Studies: Two Omicron sub-variants fuelling Kenya’s sixth Covid-19 wave

People wearing masks walk in a Nairobi street.

People wearing masks walk in a Nairobi street. Researchers from Kemri-Wellcome Trust have established that two Omicron sub-variants are the key drivers of the ongoing sixth wave of Covid-19.

Photo credit: File | Nation Media Group

Researchers from the Kenya Medical Research Institute (Kemri-Wellcome Trust) have established that two Omicron sub-variants are the key drivers of the ongoing sixth wave of Covid-19.

The two spin-offs, BA.4 and BA.5, are also behind Covid-19 infections in other parts of the world, with preliminary studies showing they are more infectious and more likely to escape immunity, compared to previous Omicron sub-variants.

The sub-variants were first discovered in South Africa earlier this year but are yet to be given an official name as they are still classified as variants of interest.

According to data from Kemri-Wellcome Trust, the Omicron variant was first detected in the country on November 14 in samples collected in Nairobi.

6,277 samples sequenced

Since the onset of the pandemic, researchers have sequenced about 6,277 samples of the coronavirus to detect possible mutations.

The latest genomic surveillance (tracking the spread of the variants and monitoring changes on their genetic codes) was conducted in three major counties in the country – Nairobi, Kilifi and Kiambu – that cumulatively had 53 samples.

The study was conducted between May 18 and May 31 when the sixth wave was rising exponentially in the country and its results have now been published at Kemri-Wellcome Trust’s 51st Policy brief.

“We report predominance of the BA.4 and BA.5 Omicron sub-variants that have been associated with a surge of cases in South Africa. None of the newly sequenced cases had a history of recent international travel,” says the policy brief.

Apart from the two, which were found to be dominant, two other sub-lineages were also detected; BA.2.12.1 and BA.2.

Out of the cumulative samples from the three counties, 22 were BA.5 and 14 were BA.4.

Sub-variants BA.2.12.1 and BA.2 had 11 and six cases, respectively.

Unlikely to stretch healthcare system

The study also shows that inasmuch as the sub-variants may be fuelling new infections, a separate predictive model which analysed their impact showed that they were unlikely to stretch the country’s healthcare system.

The eminent committee of the Lake Region Economic Bloc (LREB), in its fifth policy brief, shows that despite availability of testing kits, there is a reduced interest in Covid-19 testing in their region.

“Continued (motivation of population for) Covid-19 testing is warranted to keep monitoring epidemic dynamics, identify risk groups and potential variants, particularly in light of the increased transmission risks during crowded election-related activities,” Prof Khama Rogo, the chairperson of the LREB eminent committee, advised.

Rallies a ticking time bomb

Prof Rogo added that increased political rallies across the country are a ticking time bomb for a surge in infections since most public health protocols are disregarded at such events.

The policy brief shows young people aged 40 years and below are most likely to be affected.

“The predicted sixth Covid-19 wave in Kenya is occurring during a period of heightened political activity. The majority of young people in Kenya are largely unemployed and have free time to attend rallies, which least comply with Covid-19 prevention protocols. Compounding this is the debilitating vaccine hesitancy, particularly among the youth in Kenya. Immunity raised during previous Covid-19 infections is waning, particularly rapidly with respect to Omicron immune escape variants,” he explained.

The committee has since advised that there should be increased and continued vigilance at the community level and that healthcare providers should be motivated to scale up testing for Covid-19.