This the fourth part of series of science article looking at coronavirus related issues that are hitting the news headlines. In the first article we looked at face masks; in the second we looked at disinfection; and the third topic was social distancing. This fourth article considers the lockdown, testing and whether the idea of an ‘immunity passport’ is a good idea.
Governments are caught between dealing with the competing urgencies of abating the COVID-19 health crisis and the looming threat of an economic recession. This is complicated due to an approved drug, or better still, a COVID-19 vaccine still a way off, other solutions are in place and different ones are being considered to accelerate communities’ return to normalcy.
In terms of when lockdowns and other measures can be eased, the work of epidemiologists is of great importance.
What is epidemiology?
Epidemiology has traditionally been used to model the spreading of diseases in populations at risk. By applying parameters related to responses to infection and network of contacts it helps to study how diseases occur, why they spread and how one could prevent epidemic outbreaks.
Epidemiology is an area of scientific study that that identifies factors that pose a risk to the health of an individual in relation to a certain disease. In terms of how this relates to the current coronavirus situation, we know that as of late April 2020 more, than 2.5 million cases have been diagnosed globally, with over 176,000 fatalities. But what does this mean going forwards?
Extensive measures to reduce person-to-person transmission of COVID-19 are required to control the current outbreak, such as social distancing, hand sanitisation, and masks. The question is, how well are these working and when will a level of normalcy be returned?
This can only be answered through data. It is important that scientists continue to study the disease and the patterns of infection, so government can assess if controls are working and to make recommendations – hence the role of epidemiology is essential.
Epidemiological changes in COVID-19 infection are being monitored taking into account potential routes of transmission and subclinical infections, in addition to the adaptation, evolution, and virus spread among humans and possible intermediate animals and reservoirs.
However, there remains a considerable number of questions that need to be addressed. These include details about who and how many have been tested, what proportion of these turned positive and whether this rate remains constant or variable. From such analyses specific and detailed public health measures can be implemented.
Immunity passport
Some governments are currently discussing the idea of using “immunity passports” as a means of getting the workforce up and running with those who have recovered from the coronavirus infection.
As an example, to test the feasibility of such strategies, researchers in Germany are launching a mass study to quantify COVID-19 immunity in the population prior to easing lockdown measures. This is coming from the Helmholtz Centre for Infection Research.
The idea is that those who are immune could be issued with a kind of vaccination pass that would for example allow them to be exempted from restrictions on their activity. However, immunity passports have three major issues. These are based on the limitations of current test methods.
Firstly, without widespread access to accurate diagnostic tests, medics are unable to categorically confirm infections. Secondly, on top of this, scientists are still unable to properly define immunity or understand the risks of reinfection and infecting others. Thirdly, dividing up the population may generate resentment with the possibility that social cohesion will suffer.
In response to the pandemic, biotechnology companies have lost no time in developing COVID-19 diagnostic kits, which have flooded markets across the globe. Unfortunately, many of these kits are a let-down in terms of accuracy and reliability.
There are also reports of dubious diagnostic kits made in China making headlines, with chances of getting an accurate result as low as 30 percent (as reported in The Guardian). To make matters worse, any quick, easy, point-of-care diagnostics that provide results in minutes are notoriously unreliable. You should note that the World Health Organization is cautioning against using them.
The problem is that very few of these tests have undergone rigorous testing and validation to ensure their quality and performance. Furthermore, scientists are still unsure whether recovering from COVID-19 gives a person complete immunity against reinfection.
It also stands that medics estimate that it will take a couple of weeks after infection to build up protective levels of antiviral antibodies, but these might only be enough to keep the coronavirus at bay for a few months. There are cases in South Korea that are being investigated in relation to so-called viral “reactivation”, occurring after infection. Or this might be the consequence of inaccurate test kits.
Another complication is that to have protective immunity, a person has to have neutralizing antibodies that no currently-available kit can test for. The diagnostic tests that are available are not able to rule out whether a person who has contracted COVID-19 is still infectious. Patients could continue to shed the virus long after symptoms subside, keeping the risk of infecting others elevated without social distancing measures.
As things currently stand, continued social distancing will be our best way out of the impasse. The video below expands on some of the points raised in this article.
