omicron variant and vaccine

 

For months, scientists have pondered over whether a newly discovered coronavirus mutation found in South Africa could render vaccines less safe. Now it looks as though that question might become more important than ever before amid reports from countries like Britain and the United States of an increase in coronavirus cases linked to this mutant virus.

The first reports came back in early October, but in hindsight some of those reports can be interpreted differently by different news outlets. So let’s take some look on this new variant of Covid - known as named after it and the fact that scientists are still not sure whether it would behave similarly to previous variants.

Coronavirus mutations

Newly identified variants of SARS-CoV-2 (the virus behind COVID-19) generally do not render vaccines useless. The key difference between old and new variant is the sequence deletion or insertion, which has affected the receptor binding domain (RBD). This gene plays an essential role in the receptor binding domain, binding to the ACE2 receptor on our cell surface that carries out the vital task of entering the body and allowing the virus to enter the host cell, infecting the cell and then passing through it to reach the other side of the membrane. It allows for the rapid emergence of new variants of SARS-CoV-2, including the one which has only deletions and is likely to undergo further evolution. These variants have been seen in both the UK and South Africa:

Variants found in South Africa and Brazil

In August 2020, a new SARS-CoV-2 mutant in South Africa was announced, called 501Y. Some initial research suggested that this mutant variant appeared very similar to variants already found in the United Kingdom (variant 501Y) and South African (variant 501A), with similar results coming from tests conducted across China, Australia and South Korea. However – and this is part of a recurring theme – many countries have detected new variants before they had full knowledge of their epidemiology and so it remains unclear how much vaccine protection has been afforded against these variants.

Coronavirus vaccine breakthroughs and impact

The most recent breakthrough, from Pfizer and BioNTech, made headlines worldwide. This news came as a major boost to the global fight to stop the spread of the virus. As of today, all the major vaccine makers (Wuhan Institute of Virology, Moderna, Johnson & Johnson/Janssen, Oxford University, AstraZeneca, Curevac, Glaxosmithkline, and Sanofi /Pfizer) are working in collaboration to develop COVID-19 vaccines for emergency use authorization (EUA) for the UK, U.S., Canada, Mexico, Europe and other countries in 2021 and for use worldwide, possibly as soon as late January/early February. In comparison, other vaccine manufacturers such as Sinovac Biotech (China), CanSino Biologics (the Philippines, Singapore and Indonesia) and Zydus Cadila (the United Arab Emirates and Egypt) have also worked in conjunction to prepare for EUA in the future. A possible timeline for the development and availability of the candidate vaccine is listed below.

Coronaviruses and Variants of Interest

There are currently three main variants of interest. They are:

Variant 501st and 501Y

Variant 437 and 479

Variant 2212

Coronaviruses may evolve quickly, mutate extensively and so there are multiple ways in which one could become infected with a particular version of the novel coronavirus. Some of the mutations in a coronavirus spike protein have been shown to make the virus less efficient in attaching itself to the receptors on human cells; others are likely to alter the virus’s ability to invade human cells, while some could change the structure of the spike protein; and others could affect the antibody response to the virus. Such changes may then contribute to the evolution of the virus – and if enough mutations are present, there may also be a need to re-test the effectiveness of the vaccines. It should be noted that vaccines will be tested in large numbers of people. The data from phase 3 and phase 4 trial phases in China, Russia, Belgium, Ireland, Spain, Italy, France.

Who else?

There are just over 200 known variants of SARS-CoV-2 which, although small, make up 99% of all known coronaviruses. One of the larger number of these variants is named B117, which was reported in December and has a new name because of it being isolated during preparation for vaccination, and its presence appears in one of the vaccine trials. There are also more minor variants: E484K, N501Y, N501Y and E484N. Other minor variants are the E484K, I484M and M484R ones. Although currently in clinical trials, variants which exhibit a lower viral load, are associated with a higher risk and therefore should be avoided for use in long term immunizations. Those with increased viral loads could potentially cause disease more rapidly and therefore needs to be avoided. Another way in which B117 or another minor variant could be used is in the treatment of symptomatic infections. Long-lasting symptoms can be prevented by giving patients two shots spaced over several weeks.

However, the biggest challenge for the public may come in getting vaccinated against SARS-CoV-2 before more information becomes available. Vaccines are typically given in groups of several hundred people in order to get enough participants vaccinated against each new variation of concern. To date, more data on variants of interest than any other vaccine has been released by leading organizations like the Global Consortium for Health Security, Gavi, Fédération Internationale de Immunodérie (FIB) and WHO and, according to Dr. Anthony Fauci, “they still have a lot of work to do to really give the public the best possible protection.” Nonetheless, he said, “there are many groups around the world who are doing real time surveillance” and “certain things are happening right now and we’ll see things like this emerge. And there are certainly indications that we may well see us moving away from a certain set of variants and more towards something completely different, at least in the near future.”

Dr. Fauci said on CNN: “This is definitely a great opportunity to see what kind of variants we see, but I don’t think there’s a particular reason why we’re waiting until now to see the vaccines,” adding, “We are going to move as fast as possible from the variants of interest to something entirely different.”