A recent study highlights a significant decline in immunity against the evolving Omicron variants of Covid-19 in Kenya. Researchers revealed that both naturally acquired and vaccine-induced immunity, gained during the early stages of the pandemic, is largely ineffective against newer variants. The study, titled “Evaluation of Population Immunity Against SARS-CoV-2 Variants,” was published in the BMC Infectious Diseases Journal on December 28, 2024.
The research, which analyzed samples from 17 counties in Kenya, shows a troubling decrease in antibody efficacy against variants like EG.5.1, BA.2.86, and others. Researchers found that over 40% of vaccinated individuals exhibited no neutralization against the Omicron variants, and fewer than 20% of those with antibodies from prior natural infections were able to neutralize the new strains. These findings underscore the limitations of immunity from earlier vaccinations and infections, as the virus has rapidly mutated.
The study, conducted at reputable laboratories, including the Kemri-Wellcome Trust Research Programme and Kemri-CDC, suggests that the rapid mutation of the SARS-CoV-2 virus has led to the emergence of new variants capable of evading pre-existing immunity. This means that many Kenyans, especially the elderly and those with underlying health conditions, remain vulnerable to severe illness and hospitalization.
Although Covid-19 is now considered endemic, the virus continues to present serious health risks globally. In Kenya, more than 5,000 lives were lost to the disease by 2023, yet active surveillance ceased in 2023, leaving the country without a robust monitoring system.
The study emphasizes the urgent need for updated vaccination strategies, especially targeting the elderly, and genomic surveillance to better understand the virus’s evolution. Researchers also call for the introduction of vaccines tailored to current variants to counter immune escape, a crucial step in ensuring better protection as the pandemic continues to evolve.
