Omicron offers limited protection against symptomatic disease caused by emerging sub-lineages: WHO
India Today
The World Health Organisation (WHO) said that recent evidence suggests that Omicron infection offers only limited protection against symptomatic disease caused by the emerging sub-lineages of the variant. It said that all countries should emphasise on Covid-19 vaccination.
The World Health Organisation (WHO) said that evolving evidence suggests that an Omicron BA.1 infection offers only limited protection against symptomatic disease caused by the emerging sub-lineages of Omicron. The WHO, with the support of the Strategic Advisory Group of Experts (SAGE) on Immunization and its Covid-19 Vaccines Working Group, is reviewing the emerging evidence on the increasing seroprevalence rates against SARS-CoV-2 globally.
The health watchdog is also keeping a watch on the characteristics and potential benefits of hybrid immunity. Hybrid immunity is defined as immune protection in individuals who have had one or more doses of a Covid-19 vaccine and experienced at least one SARS-CoV-2 infection before or after the initiation of vaccination.
This statement from WHO reflects the current understanding of hybrid immunity and highlights the gaps in evidence and potential implications for vaccination schedules and strategies.
As per WHO, current evidence suggests that immune protection against severe outcomes due to infection and vaccination is more robust than that due to infection, or vaccination alone. This is based on infections with the ancestral SARS-CoV-2 or pre-Omicron VOCs.
WHO said, "The duration of protection from hybrid immunity has not been fully characterized yet and it is unclear whether hybrid immunity will continue to provide strong protection against new variants.Emerging evidence suggests that Omicron infection offers limited protection against re-infection with Omicron sub-lineages. Irrespective of infection history, achieving high primary vaccine series coverage remains the foremost priority."
"Countries and implementing partners should emphasize the urgent need to fulfill this primary objective by calling for vaccination of all adults, focusing on healthcare workers, immunocompromised individuals, and older persons in line with the SAGE Prioritization Roadmap."
It added, "Booster doses are associated with enhanced protection against Omicron and high-priority use groups should similarly be prioritized for these. WHO SAGE continues to review the evidence as it becomes available."
