Unsupported information is spreading
Dr. Edsel Maurice T. Salvana
More than one year into the COVID-19 pandemic, there is also an equally destructive and pernicious parallel epidemic of misinformation.
While scientists and experts meticulously choose their words backed up with sound data, purveyors of fake news boldly proclaim as gospel many half-truths and factoids taken out of context. Epistemic trespassing, where experts in one field readily dive into otherwise nuanced discussions and declare their opinions as facts, has misled many. Infectious diseases doctors and public health practitioners have been undermined by quacks and self-proclaimed experts, causing a lot of harm. This week, we address misinformation that continues to be shared on social media and online, sowing doubt and undercutting a proper science-based approach to COVID-19.
Unsupported statements from an email that has been circulating on mass testing are dissected, as well as some misinterpretation of newer developments on airborne transmission of COVID-19 and the role of testing for antibodies after vaccination.
Myth #1. It’s been more than a year, why don’t we still have mass testing?
This is a false and misleading statement. Adequate mass testing in the Philippines has been reached in the recent past. Per the World Health Organization guidelines, one of the criteria for the definition of a controlled epidemic is “less than five percent of samples positive for COVID-19, at least for the last two weeks.” This was achieved by the country from December 2020 to late February 2021. The current high positivity rate is a result of the surge, but with the ECQ, MECQ, and other interventions, this has been going down steadily. Haphazard testing can artificially bring positivity rates down, but this is not a meaningful way to properly achieve control. With more robust pandemic responses, the positivity rate will go down to manageable levels in the near future.
Myth #2: Testing 10 to 20 percent of a nation’s population per day would (sic) lead to rapid reopening.
This is false and impossible for most countries to achieve. First, there is no nation in the world, except perhaps very small nations, that have enough resources to test one-tenth of its population in one day. In the Philippines, that would mean over 10 million tests at a cost of P30-60 billion a day.
Taiwan has done about 600,000 tests (2.5 percent of the population); China has done 160 million tests (12 percent of the population); and New Zealand has done about two million tests (40 percent of the population) since the start of their respective pandemics and all these countries have very good control of their cases.
Doing testing on 10 to 20 percent of the population per day is unrealistic, wasteful, and logistically impossible. The US has done a total of 460 million tests in a country with 330 million people—the most number of tests by any country to date. A 10 percent of the population per day testing rate in the Philippines would mean that we have to test as many as the US has tested during its entire pandemic in a just over 40 days—an absurd proposition with no basis in reality.
Misleading Fact #1: Out of 1,000 Filipinos, only 85 get tested for COVID-19 per day.
This number is not meaningful without proper context. If one lives in Batanes where there are zero new COVID-19 cases, why would there be a need to test anyone? Testing for the sake of testing is wasteful and illogical if there is no risk of disease. Testing appropriately includes considering pretest probability and the test’s sensitivity and specificity. Any number is meaningless unless taken in the context of disease prevalence and the purpose of testing.
Myth #3: Studies show that countries that test more have lower fatality rates.
This is false. The world’s leader in testing, the US, has one of the highest fatality rates in the world as well as the highest absolute number of fatalities. The document says “studies” but does not cite any. Gibraltar, which has the highest testing rate per capita globally, also has the second highest deaths per million population. It is not the amount of testing alone that is important but the availability of testing in combination with other control measures that determine how many people are infected and how many people die of COVID-19.
Misleading Fact #2: The Philippines ranks low at 110 out of 172 countries for total tests performed relative to its population.
This fact does not mean much without any context. Japan and Taiwan have done less testing than the Philippines relative to its population and these two countries have done well. We rank 115th in number of deaths per million population. Many countries (US, France, UK, Spain) rank higher than us in total tests relative to their populations but they have more than 10 times our number of deaths. Testing and testing rates should be seen within the context of need and demand, not as numbers in isolation.
Myth #4: We are fighting a fire blindfolded (pertaining to inadequate testing).
This is not true. There is a state-of-the-art genomic surveillance system that is keeping track of variants of concern. RT-PCR and antigen tests are being properly deployed among symptomatic and close contacts, especially in surge areas.
Haphazard testing is not an efficient means of interrupting transmission. According to a recent Lancet Infectious Diseases paper by Kucharski and his colleagues, the effect of randomly testing five percent of the population every week (which is very expensive) is a reduction of a mere two percent in transmission. When testing is properly done and targeted, it can decrease transmission by 60 to 80 percent, RT-PCR sensitivity is variable throughout the disease course and testing asymptomatic patients especially those without recent exposure has a very high false negative rate.
Testing is important to guide interventions, contact tracing, and for surveillance. It is not, however, a panacea for controlling the pandemic. The proper way to manage case numbers is with the minimum health standards with face mask (85 percent effective), face shield (78 percent effective), and other interventions as shown in Table 1. Testing is essential, but only as part of a comprehensive set of interventions. Focusing on testing as a cure-all is an inefficient and misguided exercise with no sound basis in public health.
Table 1. Interventions and corresponding reduction in transmission
Myth #5: WHO has finally “admitted” that COVID-19 is airborne.
This is a false and misleading statement. WHO already recognized early on that COVID-19 can be airborne in hospitals, especially when doing aerosol-generating procedures. It later updated this guidance to include the possibility of transmission in indoor settings with poor ventilation. There is no specific admission since this has already been acknowledged from the very start. A recent Lancet letter on “airborne” transmission of COVID-19 is still consistent with our current understanding of how people get COVID-19. Masks and faces shields still work. There is now more emphasis on improving ventilation in enclosed spaces, and people should avoid taking their masks off in these places. Best evidence still indicates predominantly droplet transmission, with a possible airborne component, especially indoors.
Myth #6: You need to test for COVID-19 neutralizing antibodies to ensure that your vaccine worked.
This is false. The US Centers for Disease Control does not recommend testing for antibodies, whether IgM, IgG, or neutralizing antibodies after vaccination. This is because different vaccines induce different types of antibody responses, and different antibody tests measure different types of antibodies. Even purported “neutralizing antibody tests” can be inaccurate since there are no agreed upon standards on what constitutes protection. The best assurance for protection of vaccines is from the clinical trials and real-world efficacy studies.
A person’s immune response to the vaccine includes not just antibodies but also cell-mediated immunity. Cell-mediated immunity in the form of T-cells is particularly important for preventing severe disease since these cells are responsible for recognizing virus-infected cells and destroying them before the virus can propagate. There are clear robust T-cell responses from all the approved COVID-19 vaccines, and there is good evidence that these also protect against the new variants.
With the latest COVID-19 surge starting to abate, we need to remember how scary the full hospitals and emergency rooms were so that we continue to take full precautions as we open up our economy. As more vaccines arrive, we need to boost people’s confidence in these injections since they represent the fastest way out of the pandemic. Stamping our fake news and misinformation is crucial toward achieving the goal of a COVID-19-free Philippines.