COVID-19: New Variants of the SARS-CoV-2 Virus

Viruses are constantly changing, they mutate, and those changes produce new variants of the virus, some of them disappear and some of them persist. When a virus suffers a mutation (as it happened with SARS-CoV-2 virus) its genetic material changes and the structure of its genome is altered, which produces what we call a new ‘variant’.

On the other hand, we talk about a new ‘strain’ when one of those variants is the result of a significant alteration that confers a modification within its biological life cycle, which can make the virus more aggressive, more virulent, or resistant.

SARS-CoV-2 is a ARN virus that have been gone through multiple mutations since it appeared, however, fortunately it is also a virus that doesn’t change significantly, its mutations arise as a natural result of its replication.

According to WHO scientist have been studying during the last month some new variants that tend to spread faster, and are more transmissible in UK, Brazil, and South Africa. However, these new variants appear to behave similar to the previous viruses and cause the same symptoms.

▌ Can I get infected with a new COVID-19 variant If I had Covid-19?

Evidence is showing us that having COVID-19 do not necessary means protection from the virus, and this applies also to other new variants of SARS-CoV-2. People could get second infections with earlier versions of the coronavirus if they mounted a weak defense the first time, and they can also get a new variant of the virus after suffering from Covid-19 disease.

What this means is that we really need to focus on making sure we do everything we ca to reduce transmission by diagnostic and serological testing, providing supportive isolation, and tracking and monitoring Covid-19 transmission.

▌ Is the vaccine effective for the different variants?

As far as it has been observed, most scientists believe that the vaccines that are currently available should provide protection against UK variant and they also affirm that a couple of mutations in the virus should not make the vaccines ineffective, but there are some studies right now to actually confirm that.

On the other hand, the main companies that produced the available vaccines assure that their compounds will continue to work against these new mutations, but it has already been known that these vaccines lose some effectiveness in the face of the South African mutation. The American manufacturer Moderna had already announced that they will adapt its compound against this mutation.

However, updating a vaccine is not something new, vaccines are adapted every year for example with the seasonal flu.

▌ Is UK, South Africa, or Brazil variant more contagious and more dangerous?

Last studies suggest that the different SARS-CoV-2 variants spread faster and easier than other variants, which means that they can produce more patients suffering from Covid-19. Scientists are working to learn more about how the disease caused by these variants differs from the previous variants, and how these new variants affect existing therapies, vaccines, and tests.

• The UK variant was the first detected in United Kingdom during the end of 2020, it has a high number of mutations, mainly involving the protein called “spike”. It spreads really fast, which means that It is more transmissible, because it is more efficient at entering our cells. Recent data suggest that there is a real possibility that infection with this variant will be associate with more severe COVID symptoms.
• The south African Variant was first detected in Nelson Mandela Bay (South Africa) in October 2020. It is similar to UK variant, it is also a mutation in the spike protein, therefore is it more efficient at getting into our cells and replicating. This variant has also other mutations and may be able to reduce how our antibodies bind to the virus, but this hasn’t been confirmed yet.
• The Brazilian Variant was first detected in Japan, in Brazilian population, at the beginning of 2021, it also has mutations in the spike protein as well as other important mutations, and there is not evidence that it causes severe symptoms, but it is the most concerning variant regarding the effectiveness of the available vaccines.

The new variants of coronavirus share the same key symptoms with the initial variant – including fever, cough, and loss of sense of taste or smell. Groups of scientists are studying all these new variants and they have found so far that people infected with them carry a higher concentration of the virus in their system, which in other viral diseases usually means more severe symptoms.

▌ Do tests detect the different variants?

There are a wide range of different tests currently available, and most diagnostic tests can still be reliable and can diagnose the different virus variants. Based on publicly available data of the 246 molecular diagnostics which have FDA Emergency Use Authorization (EUA) the majority of diagnostic tests have other target that is not the spike protein, and that means the mutations may not affect their effectiveness. Furthermore, the majority of rapid antigen tests with EUA detect nucleocapsid protein, rather than spike protein, so they should be unaffected as well.

However, it is still a question if the rest of the test which just target the spike protein can identify another variant of the virus that experimented spike mutations.

The tests we develop in Immunostep are based on Mpro protein, which is a non-structural protein of the virus and it plays a crucial role in viral replication.  Therefore, these serological tests remain demonstrating 98% reliability even in the face of SARS-Cov-2 mutations.

▌ How difficult and fast is to adapt the vaccines to the different variants?

On one hand, mRNA Vaccines, which are the vaccines that contain material from the SARS-Cov-2 virus (ARNm), or viral vector vaccines which use the virus genetically engineered, could take from one to two weeks to be adapted to new variants. These vaccines can be actualized faster because they just need to change a fragment of the genetic code, they will need to adapta the part of the code that has been modified in the virus as a result of the mutations. This would be the case of the Pfizer and Oxford vaccines.

On the other hand, the inactivate or weakened virus vaccines, which use a dorm of the virus that has been inactivated or weakened, would take a couple of moths to be modified; This would also be the situation of the vaccines that use harmless pieces of proteins shells (protein-based vaccines). There are vaccines of these types available around the world currently being used such as the American vaccine (Novavax) and the Chinese vaccine (Coronavac). These vaccines are more difficult to adapt because they need to grow the virus or the protein in the laboratory and then purify and inactivate it to produce a vaccine, which is a process that take more time.