Kemri researchers cite Omicron sub-variants driving sixth Covid wave

Covid curfew Nairobi

Members of the public, wearing masks to prevent the spread of Covid-19, queue for public transport home at the Kencom bus terminus in the Nairobi central business district, ahead of the curfew hour, on April 7, 2021.

Photo credit: File | Nation Media Group

Researchers from Kemri-Wellcome Trust have established that two Omicron sub-variants are key drivers of the sixth wave of Covid-19.

The two spin-offs, BA.4 and BA.5, are also culpable for fuelling new Covid-19 infections in other parts of the world and preliminary studies show that they are more infectious and more likely to escape immunity compared with previous ones.

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.

Data from Kemri-Wellcome Trust shows the Omicron variant was first detected in Kenya on November 14 and was found in samples collected in Nairobi. 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 in their genetic codes) was conducted in three counties – Nairobi, Kilifi and Kiambu – which cumulatively had 53 samples.

The study was conducted between May 18 and May 31 when the sixth wave was rising exponentially and its results have now been published in 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 brief.

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

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.

The study also shows that though the sub-variants may be fuelling new infections, a separate predictive model that analysed their impact showed that they were unlikely to stretch the healthcare system in Kenya.

A Lake Region Economic Bloc (LREB) committee of experts, in its fifth policy brief, shows that even with available testing kits, there is reduced interest in Covid-19 testing in their region

Interest among the population for Covid-19 testing “is warranted to keep monitoring epidemic dynamics, [and] identify risk groups and potential variants, particularly in light of the increased transmission risks during crowded elections-related activities,” advised Prof Khama Rogo, chair of the LREB committee.

Prof Rogo also said political rallies are a ticking time bomb that could lead to a surge in cases as most public health protocols are disregarded at such events.

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

“The predicted sixth Covid-19 wave in Kenya is occurring during a period of heightened political activities. [A majority] of young people in Kenya are largely unemployed and have free time to attend rallies, which least comply with Covid-19 prevention protocols,” Prof Rogo explained.

“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.”

The LREB committee has urged greater and continued vigilance at the community level and that healthcare providers be motivated to scale up testing for Covid-19.