Experts don&rsquo t know exactly how contagious the highly mutated omicron  variant is, but the virus&rsquo spike protein &mdash which binds to human cells &mdash has mutations associated with higher transmission and a decrease in antibody protection.

&ldquo The profile of the mutations strongly suggest that it&rsquo s going to have an advantage in transmissibility and that it might evade immune protection that you would get,&rdquo U.S. infectious disease expert Dr. Anthony Fauci  told NBC&rsquo s &ldquo Meet the Press&rdquo on Sunday.

That said, some doctors believe that the existing vaccines will be able to provide some protection against the new variant.

Our bodies generate a &ldquo whole host of different antibodies&rdquo in response to vaccines, said Dr. Syra Madad, a fellow at the Belfer Center for Science and International Affairs.

&ldquo I do think that our current vaccines will hold up to a certain extent, with this new variant,&rdquo she told CNBC&rsquo s  &ldquo Capital Connection&rdquo   on Wednesday, noting that the vaccines were able to provide protection against delta.

&ldquo It may reduce vaccine effectiveness by a couple of notches, but that is yet to be seen,&rdquo she said. Current vaccines, along with boosters should still provide a &ldquo good level of protection,&rdquo she added.

Leong agreed that a three-dose vaccine regimen would likely protect against severe disease, but pointed out that many countries still have low vaccination rates.

He said omicron is &ldquo threatening the whole world&rdquo with a sudden surge in cases, and health-care systems could be overwhelmed, even if only 1% or 2% of the cases end up in hospital.