Five Years Since the First Omicron Case: A Global Health Milestone

As we mark the fifth anniversary of the detection of the Omicron variant of SARS-CoV-2, it is a poignant moment to reflect on the rapid spread and significant impact of this variant on global health.

Discovery and Initial Spread

The Omicron variant, scientifically labeled as B.1.1.529, was first reported to the World Health Organization (WHO) by the Network for Genomics Surveillance in South Africa on November 24, 2021. The variant was initially detected in laboratories in Botswana and South Africa, with the first known samples collected in Johannesburg, South Africa, as early as November 8, 2021[1].

In the days following its discovery, Omicron quickly spread beyond African borders. On November 26, 2021, the WHO designated B.1.1.529 as a variant of concern and named it "Omicron," after the fifteenth letter in the Greek alphabet. By the end of November 2021, cases had been confirmed in various countries, including Hong Kong, Israel, Belgium, the Netherlands, Australia, and the United States[1].

Global Reach and Variants

Within a month, Omicron had been confirmed in 149 countries, highlighting its rapid transmission. The variant quickly evolved into several subvariants, including BA.1, BA.2, BA.3, BA.4, and BA.5. More recently, subvariants BQ.1 and BQ.1.1 of BA.5 have emerged, and as of September 2024, a new subvariant labeled XEC has been identified in Europe and parts of the United States[1].

Impact on Public Health

The Omicron variant has been characterized by its high transmissibility but relatively lower severity compared to previous variants. Despite this, it has still posed significant challenges to public health systems worldwide. In many countries, including Spain, Omicron cases were reported among fully vaccinated individuals, although vaccination remained effective in preventing severe disease and hospitalization[1].

Vaccination and Public Health Measures

The effectiveness of COVID-19 vaccines against Omicron and its subvariants has been a crucial factor in managing the pandemic. Three doses of a COVID-19 vaccine have been shown to provide protection against severe disease and hospitalization caused by Omicron. Public health measures such as physical distancing, quarantining, ventilation of indoor spaces, and the use of face masks have also played vital roles in controlling the spread of the virus[1][3].

Current Status

As we enter 2025, the world continues to monitor new variants and subvariants of SARS-CoV-2. The WHO remains vigilant, tracking variants of interest and those under monitoring, such as BA.2.86 and JN.1. The emergence of new variants like XEC underscores the ongoing need for global surveillance and public health preparedness[1].

In conclusion, the five-year anniversary of the Omicron variant's discovery serves as a reminder of the dynamic nature of the COVID-19 pandemic and the importance of continued vigilance and cooperation in global health efforts. For expats in Spain and around the world, staying informed and adhering to public health guidelines remains crucial in navigating this evolving health landscape.