A quick look at some of the science
As I sit and write this article the country is in lockdown all caused by a tiny virus. The wonder is that something so small can cause such disruption to the whole world with effects that will be felt for a long time. I hope to enlighten you a little about the science involved in the response to this pandemic.
Let's start with the discovery of this virus. Coronaviruses are a large family and get their name from the crown like spikes that surrounded them - but you do need a special type of microscope to see them! They were first identified as a group in 1960 and linked to a range of illnesses, most commonly colds and other respiratory infections. You may have heard of SARS which emerged and then seemed to disappear before it could cause too much trouble globally, although as the death rate was 37% that is just as well. There have been other scares of possible pandemics by coronaviruses since then but our current crisis caused by SARS-CoV-2 emerged at the very end of 2019 when 44 cases of a new viral respiratory illness were identified. Now you may ask how they identified it as new. This is quite complicated, and they did a range of tests on the samples to try and work out what was causing these illnesses, including standard genetic assays. PCR, looking for genes of known viruses, negative results suggested this illness was being caused by a new virus. Tissue culture and electron microscopy identified this infection to be caused by a coronavirus, but distinctly different from any previously seen in human infection.
The next step was to sequence the genetic material (mRNA) before using this to develop specific tests for the virus. Fortunately, technology has moved on and these tests, about 20 different ones, have been developed rapidly, days rather than the years it used to take. I find it staggering that folk are moaning about lack of tests. Do they forget this is a completely new virus? New tests used to take years. I think back to the amount of time and the range of developments testing for other infectious agents took and wonder at how quickly tests have become available. Speaking to an ex-colleague who works in virology, the hospital reference laboratories were primed and ready to go but a lack of reagents, that is chemicals, and the right sort of swabs, was the limiting factor to the number of test that could be carried out, not lack of equipment or personnel. We may look at other countries and see that they have lots more testing available, but to what standard? The questions that have to be asked are 'Are these tests really testing for SARS-CoV-2?' and 'Are these tests detecting all the positives with no false positives?' Imagine being told you have had COVID-19 because the test was positive only to later develop the disease, that is the consequence of the test not being specific enough. Only time will tell which tests were the best. Meanwhile, think about the scientists, in development labs and diagnostic labs across the world working under pressure to get testing up and running.
You may have heard about antibody (Ab) testing. This doesn't look for the virus in the patient but looks for the specific response, antibodies produced, by the patient's immune system. There will be a delay between infection and response so in the early stages of infection Ab levels will be low but it is these that will give lasting immunity, if it develops. Looking for the SARS-CoV-2 antibodies is a bit like looking for a needle in a haystack as there are lots of antibodies in everyone's blood, they are part of our defence mechanism against all infections. The amazing immune system can do all this without us even thinking about it, it is fantastic that the human bodies have built in defence systems.
An antibody response is what is required of a good vaccine. Usually vaccines can take ten years or so to produce as they are required to have extensive testing to ensure they are safe and effective, giving lasting protection against the infectious agent. Scientists and vaccine production companies are in a race to get the first COVID-19 vaccine out but even the most optimistic are suggesting 18 months as a minimum. The problem with vaccine production is selecting the right part of the virus to produce antibodies that give protection against infection, are long lasting, easy to manufacture, and the vaccine must not damage the person being vaccinated. This is complicated by the fact that all humans respond differently to the vaccine which can make it less effective, especially in older people.
All I have been able to do is outline some of the factors. For more information there is an excellent Futurelearn course, COVID-19 (https://www.futurelearn.com/courses/covid19-novel-coronavirus), plenty of scientific articles, as well as Horizon programmes (https://www.bbc.co.uk/programmes/m000h3nm), and if you want the statistics debunked listen to More or Less on Radio 4 (https://www.bbc.co.uk/programmes/p02nrss1/episodes/downloads).
Keep Safe, Stay Home.
Sr Joy Raynor
Provincial Youth and Children’s Officer who formerly worked in a medical testing laboratory