The Omicron variant was first identified in South Africa, in a region with relatively low rates of vaccination. But making a link between the two is not straightforward.
The virus mutates as it jumps between people as well as within a sick person. So in a population with a low vaccination rate, there will be more infected people around, and a greater opportunity for the virus to change.
But potentially harmful mutations can take hold when the virus faces new challenges like vaccines – so a population with some immunity but with the virus widely present is a perfect environment for new mutations to emerge.
It follows that a highly vaccinated population where infection rates are low probably provides the best barrier against potentially harmful mutations.
The challenge is to get from a low to a high-vaccination environment as quickly as possible.
Professor Rowland Kao, a veterinary epidemiologist says “A mix is the worst thing, but unfortunately we all have to pass through having that mix to get to the other side.”.
Another factor is how many people in a population have suppressed immune systems and could be ill with the virus for a long time, giving it more chance to mutate.
One theory is that Omicron emerged in an immunosuppressed person or population – possibly with untreated HIV – which is a big problem in the southern African region. But this is very difficult to prove without knowing exactly where it first emerged.
The first real-world data showing that the new variant Omicron may evade some immunity has been reported by scientists in South Africa; however, UK research suggests some promising signs that booster vaccines could help to fight it.
Scientists have analyzed nearly 36,000 suspected re-infections in South Africa to look for any changes to re-infection rates (catching it twice or more) throughout the pandemic.
They showed there was no surge in the risk of re-infection during either the Beta or Delta waves. This is despite laboratory studies suggesting those variants had the potential to evade some immunity.
However, they are now detecting a spike in re-infections. They have not tested each patient to prove it is Omicron, but they say the timing suggests the variant is the driving force.
The World Health Organization (WHO) has said the world should not panic about the new Omicron variant of Covid-19 but it should prepared.
Speaking at a conference on Friday, top WHO scientist Soumya Swaminathan said the situation now was very different to a year ago.
Reports suggest Omicron has been found in close to 40 countries.
It is still unclear if the highly mutated variant is more transmissible or better able to evade vaccines.
Early data reported by scientists in South Africa – where the variant was first detected – suggests Omicron may evade some immunity to Covid-19, although experts caution the analysis is not definitive.
Also read: COVID-19 Delta Variant: What we know
Writing by Tola Oguneye