London, Dec 16 (IANS): With the heavily mutated Omicron variant of Covid supercharging booster vaccine debate in rich countries, the world will face a deficit of 3 billion Covid-19 vaccine shots by early next year, the World Health Organisation has warned.A

According to the global health body, while richer nations will "aggressively" boost adults and open up immunisation to children, the rollout of jabs in poorer nations will get more impacted, the Financial Times reported.

Due to the presence of more than 30 mutations on its spike protein, Omicron is said to undermine vaccine performance. Several studies involving Covid vaccines by Pfizer, Moderna, J&J, as well as Sinovac have shown that two doses are not sufficient. On the other hand, a third dose has shown to ward off the new variant.

As a result, rich countries including the US, UK and European nations are increasingly pushing for booster programmes, making supplies "very, very tight".

At the same time, only about 7 per cent of people living in low-income countries have received at least one dose of any shot. And 98 countries - about half of those globally - have not reached the WHO target of immunising 40 per cent of their populations, the report said.

"There is a scenario where very aggressive consumption of doses by high-coverage countries to conduct paediatric vaccination and provide booster doses to all citizens... could lead to a constrained supply situation for the first half of 2022," Tania Cernuschi, the WHO's technical lead for global vaccine strategy, was quoted as saying.

"The gap in the first quarter of 2022 could be about 3bn," she said, adding that about 120 countries had started booster programmes, and 30 were vaccinating children.

"Clearly, if there's also stockpiling of doses in the face of uncertainties (on Omicron and vaccine efficacy), then this could further exacerbate the situation. It's a scenario that is possible with the impressive growth in the number of booster and paediatric programme," Cernuschi said.

WHO Director General Tedros Adhanom Ghebreyesus said on Tuesday that indiscriminate boosting without substantial evidence to underpin it would "repeat the vaccine hoarding we saw this year and exacerbate inequity".

Currently, the WHO recommends administering a third dose of any WHO-approved vaccine to those who are immunocompromised. It has also recommended a booster for recipients of the Chinese vaccines who are older than 60, where supplies allow. It has said vaccines should be used alongside public health measures, such as the use of masks, for the greatest effect.

Meanwhile, Aurelia Nguyen, managing director of the Covax - the international vaccine sharing scheme - said that after months of struggle the Covax programme has started picking up pace, but the fast spreading Omicron shouldn't revive Covid vax nationalism.

So far, Covax has delivered 693 million vaccines, and expects to hit between 800 million and 1 billion by the end of the year. But even those figures, if reached, would be half of the original 2 billion target.

"Right now, we need to avoid a type of scenario which would be 'Vaccine nationalism 2.0'," Nguyen was quoted as saying by the South China Morning Post.

Nguyen said that it was essential to maintain "sustainable, regular supply" that in the coming year, come what may, while avoiding "a type of scenario where you have rich countries that tie up the supplies of a new (variant-adapted) vaccine."