The genetic structure of SARS-CoV-2, the virus of COVID-19, is the key to unlocking a functional vaccine. And according to a new study, discovering the mutations will provide insights into the pathogen's evolution and efficacy of a vaccine.
The mutations in the genetic structure of SARS-CoV-2 were led by scientists at the University College London (UCL), a public research university in the UK. Their findings revealed 198 recurrent genetic mutations in the virus. These mutations highlighted how the novel coronavirus adapted and evolved to its human hosts. Moreover, the mutations identified were linked to the majority of countries severely hit by COVID-19. Results were published in the journal Infection, Genetics, and Evolution.
Is it Ethical to Buy Nonessential Items During Pandemic?
When the word "mutation" is mentioned by someone, it is thy associated with abnormalities or negative modifications in genetics. Oftentimes, it may be linked to rare diseases and even cancer. However, the core meaning of mutation is change, which can go either for better or worse. In viruses, their DNA or RNA genetic codes can mutate at any time and it may lead to something good, something bad or something neither of the two. Regardless of the outcome, researchers need to detect these mutations to narrow down the spread of the pathogen in a community.
Mutations in the genetic material of a virus matter in vaccine research. The faster the mutation rate is, the more difficult it is for a vaccine research group. For example, the human immunodeficiency virus or HIV, the virus that causes AIDS, can mutate at an incredible rate. HIV is considered to have the highest rate of mutation compared to all known biological entities in the world. Because of its fast mutation rate, HIV vaccine research is outpaced by the pathogen.
On the other hand, the annual influenza vaccine is produced to combat seasonal flu every year. While the influenza virus mutates quickly, it is significantly slower than HIV and has properties shared across strains that stay constant. As such, vaccine researchers need to predict an accurate influenza strain with potential mutations for the next seasonal flu to develop the latest flu shot formula.
According to the Genome British Columbia, a nonprofit organization in Canada, early studies of SARS-CoV-2 indicate that the virus does not have a mutation rate comparable to influenza. This is good news because a functional vaccine can be effective for a long time across all populations. But if the virus does have a fast mutation rate, the vaccine is likely to be effective for a short time and must be recreated at specific intervals like flu shots. As of April 9, 2020, a total of 78 vaccine candidate projects are participating in the global fight against COVID-19.
The Mutations in SARS-CoV-2
The study led by UCL identified almost 200 recurrent genetic mutations in SARS-CoV-2. These mutations were confirmed with high genetic diversity and could be traced to countries gravely struck by the pandemic. The genetic diversity suggested the extensive global transmission of the virus before COVID-19 became pandemic, meaning the transmission might have started in October 2019 in select areas until the situation got out of control.
"All viruses naturally mutate. Mutations in themselves are not a bad thing and there is nothing to suggest SARS-CoV-2 is mutating faster or slower than expected. So far we cannot say whether SARS-CoV-2 is becoming more or less lethal and contagious," said Francois Balloux, a lead author of the study and professor at the UCL Genetics Institute.
The scientists mentioned in their paper that the first entire genome sequence was published on January 5, 2020. After that, thousands of sequences were conducted and showed the genetic characteristics of the deadly pathogen. A dataset comprised of 7,666 public genome assemblies was used by the team. They analyzed the genomic diversity over time using that dataset. Their results showed a common ancestor toward the end of 2019. This common ancestor based on the sequences available supported the SARS-CoV-2 jump to a new host: humans. The results supported the estimated start of the pandemic: sometime from October 6, 2019 to December 11, 2019.
Because of the extensive transmission of the virus between people, the genetic mutations have been widely varied. The results yielded 198 filtered recurrent mutations in the genome of the virus. Though, almost 80% of those mutations produced non-synonymous alterations at the protein level. Scientists interpreted that as a sign of the pathogen's ongoing adaptation. Yet they could not conclude if the virus would have more mutations in the future. Further research would be needed to determine that possibility.
Furthermore, the genetic mutations might indicate the lack of a single index patient. While the diversity in the mutations showed that the virus was unlikely to have been in human communities for long, the variations pinpointed the simultaneous presence of the pathogen in communities. For instance, in the UK, the sequences shared in the territory among other countries represented multiple independent entries. Multiple entries in the UK would unlikely be caused by just one index patient. Multiple index patients might be the likely scenario.
According to the World Health Organization, the total confirmed cases and confirmed deaths due to COVID-19 in Europe were 1,707,946 and 155,552, respectively, as of May 10, 2020. Within 24 hours, 25,608 new cases and 1,319 new deaths were reported by European nations. The European countries with confirmed cases of at least 100,000 were Spain at 223,578, Italy at 218,268, the UK at 215,264, Russia at 209,688, Germany at 137,115, Turkey at 137,115, and France at 137,008. European countries with confirmed deaths of at least 10,000 were the UK at 31,587, Italy at 30,395, Spain at 26,478, and France at 26,268.
Countries with confirmed cases of less than 100 in Europe and associated territories were Greenland at 11, the Holy See at 12, Liechtenstein at 83, and Monaco at 95. Both the Holy See and Monaco reported sporadic cases of COVID-19, while Greenland and Liechtenstein are yet to confirm the reason behind the cases. Sporadic cases would indicate scattered or isolated reports or cases at irregular intervals.
The genetic mutations in the research of COVID-19 are essential in vaccine development. If these mutations exist in areas that the vaccine does not target, there is a good chance that the vaccine will work for a long time. That can give researchers more time to prepare for another vaccine in case new mutations arise.