how dangerous is the new Covid-19 variant and do vaccines work?

The speed with which the Omicron variant has swept around the world has astonished scientists, but while there was every reason to feel gloomy after its discovery there are reasons to be cheerful in what it tells us about the course of the pandemic.

What are the main differences between Omicron and other Covid-19 variants?

The most obvious is that Omicron is much more highly transmissible than Delta, the previous dominant strain which itself was more highly transmissible than variants before it. For example, Australia previously managed to halt transmission entirely but could do nothing to prevent the spread of Omicron. New cases in the UK were doubling every 2 to 3 days after the variant took hold in the community.

Does that make it more deadly?

Although researchers studying the situation in South Africa, where Omicron originated, have found that while there were vastly more cases in the Omicron wave, a far smaller share were hospitalised (4.9 per cent versus 18.9 per cent for Beta and 13.7 per cent Delta) and of those hospitalisations, a much smaller share had severe symptoms (28.8 per cent versus 60.1 per cent and 66.9 per cent, respectively).

Why is it less severe?

Omicron caused so much concern after it was discovered because it contains a distinctive and alarming combination of more than 50 genetic mutations. However, it seems to do much less damage to the lungs, whereas previous variants would often cause scarring and serious breathing difficulty. In studies on mice and hamsters, Omicron produced less-damaging infections, often limited largely to the upper airway: the nose, throat and windpipe.

Researchers at the University of Hong Kong studied bits of tissue taken from human airways during surgery and discovered, in 12 lung samples, that Omicron grew more slowly than delta and other variants did. Now several studies all publishing their initial results over the last 10 days have come to the same conclusion: that the variant multiplies more in throats and causes less serious disease.

So, Omicron has less impact in all age groups?

No. Unfortunately, in the South Africa study, a much larger share of Omicron hospitalisations were children this time, probably because of very limited vaccination in that group and the sheer number of people infected with Omicron in such a short space of time.

How are the vaccines holding up against Omicron?

Well, but not as well as against previous variants. If someone has had only two doses of the AstraZeneca vaccine then the efficacy of the jab against the Omicron variant is reduced to just 10 per cent. However, a Pfizer or Moderna booster vaccine significantly improves that person’s immunity, up to around 70 per cent. Hence why the Government went all guns blazing on a booster programme for all adults at the end of the year. And all the current vaccines remain effective against severe disease and death, according to the World Health Organisation.

Will a new Omicron vaccine become available?

The big pharmaceutical companies have said they will continue “at full speed” with plans to develop an updated Omicron-based vaccine, which should be available by March 2022 if needed. Pfizer has said that if needed it could produce an Omicron-tailored vaccine in “approximately 100 days” if the variant proves resistant to its current vaccine. Moderna has said it will take the company three months to develop such a vaccine. Novavax has already started creating a Covid-19 vaccine based on Omicron’s known genetic sequence and is believed to have begun testing and manufacturing it.

Does Omicron’s comparative mildness mean the end of the pandemic is in sight?

No. Although it is good news that the virus has mutated into a milder version, its speed of transmission means it is causing just as many problems as past variants. And there will always be concerns that another variant causing equal damage will emerge from countries and continents where vaccine coverage is low – as has been the case with Omicron.

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