhyP1uKBXDHy8g8wOOKzDhgiVMophWwjjWYQFannYYogkZ8zGBLbzZTeA7raypZkgDumv5.LtbYjCTCafP6wpTlFd5VHIzj90rcxAMSozy1zy0VJHiChaSHvnIrAgo9IdlvxUG40LS6OGns7Km7PLASJhXiadYCqcWW8u67wF4IcesOC.MNwFNGRmDmC56mdRbTdk6t1lyqD9JvJ2hN.ARCEljZlYWdVoEtVVsk47M_l25SJirgeRu.Y6qCEpvLktS_8bmK.9F0loS.CtOsgdFi8.mQxIeQlzFfqHpP0NexXGxrkhJcIveirXTp7g89w3R10FK0RKkDxoPK3gh9a5hVkA9BadwvY60pqc05d7B2mtVsEpAE4TlSzJhspOLzajZgtPY9SEllAMlwxb0V.kKtfB_jezKD.dhONLtMa5aeuFN.V_PmsThmpfoG5GeB0L1B89xJ8tIR5hgmNL8a9bQ1pPzP.gcT92JLSALG32ohoYCjcbjryW_.2qiQkEqMhZAu31gqfPtp77IraOsGIDxlWrUds78KShqSsmP_kBn0BooIXYpfZyLeXNh9jsEHnSk7IU4Ct4ZK4PP4e1PwWj5t0xv1rNJJGFgqKcZ6h7.cT9NYCbs.wYxvM_DJS2H9ja7Zrx0R7ZM_nFyYbrH7EnA6JD8fbWfg5qW3xYxLZaCNnyiVaVqZErpUg6spceJhI3t8amZsoIzKdRNbg4AWwS0EFIBDVIE443nkLpeYw.hf5DHIXI3bK5I19sG0Ci902RmuyP9unbXeQg5ETlyn.nnKigZNh2eX4859UEj_m96qN7KS9O95DUoalO_spRQhHwCO9y0__bJ3G7Hk.YVW.j1OxBJ2lo5TEbhzaGRwoiGsqLQdrN7FJ_SIAWi02gwVO6XhlNerUuMzD1Wct2J8WmfIvJFxS0YjAR.nUYWAldmwEMl.PehfbALVqx7Aa0ivwvoECmB5mimwCITYzZuGdKjF5jQB.iHmXPnKwLrogJPrVAxQc3llHzbMIxGFh3zaEeDrHK2Gz_y5LCM9HFdpX4IZ4uB1I8UALv_uFvRweg0sIUtEq0QY1v3qSBx11S0GrDgtTprPRePkvTWrWlGB8i3w7z0.GsDPfJ7trPrLf9uiwVoCxyOPLS3HGAIBSucXvdCUL.RLDir4uEQNI1NZtX837sA8BG9pNr7LLhO.XiLP46aYgqYgJqN3NnhZocgppXnU5C9pnAfxXILFLMHoKPncRFIqTyG83PzwWHYckN_OfcdV8ocGUJAMBLrHEdEkEfBum14tUYqat.qfXTcgMAJ_eSpB6usIxV27jeOEo.xzCWjXu6YCDbllN4aBu7v5IF7S9bKa1_06lA3T0vzfdLPjEku254oCZz1VJmT0jy5cAp48CwAuopCQ1cPJXS2Ht6z8Fnv3PxiyBFdEUd_cZzU.sDa0Ds7ZYpL3LK7jmzz5RHu19l1tayqlU8_71wT7Gd1qZt66XLuaLuG0eK.8qxtZ0POniB8ybsV3RzG5BajSygnzArpQfSYSdVnyCgUeMgQeg2ZqBaIDIAsXBhxpdudTFSqij16niWTjOQ8BUrn24..uekVfX6Una9Y9K06Ge7GFzlIZQh7JbzvpK_8ibEEcLXbYUQKqy8h_avEbXxOll_52Pq5NxakzAJdmwqcWsL.WFPhHt39IvW2.83ix9cICTlHr51BWINC3zWeTTnt4vTqyxsuYtC7hKUMKoNlBjvuoIX.YDhUh5ViTweHMvcn2zFv8OktKt.v24zKrrMqvpevfYY8xp2wDKBjah8I7.53p6KnWjZpHFPqlZl.PqxnwLCI5bFiw",mdrd: "WwR4rSxM17ssqg_4iobi1ScB2Rvs_H_2ku7n0f.T9ns-1739778041-1.2.1.1-tAwKYfUA4F7uFa89bBebNGnQqopEFQDG9i6uEOdVhweO2a_k5cmTGlvrTN7jGiuMW_cmPIhTqSwSikloV4H597FhIiBzNoR7NsJULKAhOdQpBuTdunkfLfeOn0UExnl1JnmGTwXBSQ85t4TC4UFml7gYxOkDMS2vWTscypBEY0WZzH_U81H91YWM8cFC_y_H4LigaLm4TjVi0Liuev.guIJcKMIPn_KXLS.byFwJcoOEAuHl84USowgIB3oI0REFGK.5qG7R_WBrMVKVodXUwSTumgXIqvScqqiTD5kvvkRacjDzscScdo2nyVz9ZEMAh3tfgz3B0HLi1IH0iBIlSo4Gk.vz74PBzsTZcSjQoXasDoZVip6JhLVqLFHeqczKysMUye2Z9QbSPxDrhQIgYhEnvmM95icOqTsmFpdBuvBsw0