The variant B.1.1.529 was labelled as a Variant of Concern on and given the name Omicron on 26th Nov 2021. Omicron is a highly divergent variant with around 26-32 mutations in the spike protein with potential for immune escape and higher transmissibility. As on 16th Dec 2021, Omicron has been reported from all 6 WHO Regions and over 89 countries (WHO) including many States in India. 

Evidence available around Omicron is still preliminary and more data and research is needed for the same. Early evidence around Omicron is detailed as below.

Effect of Omicron VOC on; 

1.         Transmissibility 

·Omicron is at least 3 times more transmissible than the Delta VOC (MoHFW)

·Omicron has substantial growth advantage over delta (WHO)

·In countries with community transmission by Omicron, doubling time is between 1.5-3 days (WHO)

·Omicron is spreading rapidly in countries even  with high level of population immunity (WHO)

·Higher rate of transmission from an Index case. Secondary attack rate of 21.6% as compared to 10.7 % by Delta (UK study) 

2.         Disease severity 

·Data on clinical severity is still evolving as there is a time lag between increase in cases and hospitalizations or deaths. 

·Hospitalizations in UK and South Africa continue to rise daily- countries most affected by Omicron. 

·“It is too early to conclude if Omicron is more or less severe than other VOCs. However, early data suggestthat the severity may be potentially lower than for the Delta variant and even if this is the case, it isexpected that hospitalizations will increase as a result of significant increases in transmission. Morehospitalizations will put a burden on health systems and lead to more deaths, particularly with shortdoubling”- WHO 

3.         Impact on Diagnostics / Test Kist 

·Available RT PCR kits and Rapid Antigen tests is effective in detecting Omicron as per available evidence. Further genomic sequencing will follow up as necessary. 

 

4.         Effect on VACCINES / Immune evasion

·Reinfection by Omicron appears to be higher than with other VOCs (South Africa/UK Study)

·Preliminary data suggest a fall in neutralizing titres against Omicron

·Two doses of available vaccines appear to have reduced effectiveness against omicron on Infection, symptomatic disease, and hospitalization (WHO)

·South Africa reported vaccine effectiveness of the Pfizer BioNTech-Comirnaty vaccine of 33% against infection and 70% against hospitalization (Preliminary data)

·Though humoral immune response may be reduced, initial data indicates 70% of Omicron epitopes may not be affected by T- Cell recognition which will mean cellular mediated protection against severe disease may be preserved. 

·Vaccines remain the most effective intervention against severe disease and death– against circulating VOC and possibly against Omicron. 

5.         Impact on Available Treatments/ Therapeutics 

·Corticosteroids and IL-6 blockers are expected to remain effective.

·“Preliminary in vitro data published in preprints suggests that some of the monoclonal antibodies developed against SARS-CoV-2 may have decreased neutralization against Omicron”- WHO

6.         Public Health and Social Measures 

·The use of well fitted masks, physical distancing, ventilation of indoor space, crowd avoidance and hand hygiene remain key to reducing transmission of SARS-CoV-2, even in the context of emerging variants. However, PHSMs may need to be enhanced to further limit interpersonal contact, to control transmission with a more transmissible variant- WHO 

 

In view of the emerging evidence and the start of festivities in the State, the following measures are strongly recommended to avoid a post festival surge and a third wave:

1.     Use of masks is highly effective in reducing transmission of any Variant of concern.  Everyone should wear a mask in public places especially in crowded areas, social or indoor gatherings. 

2.     All citizens should celebrate responsibly by limiting gatherings, crowd avoidance and adhering to responsible measures like use of mask and hand hygiene. One life is more worth than an event postponed or cancelled. 

3.     COVID-19 vaccines are expected to be highly effective against severe disease and death for any variant of concern. Vaccines are strongly recommended to avoid more deaths and the unvaccinated or those who have not availed second dose should receive it timely before the third wave. 

4.     Anyone with COVID-19 like symptoms should come forward for testing and avoid crowd or public spaces. 

5.     Travellers should strictly adhere to laid down SOPs and monitor their health and symptoms. 

 

Issued in Public Interest by Department of Health and Family Welfare, Nagaland.

 

(DIPR)