HomeNewsTrendsHealthOmicron risk remains 'very high': WHO

Omicron risk remains 'very high': WHO

Omicron is behind rapid virus spikes in several countries, including those where it has already overtaken the previously-dominant Delta variant, the WHO said in its COVID-19 weekly epidemiological update.

December 29, 2021 / 08:14 IST
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Source: Reuters
Source: Reuters

The risk posed by the Omicron variant is still "very high", the World Health Organization said Wednesday, after COVID-19 case numbers shot up by 11 percent globally last week.

Omicron is behind rapid virus spikes in several countries, including those where it has already overtaken the previously-dominant Delta variant, the WHO said in its COVID-19 weekly epidemiological update.

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"The overall risk related to the new variant of concern Omicron remains very high," the UN health agency said.

"Consistent evidence shows that the Omicron variant has a growth advantage over the Delta variant with a doubling time of two to three days and rapid increases in the incidence of cases is seen in a number of countries," including Britain and the United States, where it has become the dominant variant.

COVID-19 Vaccine
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How does a vaccine work?

A vaccine works by mimicking a natural infection. A vaccine not only induces immune response to protect people from any future COVID-19 infection, but also helps quickly build herd immunity to put an end to the pandemic. Herd immunity occurs when a sufficient percentage of a population becomes immune to a disease, making the spread of disease from person to person unlikely. The good news is that SARS-CoV-2 virus has been fairly stable, which increases the viability of a vaccine.

How many types of vaccines are there?

There are broadly four types of vaccine — one, a vaccine based on the whole virus (this could be either inactivated, or an attenuated [weakened] virus vaccine); two, a non-replicating viral vector vaccine that uses a benign virus as vector that carries the antigen of SARS-CoV; three, nucleic-acid vaccines that have genetic material like DNA and RNA of antigens like spike protein given to a person, helping human cells decode genetic material and produce the vaccine; and four, protein subunit vaccine wherein the recombinant proteins of SARS-COV-2 along with an adjuvant (booster) is given as a vaccine.

What does it take to develop a vaccine of this kind?

Vaccine development is a long, complex process. Unlike drugs that are given to people with a diseased, vaccines are given to healthy people and also vulnerable sections such as children, pregnant women and the elderly. So rigorous tests are compulsory. History says that the fastest time it took to develop a vaccine is five years, but it usually takes double or sometimes triple that time.
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