The lessons global, country, and local public health agencies and researchers have learned since the early days of COVID-19 have led us to a greater understanding of how the illness spreads and which populations are the most vulnerable to its symptoms and side effects.
Variants and Vaccines
The U.S. Department of Health and Human Services (HHS) formed a SARS-Cov-2 (COVID-19) Interagency Group (SIG) to monitor emerging variants and their potential impact on vaccines, therapies, and diagnostic tools. HHS included the Centers for Disease Control and Prevention (CDC), the National Institutes of Health (NIH), the U.S. Food and Drug Administration (FDA), the Biomedical Advanced Research and Development Authority (BARDA), and the Department of Defense (DOD) so the agencies can effectively coordinate and evaluate the risks the emerging variants pose to people.
COVID-19 is like other viruses; it evolves as changes occur in its genetic code. These changes are caused by mutations or viral recombination as COVID-19’s genome is replicated. A lineage (a related group of variants stemming from a common ancestor) comes from these changes in genetic code. For example, Omicron has several variants and subvariants derived from its genetic code (BA.5, BQ.1.1, and XBB are a few).
Each of these variants has at least one mutation that differentiates it from the other variants of COVID-19. Researchers compare the differences to keep local, state, and national public health agencies up to date with trends and variants.
Throughout 2022, the dominance of one variant of COVID-19 has changed from one familial offshoot (Delta) to another (Omicron). Within the variants, some subvariants have mutated and can circumvent the protections afforded by earlier vaccines and boosters. Experts have improved on vaccines while changing vaccine and booster recommendations to reflect the ongoing effort to prevent and protect people from harmful, sometimes deadly outcomes.
As 2022 progresses, researchers, infectious disease experts, and public health professionals have continued to examine and follow the updates made to COVID-19 vaccinations and boosters. Because COVID-19 maintains its position as a global public health issue, vaccinations and boosters must adapt to the variations and subvariants of COVID-19.
COVID-19 Variants
January 1, 2022, New York reported its highest number of new COVID-19 cases since the beginning of the pandemic. Two days later, the United States became the country with the highest daily infections in the world. In one week, the number of people hospitalized because of COVID-19 increased by approximately 50%.
Currently, Delta, a COVID-19 variant, was the dominant strain. However, a new variant, Omicron, spread quickly throughout the United States. Soon, Omicron’s number of new COVID-19 cases surpassedDelta, making it the dominant strain.
Delta Variant
As 2020 ended, a new variant, B.1.617.2 (Delta), was identified in India. Delta quickly spread worldwide since its transmission rate was higher than its predecessors. The CDC classified Delta as a Variant of Concern. This variant has an increase in transmissibility, more severe disease, a serious decrease in neutralization by antibodies generated in previous vaccination or infection, a reduction in the effectiveness of vaccines or treatments, or failures to detect the variant in diagnostic tools.
Delta’s new infection rates continued to increase during 2021. However, towards the end of the year, a new variant, Omicron, began to spread. With the rise of Omicron cases and a decrease in Delta cases, the CDC downgraded Delta from a Variant of Concern to a Variant Being Monitored in April 2022.
Omicron Variant
Soon after 2022 began, Omicron (BA.1, BA.1.1, BA.1.1.529, BA.2, BA.3, BA.4, and BA.5 lineages) became the dominant variant of COVID-19. While new case rates from Omicron grew, the hospitalization from Omicron is lower than that of Delta.
Omicron is a highly transmissible variant of COVID-19 and is responsible for a surge in COVID-19 cases globally. The World Health Organization (WHO) declared Omicron a Variant of Concern because it has spread faster than all other previous variants.
The surge in Omicron cases posed a new concern from a public health perspective because of its transmissibility and subvariants. Omicron and its subvariants posed new risks to those with compromised immune systems, seniors, and pre-existing conditions, such as a spinal cord injury (SCI). Omicron aggressively attacks the respiratory system causing severe symptoms and side effects in those with respiratory system issues.
BA.5 Subvariant
During late spring and the summer, Omicron’s BA.5 variant became one of the dominant subvariants of COVID-19. During the spring and summer, BA.5 was considered the most contagious. However, its symptoms and side effects were no more severe than previous Omicron subvariants. The vaccines approved by the WHO and the FDA continued to provide protection against infection, severe illness, or death. Yet, the BA.5 subvariant is easily spread and can evade immunity from previous COVID-19 infections or vaccines.