Kenyans have lost significant immunity against new Covid-19 variants, particularly those from the Omicron family, according to recent studies. Research indicates that both natural immunity from prior infections and vaccine-induced immunity, particularly from early vaccinations, have significantly diminished in effectiveness against the evolving virus.
The country’s Covid-19 vaccination campaign began in March 2021, initially prioritizing healthcare workers, teachers, and the elderly. By May 2022, approximately 8.3 million adults had received full vaccinations, which represented 30.7% of the adult population. However, despite these efforts, the rapid mutation of the SARS-CoV-2 virus has rendered much of the immunity gained from earlier waves of the virus and initial vaccinations less effective.
Researchers analyzed samples from 17 counties across Kenya, which were tested at reputable laboratories including the Kemri-Wellcome Trust Research Programme and the National Public Health Laboratory. The results revealed a concerning reduction in antibody efficacy against newer Omicron subvariants, such as EG.5.1, FY.4, BA.2.86, JN.1, JN.1.4, and KP.3.1.1. Over 40% of vaccinated individuals showed no neutralization against these variants, and fewer than 20% of those who had been naturally infected during earlier waves of the pandemic were able to neutralize the newer strains. This decline in neutralization capacity is particularly alarming, as it indicates that many people who were previously protected by either vaccination or natural immunity are now vulnerable to reinfection.
The findings underscore the virus’s ability to evolve rapidly, with new variants emerging that can evade immunity from previous infections and vaccinations. This ability to escape immune protection means that the virus has a higher chance of spreading and causing illness, even in individuals who were previously protected. The study emphasizes that this phenomenon could lead to increased infectivity, transmissibility, and pathogenicity of the virus, making it even more difficult to control.
The study also highlights the growing concern of reduced genomic surveillance in Kenya, which has declined since 2023. As a result, the data from this study was largely limited to two counties, Kilifi and Nairobi, and may not fully represent the national situation. Despite the decline in surveillance, the study’s findings are clear: Kenya’s current immunity levels are insufficient to protect the population against emerging variants, particularly the more recent Omicron subvariants.
Given these findings, there is a pressing need for updated vaccination strategies in Kenya. The study calls for a focus on booster shots with vaccines targeting the currently circulating variants. This is especially important for the elderly, who remain at high risk for severe illness and death from Covid-19. While the disease is now considered endemic, it continues to cause significant health issues globally, including hospitalizations and fatalities, particularly among older adults and those with underlying health conditions.
The study’s authors also emphasize the importance of resuming active surveillance and genomic sequencing to monitor the virus’s evolution more effectively. As the virus continues to mutate, it is crucial that Kenya adapts its response to ensure that its population remains protected. Without these measures, the country risks facing a surge in cases, with potentially severe consequences for public health.
