COVID-19: OIST Insights #3 - How we can best prevent virus infection and accurately identify the virus?

OIST is collaborating with an Okinawa's newspaper Ryukyu Shimpo for a series of column articles related to COVID-19 on weekly basis. The second story of the series was written by President Peter Gruss and Provost Mary Collins.

The article is in Japanese, but please see below the original draft in English.

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In this article, Dr. Mary Collins and I explain how we can best prevent virus infection and accurately identify the virus after infecting patients.

A pandemic is a natural phenomenon driven by evolutionary forces which are beyond the control of humans. Homosapiens emerged merely 200,000 years ago. Viruses have a billion-year history.

Thankfully, in caring for each other, humans have devised measures to prevent or even treat viruses.

There is no vaccine available as yet to combat COVID-19. Until we have one, we need other means to prevent infection.

Measures like wearing face-masks, closing schools, or cancelling public events, can of course help, but they will only have a moderate effect.  OIST Professor Simone Pigolotti showed convincingly that the most effective way to prevent infaction is through a ‘lockdown’, requiring people to stay at home whenever possible, avoiding groups, and leaving only for essential tasks like shopping or taking exercise.

The critical task is to prevent transmission of the virus from contact with infected people, whose breathing and coughing will expel it into the air you inhale. You can also pick it up from direct contact with these infected patients, or by touching surfaces they have touched. Do this, and the virus can easily find its way to your mouth and nose. This is why disinfection and additional hygiene measures are so essential.

Alongside these prevention measures, we need to develop rapid and accurate COVID-19 tests.

How can we detect COVID-19 infected people?

Detection of the COVID-19 genetic material by a method known as polymerase chain reaction (PCR) is accurate and sensitive.

At OIST, we are participating in the Okinawa Prefectural Government COVID-19 PCR testing program.  At the moment it takes up to one day from receiving samples to transmitting the result. This testing time could be reduced by technical improvements; eventually it should be possible to get the result within an hour.

Who should be tested by PCR? This test detects active COVID-19 virus infection in their nose and throat, so it identifies people who are likely to transmit the virus.  In Japan and Okinawa, people with COVID-19 symptoms identified by a physician are tested, as are their close contacts.

More proactive PCR testing would also be possible. As an example, a rapid test could be administered before travel by plane or ship. To avoid congestion at points of departure, travelers could be tested near their home immediately before setting out. This type of testing could also be applied to crowded events such as the Tokyo Olympics.

Testing the whole Okinawan population by PCR test is probably not relevant. In order to survey the spread of COVID-19 in Okinawa a different kind of test is required, namely the detection of antibodies against the virus in the blood. This reveals who has been infected by the virus and recovered. Unlike the virus itself, which comes and goes, antibodies persist long after the infection is over.

In collaboration with the Okinawa Prefectural Government, Professor Matthias Wolf at OIST will supply lab-based antibody tests to survey thousands of hospital patients from across Okinawa for anti-COVID-19 antibodies. This will provide a picture of COVID-19 spread.

In future, there will probably be home tests for COVID-19 antibodies, using a finger prick to take a small blood sample. Use of the present home test kits is controversial, however, as they do not seem to be very accurate or reliable.

For some viruses such as measles, mumps and rubella, a single childhood infection provides protection from repeated infection for many years. However, for COVID-19 it is too soon to say how long the immune response will last, or how much protection it will provide. Other human coronaviruses, such as those that cause common colds, do not seem to generate lasting immune responses, whereas the SARS coronavirus does induce lasting protection. So, it would be unwise to assume that anyone is protected against COVID-19, if they have had a mild infection and a positive antibody test, until more research has been done.