Here are the top 10 points in this big story:
Omicron does not (at this time) escape detection from existing Covid tests, including the cheaper and faster antigen tests, Health Secretary Rajesh Bhushan told states and UTs, urging them to scale up testing for early identification and management of cases.
At the meeting states and UTs were advised not to let their guard down, and they were reminded of the 'test, track, treat, and vaccinate' mantra '. They were also advised to keep a strict lookout for and focus on emerging clusters and hotspots, as well as augment health infrastructure and home isolation, and widen vaccine coverage.
Dr Nayana Ingole, the current-in-charge of Mumbai's first genome sequencing lab, told NDTV the absence of the 's' gene in RT-PCR samples (that had been processed by DNA sequencers) could indicate infection by the Omicron strain.
"No case of COVID-19 variant Omicron has been reported in India so far," Mr Mandaviya told the Rajya Sabha, adding, "We are immediately checking suspicious cases and conducting genome sequencing. We learnt a lot during the pandemic...Today, we have a lot of resources and laboratories. We can manage any situation."
Yesterday, however, Dr Samiran Panda, Head of Epidemiology at the ICMR, sounded a warning, telling NDTV: "I won't be surprised if there is detection in India. It's just a matter of time, given the high transmissibility this variant comes with."
Last week Mr Bhushan wrote to stress on rigorous surveillance of international arrivals (specifically those from 'at risk' countries) and ensure the prompt dispatch of samples for genome sequencing. "This variant is reported to have a significantly high number of mutations... has serious public health implications..." he said.
The Health Secretary underlined the importance of that order, and the government also said Covid-positive samples of people returning from 'at risk' countries be sent to designated genome sequencing labs (part of the INSACOG network). As on November 26, 'at risk' countries are those in Europe, South Africa, Brazil, Bangladesh, Botswana, China, Mauritius, New Zealand, Zimbabwe, Singapore, Hong Kong, and Israel.
State and UTs have begun tightening restrictions. Covid-positive cases have already been reported in travellers from countries where Omicron is present, but the strain has not yet been confirmed. Airports have begun prepping for large-scale testing starting tomorrow. PM Narendra Modi called for a review on easing of international restrictions.
The Omicron strain - designated a 'variant of concern' by the WHO - is believed to have 50+ mutations, including over 30 on the spike protein, which is the target of current vaccines and is what the virus uses to unlock access to our body's cells. Researchers are still determining if this is more lethal, and if current vaccines protect against it.
Moderna set off fresh alarm bells after it said existing vaccines may not be as effective against Omicron as against Delta. Pfizer is working on a variant of its vaccine. Neither jab is in India though, where Covishield and Covaxin are in use. The Serum Institute and Bharat Biotech have not yet commented on this issue.