Iceland’s national broadcaster RÚV reported that a man currently in the coronavirus ward of Landspítali hospital in Reykjavík-Iceland, with the Omicron variant is fully vaccinated and had recently received a booster dose.
He reportedly developed disease severity and had to be hospitalized.
Iceland reported the man’s diagnosis, the country’s first Omicron case, on Wednesday. It has not yet been determined whether his infection is linked to travel.
The case is worrying many doctors and researchers around the world as it indicates that the new variant is capable of immune evasion and is most probably resistant to the current vaccines as it is not only causing breakthrough infections among the vaccinated but there is also risk of increased disease severity and mortality among the fully vaccinated including those with booster shots.
The Omicron variant was found in a person who had travelled to Finland from Sweden, the institute added and said it was still investigating samples from other people travelling in the same group that now were sick with Covid-19.
This brings a total of 26 countries outside of the African continent that has the omicron variant including Austria, Australia, Belgium, Brazil, Canada, Czech Republic, Denmark, Finland, France, Germany, Greece, Hong Kong, Japan, India, Israel, Italy, Netherlands, Norway, Portugal, Spain, Saudi Arabia, Singapore, Sweden, UAE, United Kingdom and the United States.
How fast is Omicron spreading?
Omicron’s rapid rise in South Africa is what worries researchers most, because it suggests the variant could spark explosive increases in COVID-19 cases elsewhere. On 1 December, South Africa recorded 8,561 cases, up from the 3,402 reported on 26 November and several hundred per day in mid-November, with much of the growth occurring in Gauteng Province, home to Johannesburg.
Epidemiologists measure an epidemic’s growth using R, the average number of new cases spread by each infection. In late November, South Africa’s National Institute for Communicable Disease (NICD) in Johannesburg determined that R was above 2 in Gauteng.
That level of growth was last observed in the early days of the pandemic, Richard Lessels, an infectious-disease physician at KwaZulu-Natal University in Durban, South Africa, told a press briefing last week.
Gauteng’s R value was well below 1 in September — when Delta was the predominant variant and cases were falling — suggesting that Omicron has the potential to spread much faster and infect vastly more people than Delta, says Tom Wenseleers, an evolutionary biologist at KU-Leuven in Belgium.
Based on the rise in COVID-19 cases and sequencing data, Wenseleers estimates that Omicron can infect 3 to 6 times as many people as Delta, over the same time period. “That’s a huge advantage for the virus — but not for us,” he adds.
Researchers will be watching how Omicron spreads in other parts of South Africa and globally to get a better read on its transmissibility, says Christian Althaus, a computational epidemiologist at the University of Bern, Switzerland. Heightened surveillance in South Africa could cause researchers to overestimate Omicron’s fast growth.
But if this pattern is repeated in other countries, it’s very strong evidence that Omicron has a transmission advantage, adds Althaus. “If it doesn’t happen, for example, in European countries, it means things are a bit more complex and strongly depend on the immunological landscape. So we have to wait.”
Although genome sequencing is needed to confirm Omicron cases, some PCR tests can pick up a hallmark of the variant that distinguishes it from Delta. On the basis of
this signal, there are preliminary signs that cases, although extremely low in number, are rising in the United Kingdom. “That’s certainly not what we want to see right now and suggests that Omicron could indeed also have a transmission advantage in the UK,” Althaus adds.
If Omicron can dodge neutralizing antibodies, it does not mean that immune responses triggered by vaccination and prior infection will offer no protection against the variant. Immunity studies suggest that relatively low levels of neutralizing antibodies may protect people from severe forms of COVID-19, says Miles Davenport, an immunologist at the University of New South Wales in Sydney, Australia.
Other parts of the immune system, particularly T cells, may be less affected by Omicron’s mutations than are antibody responses. Researchers in South Africa plan to measure the activity of T cells and another immune player called natural killer cells, which may be especially important for protection against severe COVID-19, says Shabir Madhi, a vaccinologist at the University of Witwatersrand.
Madhi, who has led COVID-19 vaccine trials in South Africa, is also part of efforts to conduct epidemiological studies of vaccines’ effectiveness against Omicron. There are anecdotal reports of breakthrough infections in all three vaccines that have been administered in South Africa – Johnson & Johnson, Pfizer–BioNtech and Oxford–AstraZeneca. But Madhi says researchers will want to quantify the level of protection provided by vaccines, as well as prior infection against Omicron.
He suspects that the results will be reminiscent of how the AstraZeneca–Oxford vaccine performed against the Beta variant, an immune-evading variant that was identified in South Africa in late 2020. A study led by Madhi found that the vaccine offered little protection against mild and moderate cases in relatively young people, while a real-world analysis in Canada showed greater than 80% protection against hospitalization.
If Omicron behaves similarly, Madhi says, “we’re going to see a surge of cases. We’re going to see lots of breakthrough infections, lots of reinfections. But there’s going to be this unhinging of the case rate in the community compared to the hospitalization rate”. Early reports suggest that most breakthrough infections with Omicron have been mild, says Madhi. “For me, that is a positive signal.”
Will current boosters improve protection against Omicron?
The threat of Omicron has prompted some rich countries, such as the United Kingdom, to accelerate and broaden the roll-out of COVID vaccine booster doses. But it’s not yet clear how effective these additional doses will be.
Third doses supercharge neutralizing-antibody levels, and it’s likely that this will provide a bulwark against Omicron’s ability to evade these antibodies, says Bieniasz. His team’s work on the polymutant spike found that people who had recovered from COVID-19 months before receiving their jabs had antibodies still capable of blocking the mutant spike. To Bieniasz, those results suggest that people with repeated exposure to SARS-CoV-2’s spike protein, be it through infection or a booster dose, are “quite likely to have neutralizing activity against Omicron.”
reference link :https://www.nature.com/articles/d41586-021-03614-z