The study by the Oxford University investigated the ability of monoclonal antibodies in blood from recovered people and from those vaccinated to neutralize the Delta and Kappa variants.
The so-called Indian-variants have been detected in Kenya. It is believed that the Covid-19 variant is more deadly than previous strains.
Last week, an analysis by the Public Health England (PHE) showed that vaccines made by Pfizer Inc and AstraZeneca offer high protection of more than 90% against hospitalization from the Delta variant.
The latest Oxford study results are built on the recent analysis by PHE, the company said.
The Delta variant is becoming the globally dominant version of the disease, the World Health Organization’s chief scientist Soumya Swaminathan said last Friday.
Yesterday, the Health Ministry said the number of patients in ICU had risen from 103 to 273, with 204 of them on ventilator support. CS Mutahi Kagwe said the country’s death toll rose by 23 to 3,484. CS Kagwe says all are late reports confirmed after audit of facility records in June.