好运彩

  • <acronym id="11166"></acronym>
    <code id="11166"></code><acronym id="11166"></acronym>
  • <dd id="11166"><u id="11166"></u></dd>

      <var id="11166"></var>

      1. Advertisement
        Opinion

        Editorial: Widespread coronavirus testing won’t help end the pandemic if it’s inaccurate

        Coronavirus antibody test
        A scientist presents a coronavirus antibody test at a lab in Jena, Germany, on April 3.
        (Jens Meyer / Associated Press)

        A surge of new coronavirus antibody tests, some of them used in studies that appear to show a far greater rate of infection and recovery than we’d imagined, has set the world to dreaming.

        Maybe so many people have been infected that the actual fatality rate from COVID-19 is too low to justify closing down so much of our day-to-day lives. Or maybe a positive antibody test could be used as a kind of “passport” to work and normal life, since that person theoretically couldn’t be sickened and couldn’t pass the virus on to others. Or better yet, maybe we are nearing herd immunity, in which high numbers of immune people keep the disease from sickening the population at large, enabling the public to be set free from their homes.

        For now, sorry to say, those are just dreams.

        Unlike the diagnostic “PCR” tests that measure whether someone has contracted COVID-19, antibody tests look at a body’s immune system for evidence that an individual has been exposed to and defeated the disease. The nation is awash in more than 120 antibody tests for the novel coronavirus that were approved by the Food and Drug Administration without requiring the usual verification of accuracy. The agency was attempting to get the tests out quickly and avoid a repeat of the unconscionable delays in producing the PCR tests, which remain in too short supply.

        Advertisement

        But having plenty of tests won’t help if they’re inaccurate, and some of the antibody tests have unacceptably high rates of false positives. Such mistakes give people the dangerous belief that they’re safe from the disease and an even more dangerous belief that they can’t infect others. Those who show up at a medical office for antibody testing are unlikely to know exactly which test they’re being given and what its accuracy rate is.

        Even with very accurate tests, the presence of antibodies doesn’t necessarily mean immunity; too little is known about the resistance that antibodies provide to reinfection. If that immunity exists, it’s also unclear how long it will last.

        The studies that purportedly showed that vastly more people have been infected — such as one conducted by Stanford University that concluded the number of infected Santa Clara County residents was 50 to 85 times what had been reported so far — have come under criticisms for alleged shortcomings in their methodology. It’s not easy to find a random sample of people for antibody testing; Stanford recruited via social media, and the people who volunteered might be skewed toward those who had suffered COVID-19-like symptoms or who knew they had been exposed. The results also were released before the study had been peer-reviewed, which is happening a lot these days because of the pressure to learn more about this new virus.

        But even if that many people had been infected, and even if they had immunity as a result, and even if that immunity could be counted on to last at least several months — we’re piling up the “ifs” here — we’d still be woefully short of what’s needed for herd immunity. Saying “50 to 85 times more” sounds like most of the population. In fact, that would add up to, at most, a little more than 4% of Santa Clara County.

        Advertisement

        And even if COVID-19 has a significantly lower fatality rate than originally thought, that doesn’t mean it couldn’t kill a lot of people. Given that the virus is easily spread through casual contact and there are no known treatments, if there is no broad-based social distancing, a fatality rate of less than 1% could still exact a horrendous toll.

        Antibody tests could still play an important role in understanding the spread of COVID-19. But as with so many aspects of the disease, more attention to science and verification are needed. The FDA needs to figure out which tests are worthy of approval and which aren’t, and then allow only the former on the market. More robust studies using those tests are needed to give us a better idea how widespread the infections have been, and those are coming. Indiana is planning one that will involve 20,000 people, with special attention paid to obtaining a more random selection of participants.

        And unfortunately, we‘ll have to wait to find out more about the role of antibodies in preventing future infection, and, we hope, to obtain an effective vaccine from the more than 80 under development. That’s our best chance at herd immunity. Yes, science and government need to move quickly against a fast-moving virus, but speed isn’t a substitute for reliable information.


        Newsletter
        A cure for the common opinion

        Get thought-provoking perspectives with our weekly newsletter.

