New Chikungunya vaccine must be tested for efficacy in West Africa, scientists say
Scientists in Africa are calling for in-human testing in Senegal of the highly anticipated new Chikungunya vaccine, following the detection of a novel strain of the virus that is driving one of the largest outbreaks of the disease in West Africa.
Rapid response urged for novel variant driving major outbreak
By Di Caelers, Nature Africa, 16 February 2024

Houriiyah Tegally, CERI’s head of data science.Credit: CERI@SU
Tulio de Oliveira, director of the Centre of Epidemic Response and Innovation (CERI) at South Africa’s Stellenbosch University, says it’s crucial to determine the efficacy of the vaccine, now approved in the United States, against the new variant.
The Chikungunya variant in Senegal was identified within weeks of the first case in July 2023, thanks to a strong genomics surveillance programme created through a collaboration between CERI, Africa’s largest genomics facility, and Senegal’s Institut de Recherche en Santé, de Surveillance Épidémiologique et de Formations (IRESSEF).
Abdou Padane, who trained at CERI and now heads IRESSEF’s Genomic Surveillance Unit, says his team identified the novel strain of the West African Chikungunya genotype when they began investigating cases in Ndiormi and Bandafassi, in the Kedougou district.
At least 300 cases have been confirmed, and Padane says the epidemic appears to be spreading north, with cases being identified in more urban areas of Senegal.
Chikungunya, an arbovirus transmitted by Aedes mosquitoes, is known for causing acute fever and long-term musculoskeletal pain, and can result in death. Under-reporting is common due to limited diagnostic capacity in rural areas, and because the clinical symptoms often mirror those of diseases like malaria.
These first-ever whole genomes produced in Senegal and made public, together with a detailed scientific report within only a matter of weeks, marked a significant advancement from the previous genomes, which took eight years and had to be sequenced in the United States, said De Oliveira.
'This work was done in Africa by Africans in real-time,' he added.

Abdou Padane, head of IRESSEF’s Genomic Surveillance Unit.Credit: CERI@SU
But it had raised questions about the efficacy of the new Chinkungunya vaccine, which comes from 'a very distinct part of the evolutionary tree of Chinkungunya'. This is different from the East-Central-South Africa (ECSA) strain of the virus, which the vaccine uses.
'While we expect that the current vaccine will still be effective, it would be wise to determine this in real-life,' De Oliveira urged.
The scientists further warned that the Chikungunya outbreak in Senegal comes as temperatures are rising sharply in the country, specifically in the Kedougou district. Along with human habitats close to forested areas, this provided ideal conditions for amplified transmission, Padane said.
Houriiyah Tegally, CERI’s head of data science, said the collaborative work was an example of her centre’s goal of supporting African countries to urgently heighten surveillance and preparedness strategies for emerging infectious diseases, especially in the context of climate change.
Nature Africa, doi: https://doi.org/10.1038/d44148-024-00056-3
News date: 2024-02-16
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