New strain of Covid virus and tackling mutation
Zubair Khaled Huq
Researchers are tracking virus variants since some of them might be more deadly than the original virus and some variants may be more easily transmissible and can have repercussions on the effectiveness of vaccines. Evolution helps organisms to change in response to certain changes in the environment so that they can survive. Since viruses can only replicate within a host cell, their evolution is influenced by their hosts. This means that the virus will mutate to evade the defences that its hosts put up against it. Once a virus has entered the body of its host, it starts replicating, which means making copies of its entire genetic sequence. This change is called a mutation and if it is a favourable mutation, it can give the virus a new ability that promotes its reproduction, which helps the virus to become more widespread over generations.
It is likely that those kinds of favourable mutations are giving rise to emerging variants. For instance, the UK variant is known to be about 25–40 per cent more infectious than the original virus. To be more effective for any vaccine, resources should be spent on developing ‘pan-virus vaccines’ that can provide immunity against multiple strains of a virus. SARS-CoV-2, the virus that causes Covid-19, keeps changing, generating new and more transmissible versions as the world scramble to stay ahead of a pandemic that has killed millions of people so far.
The more a virus mutates, the less effective a vaccine becomes. In the worst-case scenario, the virus replicates to such an extent that the vaccine is not adequate to help the body to produce the right protection. The good news is that some vaccines, such as those by Pfizer and Moderna, use mRNA technology, which allows for reconfiguring a vaccine to transmit different genetic instructions more easily. Variants are mutations of a virus. All viruses mutate when they copy themselves to spread and thrive. Most mutations, however, are insignificant while some can even harm the virus and others can produce a variant that will make it more transmittable.
A virus spreads inside the body by attaching to a cell, then entering it. They then make copies of their RNA, which helps them proliferate. If there is a copying mistake, the RNA gets changed and that is what scientists call a mutation. All vaccine manufacturers, Pfizer-BioNTech, Moderna, Oxford-AstraZeneca and others are looking at how they can improve their vaccine to make sure that they are ready for any variant — there are about 4,000 variants around the world of Covid-19. One of the aims of working towards herd immunity is to keep vulnerable groups, who cannot get vaccinated due to health conditions like allergic reactions to the vaccine, safe and protected from the disease. A vaccine takes time to give immunity, and if at least 70 per cent people are not immunised within the shortest possible time herd immunity will not be a reality.
However, all these vaccines, through their interaction with the immune system, are expected to reduce infection and virus replication at some level. Oxford/AstraZeneca, Novavax and Moderna have all reported that their vaccines reduce virus transmission. In a nutshell, while the current Covid-19 vaccines provide immunity to the disease, their impact on the transmission of the virus is yet to be fully determined. We must understand their impact to protect those who have underlying health conditions and may not respond to vaccination or cannot be vaccinated.
Besides, people are joining various social functions together with their kids without wearing masks and are not properly maintaining health hygiene and social distancing rules. That is why children, alongside adults, are being infected with the coronavirus. The guardians must remain careful about taking their children to crowded places and social functions. They should also strictly maintain health safety rules and encourage children to wear masks and wash their hands with soap after touching any substances. We have to be aware of the symptoms such as red eye, chest pain, skin blisters, sore throat, headache, diarrhoea, paleness of hand and foot fingers that the new variants are reportedly causing. These symptoms may be present alone or in the group, with or without fever and running nose. If any suspicion arises test is the best option.
Even those who arrive with Covid negative certificates should be sent to quarantine as they may get transmitted with the virus during their travel time. Currently, the RT-PCR tests are doing the two-gene diagnosis. This system may not detect all the mutations of the coronavirus. The chances that the new strain would be detected in the existing tests are slight. It is being discussed whether to change the RT-PCR testing. We should arrange the facilities to do three-gene tests. Besides, genome sequencing of at least five out of every 100 samples should be done.
Scientists are keeping a watchful eye on this variant because it has several mutations in the gene that makes the spike protein of the virus that latches onto human cells. These changes include the presence of the increasingly well-known mutation, called E484K, which allows the virus to partly evade the immune system and is found in the variants first identified in South Africa (B1351) and Brazil. The rapidly spreading variants renew the importance of containing the spread through non-pharmaceutical measures such as wearing masks, maintaining social distancing and practising hand hygiene to prevent further mutations by stopping the spread of the virus from one person to another. It will help to buy time for us to arrange life-saving vaccines from other sources and countries, in addition to the current vaccine.