Eastern Mediterranean University (EMU) Faculty of Health Sciences, Nutrition and Dietetics Department academic staff member Microbiology Specialist Asst. Prof. Dr. Tevhide Ziver Sarp provided information about SARS-CoV-2 mutations. Asst. Prof. Dr. Sarp included the following in her statement:
“With the declaration of the SARS-CoV-2 pandemic by WHO on 11 March 2020, all countries have been struggling with the pandemic for about 1 year without geographical borders. As the pandemic enters the age of 1, corona virus variants that appear one after another in the world increase the concern even further.
What is Mutation and Variant?
Mutation, which roughly means change, is defined as the permanent changes occurring in the DNA or RNA sequence within the genome of a living thing. All viruses undergo multiple mutations while replicating themselves in order to spread and reproduce. RNA viruses such as SARS-CoV-2 undergo more mutation due to the lack of a mechanism to correct errors that occur when reproducing. While most of the mutations do not cause a change in the character of the virus, some mutations can reduce the effectiveness of the virus (as in SARS-CoV-1), others can make the virus more contagious and more dangerous. Changes and differences occur with the mutation in the virus. The new virus that develops, which is different from the original virus, is called a variant.
What are the Variants of SARS-CoV-2?
Although thousands of different variants of SARS-CoV-2 have been identified, there are three variants of concern around the world. The first of these was observed in England in September, the second in South Africa in October and the third in Brazil. In all of these three variants, mutations were detected in the spiny protrusions on the surface of the virus called the S (Spike) protein, which allows binding to the ACE2 receptor in human cells, and these mutations made the variants more contagious.
The UK variant detected in 70% of cases in the UK has been identified in more than 50 countries, and in Turkey's 33 cities. It has been determined that B.1.1.7, known as the UK variant, binds better to the ACE2 receptor with the change occurring. Although there is no data showing that B.1.1.7 causes more serious disease or an increase in the mortality rate, it has been determined that this variant is transmitted more easily and spreads more rapidly in the society. With the increase in the transmission rate of the disease associated with the variant, the increasing number of cases elevates the risk of developing the disease with a more severe course of the disease, especially for the elderly and those with chronic diseases.
The African variant (B.1.351) detected in the majority of the COVID-19 patients in South Africa has been seen in at least 20 countries and has also been detected in Turkey as of February. The South African variant has been observed to reduce the effectiveness of some vaccines to a certain extent. The Brazilian variant (S.1) was first seen in Brazil, especially in Rio de Janeiro. In addition to Brazil, the variant was detected in Peru, Germany, South Korea, Japan and Turkey. As in other variants, S.1 is considered to be more contagious than the original virus.
Effect of Vaccines on Variants
According to scientific studies, there is no evidence that the current vaccines lose their effectiveness against the UK variant. It has been reported that the Pfizer / Biontech and Sinovac vaccines used in our country are also effective against the UK variant.
However, research conducted on Brazilian and South African variants revealed that variants negatively affect the efficacy of vaccines. In some studies, it has been reported that unlike other types of vaccines, inactivated vaccines (such as Sinovac used in our country) are also effective against the South African variant. In addition to the S protein, antibodies can also be formed against other structural elements of the virus due to the presence of the entire virus particle in the content of inactivated vaccines. It is estimated that these antibodies against different structures of the virus provide protection against the variant. The Bhutantan Institute announced that the Sinovac vaccine, which is widely used in our country, is effective against the African variant, but the effect of the vaccine on the Brazilian variant is in the testing phase.
On the other hand, it has been reported that AstraZeneca vaccine has limited effect against the African variant, the effectiveness of Pfizer among mRNA vaccines has decreased by two-thirds, Moderna's antibody production rate has decreased six times, and the effectiveness of Johnson & Johnson and Novavax vaccines has also decreased significantly.
Existing vaccines can be rearranged according to changing variants and made more effective against the virus, as in the flu vaccine. In particular, it is predicted that vaccines obtained by mRNA technology can be adapted to the variant more rapidly than other vaccines. Recently, the increase in local cases in our country has been associated with the UK variant. We need to pay attention to mask, hygiene and social distancing rules in order to be protected from both the original SARS CoV-2 virus and the UK variant, which is predicted to be higher in transmission. Unless it is necessary, we should stay away from closed and crowded environments. If it is inevitable to be in such environments, care should be taken to use double masks and we should follow the measures more tightly. I hope that we will get over these days with the support of vaccination, the capacity to comply with the rules and the common sense of our society. I wish you healthy days. "