The number of COVID-19 cases has more than doubled in Armenia, Azerbaijan, Belarus, Georgia, Russia, and Ukraine over the past week, the World Health Organisation's (WHO) European office warned on Tuesday.
"As anticipated, the Omicron wave is moving east — 10 eastern member states have now detected this variant," Dr Hans Kluge, WHO Europe's regional director, said in a statement.
More than 828,000 new cases were reported across WHO Europe's 53 member states on Monday — going below the one million threshold for the first time since 11 January. The region recorded a pandemic high of more than 2 million new daily infections on 26 January.
Russia reported a new record of more than 197,000 infections on 10 February with Omicron blamed for 60% of all new cases. The country is the hardest hit in Europe with more than 341,000 fatalities.
Kluge stressed that "vaccination remains our best defence against severe disease and death for all current COVID-19 virus variants circulating" and that rates in eastern Europe remain low.
"Less than 40% of those aged over 60 in Bosnia and Herzegovina, Bulgaria, Kyrgyzstan, Ukraine and Uzbekistan have completed their COVID-19 vaccine series. Bulgaria, Georgia and North Macedonia are also among those countries where under 40% of health care workers have received at least one dose of COVID-19 vaccine," Kluge said.
In Russia, which was the first country in the world to roll out a national vaccination campaign, only about half of the 146 million population have been vaccinated so far.
Kluge appealed to "governments, health authorities and relevant partners to closely examine the local reasons influencing lower vaccine demand and acceptance, and devise tailored interventions to increase vaccination rates urgently, based on the context-specific evidence".
WHO Europe also stressed that the spread of the new variant is putting health care systems under increasing strain, warning of an increase in the number of health care workers being infected from 30,000 in December to 50,000 in January.
"As health needs increase, the number of staff available to deliver care has fallen, and the risk of transmission in healthcare settings has risen, further compounding the problem," Kluge said.