There is no evidence to suggest that existing vaccines do not work on the Omicron variant of coronavirus, though some of the mutations reported on spike gene may decrease the efficacy of existing vaccines, Rajya Sabha was informed on Tuesday. “There are limited available data, and no peer-reviewed evidence, on vaccine efficacy or effectiveness to date for Omicron,” Union Health Minister Mansukh Mandaviya said in a written reply.He was responding to a question on whether the vaccinations that are given in the country are effective to develop immunity for this variant. “However, vaccine protection is also by antibodies as well as by cellular immunity, which is expected to be relatively better preserved. Hence vaccines are expected to still offer protection against severe disease and, vaccination with the available vaccines remains crucial,” he added.Listing the steps taken by the government after the news of the spread of the Omicron variant of Covid-19 in various countries, Mandaviya said his ministry on the basis of risk assessment reviewed the existing travel guidelines and revised rules for international arrivals were issued on November 28 which were further amended two days later.According to the guidelines, regions or countries have been re-classified as 39 ‘at-risk’ based on the epidemiological situation of Covid-19 there and reporting of Omicron variant from these countries. List of such ‘at-risk’ regions or countries is dynamic in nature and has been updated from time to time. All travellers coming from countries deemed ‘at-risk’ will also mandatorily undergo Covid-19 testing on arrival through RT-PCR, followed by mandatory home quarantine for 7 days, Mandaviya said.A repeat RT-PCR testing shall also be done on the eighth day of arrival in India to be monitored by state health authorities. Two per cent of travellers from ‘non-at-risk’ countries will be tested at random for Covid-19. Individuals tested positive shall be subjected to Whole Genomic Sequencing at identified INSACOG network laboratories to determine the presence of SARSCoV-2 variants (including Omicron). States and union territories have been asked to undertake several activities which include strict monitoring of international travellers in the community, contact tracing of positive individuals and follow up for 14 days, genome sequencing of positive samples through INSACOG Labs in a prompt manner, Mandaviya said.Read all the Latest News, Breaking News and Coronavirus News here.