Almost two years have passed since the coronavirus emerged and a pandemic broke out. The virus has spread across the globe and its consequences can be seen both in terms of human health and life and the health of the economy. Already at the beginning of the pandemic, researchers suggested that there was more than one strain and that mutations would characterise ever new manifestations. Over time, the scientists' words proved to be true. What are the differences between the SARS-CoV-2 variants, what is the reason for the split and which strain is currently present? We answer.
Table of contents:
- Multiple mutations of the virus
- Statistics based on public data
- Disease risk dependent on virus variant?
- Delta mutation
COVID-19 is a disease with extremely high levels of infectivity. As the virus spreads, it can mutate, thereby creating new variants. Some of these can lead to a more severe course of the disease.
Many mutations of the virus
Viruses are constantly mutating and this is not only true of SARS-CoV-2. Each time the virus replicates, small genetic changes can occur which, by causing mutations, adapt to the conditions and effectively infect more organisms.
Scientists may refer to individual variants of mutated viruses as 'variants' of the original virus.
RNA-series viruses are characterised as having a relatively low mutation rate, but since the pandemic broke out, thousands of new variants of SARS-CoV-2 have emerged, many of which have died and others have become even more potent. New strains appear on average every 11 days, the researchers say.
Statistics based on public data
It is important to remember that the figures are estimates based on positive sampling and do not represent the total number of cases. All data and statistics are based on publicly available data at the time of publication. Some information may be out of date, so it is worth checking the epidemiological situation on an ongoing basis.
Disease risk dependent on virus variant?
Three variants of the COVID-19 virus are prevalent in Poland. These are:
- Alpha (B.1.1.7)
- Gamma (P.1)
- Delta (B.1.617.2)
The different variants have different characteristics. COVID-19 is still being extensively studied, but there is currently no clear evidence that any new variant causes a more severe course of the disease. What is certain, however, is that some may spread faster and more easily.
According to current data, variant B.1.1.7 can transmit 30-50% more than the original virus. Some evidence suggests that it is this variant that may be associated with higher mortality rates.
It remains important for researchers to continue monitoring the new variants and their characteristics, particularly in terms of:
- Rate of spread
- Disease severity
- Effect of drugs and vaccines
Delta mutation
The coronavirus variant, Delta, has been classified by the WHO as one of particular concern as it may have increased transmissibility. This variant was first identified in India in December 2020 and has quickly become the most common variant in the country. Delta currently shows 40 to 60 per cent increased transmission compared to the previously dominant alpha variant.
This variant is particularly dangerous for people who have not acquired immunity. Receiving the full dose of vaccination largely protects against the disease and, if infected, reduces the risk of severe infection and death.
The WHO is warning that it is the Delta variant that will wreak havoc during the 4th wave of the pandemic. The only effective way to prevent this is to achieve population immunity through mass vaccination.