YCNdwr0NHp_o8CZ6MExdGp5eNV8Bjxzf7vYqKAuA8zJwXNezQMyR1svtsozoPB3K6uEEIssRqOprxujWCvhBlitEKYKxQhKip2yONOQaiZ3LJte9iD1X9Z72.xgqWiOsffgolG.tWTtc1sSYxVNy0AzdtgVtmqAYcO4FSs1ewf6tyuxUppXZfWD3Gx7HscsVa1m4K0Pr4WmG8PiaOSqF5Nnch2TlCrzopTfuYPdycIz5KLsAdGJZfZyUoxGRpNFNBewor2Llg1JPClHFrJCuxUYCkXDAfG13MtVBL.bX7rBqr0EyduytWH_4.mYbH3Dah5SrEYE1eLbOj0.pkAa0UHGNynPjwpRd1iaG0y.ETyVE_td.EZVD63bRM4Qph7FS0WmdLnneiYfLi4RrmEU54rp.2FqPcKALOVTRcBZpSz9.yk5RxfshUmhmAH2e3mLVPGNu2IxI9GoYfToMf3GCPRJdyOzqv0qx1Jf.C3S7UEiHqKwboz.Y4euMb7gcxJLcCcoXNioMcSU8Pydyt6oKIXMuJVHJOpe31k81npfRhhnyhBPg44FRCZ3YKIdJW1Wuhn28j3o9QYN3BFT7NihxRAT6AJb8.oIKBzvH1roC2wvlKThlbzP5ap3N7g6raAriTh7FlumJccUvrc7FrQyORGAcxQubLggaY7sWjfUj7f3_zNlpY71_IiQ09IG1RskzE.oUOYcuSSJG54Hydljb8dJIK25.OvxdLMJ_9CdTNBRgirHUGwSB6kd5F80ZUU2GflDytZ7SOLs7erXjUtkNuFen04NTI8oV_Mthw1omT1LYQrxGRCXBlecvCZ4l7VsN1sfhXvbXONAH772KvdESfkq.XSlb28_V0sEEhKmvmoe2MSTz7uu.fDQsDkRU031CCOA8OnrcVM9nR424uIHeiYP7ay4Hbtg_YCpZMoWJjHrhKTP34OaGTqCVttEkjp.ZKVpIJH_Eo_SACRGkE_j1_H_DFFgz46SaeOQzfICuPSgr4tr7Ouh8CPWGPt4MgRgn9ySg0VamvaAG_XCQzru7IHJMYb6s4Rlp3hFuWAfOcK7OnNywEDh5XuHwMPMoNSfvsnyYI029uX4.ERZjqcvaXR4HNIvQyyTvy2vP9.rMMIGlVvZmcuQ0yw_lz.zLHyapqZ0.F8phmqM4d9F3DxaeNDT_ukHIaDuc6HrQccJ5GyezKflYiE7nnM63uidUcDvBINzRIH3_7Vpp0RDuTHvvG2dz5vOkvokbBeNfGjQTQvsm889k2zLwKeI_4VJhKbTw1eaq4xTj5qaLiK9t8sSrXRPldcw.WTdw6vpfH3n14uVTriWC8v4LKg2Dk5P2Zd2Ym5szqK1zaSAiE2Q85j3zWmIQ1R7gwOLugQtwThVvZ2LbSTFYOqjHHa5pXwEJsIV9kRivg190.uvht.6vltE2VqeXFALcbfxvsht60DY2wyNdRGYB7D3fwXCNBKfE01_n6V8F5bdyfOlYfKHWekhdxXsAM1VX36Of7_UeevoqqaEZSBIrOvsVBaOm_WQ6OyeVuF_CFyiQBcTby7P0qTTJrPslqEZT0Tf4cavssXhA"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=913421785b071a58';window._cf_chl_opt.cOgUHash = location.hash === '' && location.href.indexOf('#') !== -1 ? '#' : location.hash;window._cf_chl_opt.cOgUQuery = location.search === '' && location.href.slice(0, location.href.length - window._cf_chl_opt.cOgUHash.length).indexOf('?') !== -1 ? '?' : location.search;if (window.history && window.history.replaceState) {var ogU = location.pathname + window._cf_chl_opt.cOgUQuery + window._cf_chl_opt.cOgUHash;history.replaceState(null, null, "\/abstracts\/search?q=COVID-19&__cf_chl_rt_tk=y.Ht60eF6zvD7aDvC72aKzGGxAShEYCUZKxa1K6vrS8-1739778041-1.0.1.1-8QprQ_LmtpXxRYRvvRTxfZJbPPArSmc1pwwGqEilloc" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>