We are at crossroads in 2021in COVID-19 pandemic. On the one hand, we have several vaccines, novel treatments, by now a set of established public health practices of test, trace, isolate, and on the other: the virus continues to rage, and new cases. Let’s view the emergence of new strains in that light and see where we get to this.
Back in October, when the UK was in lockdown, in Kent and Southwest England, they noted that there was surge in COVID cases. It turned out that there was a new strain of SARS-COV-2 that was responsible for this. Now we know that coronaviruses mutate once every two weeks or thereabouts, but when sufficient number of mutations accumulate, that’s when new variants emerge. This was a new variant as it had over 17 mutations in various places and one of them N501Y mutation was worrisome. The mutation N501Y was able to bind more effectively with the receptors. What does this mean?
First of all, N501Y would mean that at position 501in the genome, the virus would be replacing an Asparagine (N) for Tyrosine (Y), see
Amino Acid (AA) Symbols and Abbrevations
Amino acids are the smallest units of protein. They are organic molecule smade up of amine and carboxylic acid…
But then, with this altered protein, the virus would gain a property of rapidly binding to the receptors through which it was going to gain entry to human tissues (Figure 1)
So, basically now you have a virus that can spread more rapidly than the previous strain that was circulating for most of 2020.
Within days of the announcement of this new strain, we learned about more strains that emerged. The South African strain, for instance, was reputed to be affecting not only the elderly but also younger as the South African authorities figured out new and heightened rates of infections and identified a new strain. They also figured out that this new strain was capable of evading the antibody responses.
So, this brought us to a unique situation in the fight against coronavirus in 2021. We knew for instance, that this virus would preferentially affect elderly people with widespread deaths. We knew, that if we were infected once and recovered, we were assured of some immunity for a very long time; that, convalescent plasma and antibodies raised agains previous infections would be good candidates for treatment. We also believed that antibodies raised against the spike protein and inactivated viruses would be good enough to confer protection for a very long time. Would these still hold?
For now, the answer seems uncertain. One of the things is certain, for instance, is the role of standard public health advices about maintaining physical distances, repeated testing, and once tested to be positive to contact trace and identify the genome of the infection and trace back. Therefore contact tracing, genomics, and public health measures still seem to hold true.
What lies ahead in 2021 is unclear. If the new strains continue to grow as seem to be the case, then we are in for a long haul. It may also turn out that at some point, the mutations will make the virus ineffective to bind with the receptors but sadly, that does not seem to be the case. Vaccines such as mRNA vaccines targeted against the spike protein will still probably work but with what efficacy one needs to question. The vaccines from inactivated viruses will likely to take a hit. A recent analysis from Brazil suggest that the Sinovac vaccine, raised against inactivated viruses, seem to confer about 50% efficacy in terms of its protection. Could this be partly explained due to new strains as new strains continue to emerge and being reported from Brazil as well.