        You may occasionally receive promotional content from the Los Angeles Times.
        Advertisement
        同江| 丹巴| 当雄| 夏邑| 顺平| 孟连| 登封| 成武| 将乐| 开鲁| 黑山头| 克东| 曹妃甸| 南召| 海南| 镇宁| 肥西| 博乐| 千阳| 巫山| 威宁| 靖远| 大兴安岭| 白云鄂博| 蒙自| 洛隆| 台安| 敦煌| 晴隆| 大连| 乌鲁木齐牧试站| 喜德| 兴和| 景县| 安国| 陈巴尔虎旗| 东沟| 吉林| 锡林浩特| 巨鹿| 兴和| 斋堂| 宝应| 齐齐哈尔| 富顺| 和丰| 广元| 临猗| 康定| 吉林| 凤县| 瓜州| 文成| 岳阳| 仪陇| 辰溪| 福州| 睢阳区| 齐河| 大同| 抚顺| 九寨沟| 吉兰太| 野牛沟| 全椒| 晋洲| 盘县| 塞罕坎| 阳原| 泰顺| 布拖| 青冈| 根河| 塞罕坎| 凤山| 杜蒙| 乌拉特中旗| 陆川| 曲靖| 祁门| 阿克陶| 万山| 荥阳| 固阳| 霞浦| 内邱| 闽清| 呼和浩特| 六枝| 灵寿| 普兰| 歙县| 饶平| 金州| 柞水| 灌云| 英山| 京山| 内黄| 托克逊| 江城| 石渠| 光泽| 沂水| 祁县| 南宁城区| 蒲江| 天池| 岳池| 肃宁| 信丰| 华宁| 二连浩特| 宣城| 廉江| 恭城| 林甸| 铁岭| 那日图| 大田| 永安| 卢氏| 白杨沟| 沿河| 永宁| 大佘太| 青河| 富宁| 博湖| 自贡| 任丘| 泾源| 壤塘| 鸡泽| 东台| 松溪| 台江| 揭阳| 扶余| 凤山| 藤县| 武胜| 镇宁| 果洛| 安国| 博罗| 成县| 临沭| 平远| 伊吾| 德格| 广平| 开封| 三水| 新乐| 滨州| 高淳| 顺昌| 营山| 祥云| 顺德| 安顺| 来安| 建宁| 榆中| 秦皇岛| 新洲| 无棣| 北票| 青阳| 大名| 松溪| 黑山| 德兴| 涠洲岛| 头道湖| 乐业| 宁陵| 保靖| 象州| 科尔沁左翼中旗| 新巴尔虎左旗| 绿葱坡| 石景山| 三门峡| 宜宾县| 卓资| 丽江| 吉水| 囊谦| 奈曼旗| 宝鸡县| 沂水| 彝良| 昌都| 陵水| 福安| 建平| 尉氏| 汨罗| 金州| 黄骅| 铁干里克| 盘县| 云县| 白城| 通化| 安新| 平谷| 深圳| 安庆| 银川| 周至| 平乐| 江山| 黑山| 冷水滩| 余江| 安国| 镇海| 柳江| 英吉沙| 葫芦岛| 双牌| 景谷| 梅河口| 崇仁| 永兴| 马山| 河池| 阳山| 南靖| 郑州农试站| 珊瑚岛| 汶上| 青龙山| 阿巴嘎旗| 扎赉特旗| 宁明| 襄城| 固阳| 浠水| 鸡西| 博湖| 都昌| 三亚| 新巴尔虎右旗| 维西| 肇州| 土默特左旗| 张家界| 东光| 图里河| 汝州| 武都| 惠农| 柳林| 朱日和| 裕民| 九台| 南溪| 石河子| 旬邑| 江城| 太白| 安远| 万盛| 灵石| 马鞍山| 沁水| 封丘| 武汉| 南城| 龙南| 铜仁| 松桃| 寿县| 乐清| 加查| 淄川| 天池| 独山| 睢宁| 杭锦旗| 胡尔勒| 斋堂| 鄂州| 忠县| 临潭| 南丹| 长治| 开封| 涡阳| 新平| 佛爷顶| 林芝| 平湖| 定海| 涟水| 托里| 北塔山| 泰州| 招远| 呼和浩特| 兴和| 金山| 靖江| 无极| 石台| 陈巴尔虎旗| 子长| 进贤| 长春| 紫阳| 湖州| 荣县| 万盛| 昌黎| 横山| 洛川| 武强| 高平| 乌拉特前旗| 陶乐| 察尔汉| 襄阳| 石炭井| 甘谷| 库车| 依兰| 枝江| 夏县| 遵义县| 建始| )| 秦安| 沐川| 长治| 汝阳| 瑞昌| 得荣| 顺义| 阜平| 杭锦后旗| 阿里| 南京| 达日| 清水| 胶州| 曲周| 临高| 安远| 汝阳| 扶余| 和县| 扎赉特旗| 大兴| 淮安| 五大连池| 眉山| 杭锦旗| 信丰| 龙陵| 涞源| 延安| 一八五团| 遂宁| 纳溪| 上川岛| 巴马| 鹤庆| 崇武| 额敏| 长安| 太平| 咸丰| 阿尔山| 巫溪| 武陟| 万州龙宝| 隆昌| 柞水| 弋阳| 公馆| 嵩明| 满都拉| 红柳河| 安义| 新干| 宜宾农试站| 金佛山| 通化县| 林甸| 壤塘| 长宁| 泗阳| 头道湖| 江城| 庄浪| 黎平