A Surrey scientist specialising in disease surveillance, response and prevention is urging everyone who is offered a coronavirus test to take it.

As the South African variant of the virus is found in limited parts of England including Woking and Egham, Professor Alasdair Cook says taking part in the testing drive will help to minimise transmission.

The Professor of Veterinary Epidemiology and Public Health, at the University of Surrey, explains how the strain may have come to be here, and reveals what he knows about how it differs.

He also speaks on the remarkable achievements in science over the last year, and on the infectious optimism of Captain Sir Tom Moore.

What can you tell us about how the South African variant differs in terms of its transmissibility?

We are becoming more familiar with the ways that a virus interacts with our bodies. The first stage in the process is contact with the virus, followed by its entry into our cells. This happens when the spike proteins on the outside of the virus adhere to the surface of our cells. Amongst other changes, both the South African and the UK variants have a change in this spike protein which makes it more adherent and this confers the increased transmissibility. The intensive testing and controls being put in place give us the best chance of minimising transmission but it is a race against time.

If you are invited to take a test, please accept and meanwhile, exercise the utmost care in following guidelines.

And what about the effect it has on the body?

Once inside the cells, the changes that the virus causes lead to the signs of disease with which we are now familiar. There is no firm evidence at present that the South African variant acts differently once it is inside the cells, so we haven't seen any changes in the nature of the COVID disease it causes. However, we must continue to be vigilant and monitor the situation in case any new evidence comes to light. What do you know about the efficacy of the various vaccines on the South African variant; is their level of protection reduced by this particular mutation? Since these are relatively new variants, we must remain open-minded about the protection offered by the various vaccines. However, all the evidence to date is that the vaccines will protect against disease and especially the most severe forms of the disease.

It is less clear how much impact vaccination will have on transmission but again, at present it is reasonable to expect that vaccination will lead to less transmission.

Nevertheless, it is essential for everyone to follow government guidelines to stay at home, maintain social distancing, wear a face mask and maintain hand washing.

What are some possible explanations of how the South African variant came to be detected in Surrey in people with no travel links?

The coronavirus, like all viruses, randomly mutates. Whilst it is not impossible that the same mutation may occur in more than one place, it is more likely that the variant found in people without travel links in Woking and the other locations is the same as that found in those people who did have travel links. So, how did it get here? Remember that even though this variant is more highly transmissible, there is no evidence that it causes more severe disease. Whatever the variant involved, most infected people will not feel unwell or only be mildly affected. However careful they were, they will probably have had some contact with other travellers, a few of whom may also become infected without feeling unwell and these in turn may have infected others. Therefore, this undetected spread is the likeliest way for the South African variant to have arrived in Woking and the other locations. We should appreciate that it is highly probable that further cases of infection with the South African variant will also be found without any known history of travel or contact with travellers. The 11 cases found so far were the result of random checks on five to ten per cent of swabs, so almost inevitably there will be others. Clearly it is an unnerving time for everybody; can you share any good news on coronavirus that may offer people hope? Firstly, it is easy to forget the incredible success of scientists around the world in developing this range of effective vaccines and also of the vaccine manufacturers in scaling up to produce millions of doses. None of this is easy. Secondly, in UK the roll out of vaccination has been very successful and now many of our most vulnerable people are protected. It is tremendously encouraging that the AstraZeneca vaccine has been shown to reduce transmission by up to 67%. Thirdly, we are seeing the tide turning and the rate of spread reducing. Every one of us can contribute to this by continuing to follow Government advice and bearing the hardships it brings. Finally, we can remind ourselves of the inspiring words from the much-loved and sadly lost Captain Sir Tom Moore: 'Please always remember, tomorrow will be a good day'.