Gates Package — page 13

PANDEMIC I - THE FIRST MODERN PANDEMIC throat. Our grantees are also working to design swabs that are cheap and able to be manufactured at large scale but work as well as ones that are in short supply. This self-swab approach is faster, protects health care workers from the risk of exposure, and should let regulators approve swabbing in virtually any location instead of only at a medical center. The PCR test is quite sensitive--it will generally show whether you have the virus even before you have symptoms or are infecting other people. There has been a lot of focus on the number of tests being performed in each country. Some, like South Korea, did a great job of ramping up the testing capacity. But the number of tests alone doesn't show whether they are being used effectively. You also have to make sure you are prioritizing the testing on the right people. For example, health care workers should be able to get an immediate indication of whether they are infected so they know whether to keep working. People without symptoms should not be tested until we have enough tests for everyone with symptoms. Additionally, the results from the test should come back in less than 24 hours so you quickly know whether to continue isolating yourself and quarantining the people who live with you. In the United States, it was taking over seven days in some locations to get test results, which reduces their value dramatically. This kind of delay is unacceptable. There are two types of PCR machines: high-volume batch processing machines and low-volume machines. Both have a role to play. The high-volume machines provide most of the capacity. The low volume machines are better when getting a result in less than an hour is beneficial. Everyone who makes these machines, and some new entrants, are making as many machines as they can. Adding this capacity and making full use of the machines that are already available will increase the testing capacity. The foundation is talking to the manufacturers about different ways to run the big machines that could make them more than twice as productive. Another type of test being developed is called a Rapid Diagnostic Test (RDT). This would be like an in-home pregnancy test. You would swab your nose the same way as for the PCR test, but instead of sending it into a processing center, you would put it in a liquid container and then pour that liquid onto a strip of paper that would change color if it detects the virus. This form of test may be available in a few months. Even though it won't be as sensitive as a PCR test, for someone who has symptoms it should be quite accurate. You would still need to report your test result to your government since they need visibility into the disease trends. A lot of people talk about the serology test, where you give blood and it detects whether you have antibodies against the virus. If you do, it means you have been exposed. These tests only show positive results late in your disease, so they do not help you decide whether to quarantine. Also, all the tests done so far have problems with false positives. Until we understand what level of antibodies is protective and have a test with almost no false positives, it is a mistake to tell people not to worry about their exposure to infection based on the serology tests that are available today. In the meantime, serology tests will be used to see who can donate blood and to understand the disease dynamics. A lot of countries did a good job focusing the PCR capacity on the priority patients. Most countries had their government play a central role in this process. In the United States, there is no system for making sure the testing is allocated rationally. Some states have stepped in, but even in the best states, the access isn't fully controlled.