Variants of the SARS-CoV-2 virus: do they threaten our hope for a return to ‘normality’, socialising and summer holidays?

Variants of the SARS-CoV-2 virus: do they threaten our hope for a return to ‘normality’, socialising and summer holidays?

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“It has been my philosophy of life that difficulties vanish when faced boldly.”

– Isaac Asimov

Over the past year, we have all certainly faced a constellation of difficulties as a consequence of Covid-19 in the UK and globally. As the current lockdown measures begin to ease, we all hope for a gradual return to some of the ‘normality’ that we knew before Covid-19. Much of this hope arises from the UK’s bold, remarkable and highly successful vaccination programme.

Yet, do the new variants of SARS-CoV-2 virus threaten our hope of socialising and summer holidays returning? One of the four conditions set by the government, to allow restrictions to ease according to the roadmap, is that new virus variants do not change the risk of lifting restrictions. The earliest possible date for unrestricted foreign travel being the 17th May.

When a coronavirus enters a host human cell, it converts that cell into a virus replication machine. During this replication process, the SARS-CoV-2 virus develops mutations or changes when errors occur in copying its genetic code and this leads to new variants of the virus. These new virus variants may have altered virus behaviours and pathogenesis. Mutations are an evolutionary advantage as they may result in the SARS-CoV-2 virus being able to bind better to host human cells or better avoid the host immune response. Thus new variants can be more transmissible, cause more severe disease or increased mortality, although some variants can cause a milder illness. Once individuals are vaccinated, they are less likely to transmit the virus and therefore there is less opportunity for the virus to replicate and mutate.

There are 4000 known variants of SARS-CoV-2, most of which have similar behaviour properties to the original Wuhan virus. If a virus variant is considered to have epidemiological, immunological or pathogenic properties, it is designated as a ‘variant of concern’ by the World Health Organisation & Public Health England. The UK has a world-leading genomic sequencing programme that closely monitors these new variants as they arise: the UK has contributed to half of the sequences in the global SARS-CoV-2 genome repository.

Currently there are 3 important variants of concern globally; these 3 variants all contain mutations in the spike proteins which protrude from their surface. The virus uses these spike proteins to bind to and infect human host cells. The B.1.1.7 variant was first identified in Kent in early autumn last year and despite a second national lockdown (5 November to 2 December 2020) and border restrictions, the B.1.1.7 variant was able to spread to approximately 114 countries. The  B.1.1.7 variant has become the dominant one in the USA, Continental Europe as well as the UK. Hence it is much more transmissible than previously circulating variants. We are not sure why the B.1.1.7 variant is more transmissible, but it is likely that this variant is more effective in binding to host human cells. The P.1 variant first identified in Brazil and the B.1.351 variant first identified in South Africa are also causing a significant surge in infections, hospitalisation and deaths in Brazil and South Africa respectively. The P.1 variant is now present in 30 countries and the B.1.351 variant is present in 51 countries.

Research from the London School of Hygiene & Tropical Medicine estimates that B.1.1.7 infection was associated with 55% higher mortality compared to other strains of SARS-CoV-2, during November 2020 and February 2021 in the UK. Additionally, a paper published in the British Medical Journal last month, by Challen R and colleagues has confirmed that individuals infected with the B.1.1.7 variant were between 32% and 104% (central estimate 64%) more likely to die than equivalent individuals infected with previously circulating variants. The Kent B.1.1.7 variant therefore has the potential to cause substantial mortality compared with previously circulating variants in the UK and globally.

SARS-CoV-2, is unlikely to be eradicated; it will remain endemic. Studies are underway to understand the effect of the current variants of concern on vaccine efficacy, but we believe that current vaccines work against the known important variants of concern.

In a worst case scenario, a new highly divergent vaccine-resistant variant of the virus with altered properties could arise. A continued pandemic will ensue and living with restrictions will be necessary in the near to medium term; then ‘normality’, socialising and summer holidays are unlikely.

In a best case scenario, all nations will work collaboratively to achieve high levels of global immunity by mass vaccination, and ensure that dangerous highly divergent new variants of concern do not arise, as the virus is suppressed globally. Furthermore, coordinated global surveillance to rapidly identify, note the origin, characterise properties and monitor the spread of new virus variants will be needed for many years. The UK is well placed to assist in this international endeavour. We know that we can also adapt current vaccines to counter newly identified variants, and this is achievable in a much shorter timeframe with new mRNA vaccines.

Social interactions and holidays are vital to restore our psychosocial and physical well being. I have been lucky to have spent some time in the last few summers in Normandy, Provence and the Côte d’Azur. As we all look forward to enjoying summer holidays in foreign climes once again, we must collectively take steps to reduce virus transmission and follow any restrictions and guidance in place.

 

Dr Raj Chandok, FRCGP FRSA MSc MBBS DC DFFP DRCOG D Med Ed. General Practitioner. Principal, Dr G.Singh & Partners.

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