May 13, 2020
To: All Domestic Employees
From: Pandemic Working Group
Re:COVID-19: New Antibody Test ~ Places of High Risk ~ CA Reopening
New Antibody Test
据报道由商业内幕，雅培公司已经宣布，它将推出一个新的冠状病毒抗体测试（表明患者已被病毒在过去被感染），将出货百万本周检测试剂盒。这些套件将有雅培的测试设备（如图为单位 - 从雅培的网站）的实验室，它可以运行时速100-200测试。雅培预计，这将是能够生产四月份400万套，并于6月20日万美元。CNBC报道称，FDA已经批准紧急使用授权的检测试剂盒，前两天。
据制造商，测试发现抗体冠状病毒阳性者100％的时间（这就是所谓的灵敏度）和冠状病毒阴性的人没有抗体的时间（称为特异性）99％。这些测试查找IgG抗体，这是由身体的二次免疫系统产生的，可以持续几个月，可能几年（而不是在曝光后立即产生的lgM抗体的抗体）。当然，它仍然还不知道的IgG多久抗体冠状病毒通常保持在一个人，也不需要什么级别的抗体来抵御病毒的未来。尽管如此，如果按照规定的检测试剂盒进行，这是向前迈进了一步，因为从各种渠道很多早期的测试工具还远远不够精确。As pointed out in the New York Times today, pursuant to a concept known as the “base rate fallacy,” where the rate of a test’s inaccuracy (e.g., it is 80% accurate, therefore 20% inaccurate) exceeds the actual rate of infection in the population (e.g., 5%), the study results will tend to yield a far higher number of “positive” results than one might expect – in our example, for every five “positives,” only one would be true, while four would be false. Extrapolating those results to the entire population would be unwarranted. In short, before proceeding with antibody testing at scale, it is important the public uses test kits that have high degrees of sensitivity and specificity, and Abbott may have produced just that.
Places Where Transmission Risk is Highest
A helpful piece by researcher Erin S. Bromage, PhD., entitled “The Risks – Know Them – Avoid Them,” was picked up by the national media earlier in the week. In his article, Dr. Bromage uses concepts from immunology and infectious disease to answer the question of what to avoid during pandemic reopening. Before getting to the punch line, he asserts that, as a rule of thumb, the key to achieving infection is Dose x Time. Where exposure (such as through sneezing or coughing) is high, risk can be high even if the time is short. However, even where exposure is low or moderate, excessive time spent will also increase the risk. His focus was largely on infection through air droplets, as opposed to “fomite” or shared surfaces.
Dr. Bromage reports that, historically, the places of greatest spreading have not been grocery stores and inconsiderate pedestrians, but, rather, meat packing plants, large family gatherings (such as weddings, funerals and birthday parties) and closely-configured workplaces (like call centers) and business conferences (such as the Biogen Conference in Boston last March). With respect to reopening, he recommends that we be cautious about indoor activities involving yelling or singing (e.g. choir practice), restaurants with tight seating and/or unfavorable air flow, and indoor group activities that have inadequate social distancing over extended periods of time (e.g., movie theaters). In summary, he recommends that, when entering the “reopening” world, we take account of the environment and make judgments based upon Dose x Time. In this vein and in the interest of protecting our employees, we continue to observe social distancing protocols at our facilities.
As reported by ABC7, yesterday, California Governor Gavin Newsom announced modifications to his stay-at-home order to allow for more businesses to reopen in the state. As you know, AMVAC has been operating continuously throughout the pandemic as an essential business within the country’s critical infrastructure. However, many other businesses do not share that status. In particular, the governor laid out the criteria for sitdown restaurants, including disposable (or frequently cleaned) menus, no pre-set table settings, avoidance of shared salt/pepper/ketchup containers, pre-rolling utensils in napkins, requiring diners to fill their own take-out boxes, thoroughly cleaning tables and chairs after one use and no table-side food preparation. He also directed that shopping malls (for pickup only), outdoor museums, botanical gardens, car washes, and pet grooming facilities may resume operations. Governor Newsom continues to take a measured approach toward reopening in the face of what the L.A. Times described today as a “stubborn plateau” in both confirmed cases and fatalities from the coronavirus. Above (from the L.A. Times) cyclists engaged in a low-risk activity on a path near the Queen Mary.
If you have any questions or comments on this advisory, please contact firstname.lastname@example.org@amvac.com.