February EYE Strategy Newsletter

‘EYE on yellow fever’ podcast – Episode 10 ‘The Road to 2026’  

All ten episodes of the first series can be accessed via your preferred app here or on our website here. A new series will be published in the Spring. 

Laboratory Technical Working Group (LTWG) update

Important information for your laboratory  

South Sudan laboratory team, 2021

This is an exciting time for yellow fever (YF) diagnostics. There has been a renewed commitment by Gavi, the Vaccine Alliance to support YF diagnostic procurement until 2025, which will allow the LTWG to build on their excellent progress to date.  

As mentioned in last month’s annual highlights, here are some notable achievements by the LTWG to date: 

• Two commercial IgM serology assays (ELISA and lateral flow assay (LFA)) are currently under kit performance evaluation by the World Health Organization (WHO). 
• One commercial molecular assay kit performance assessment was completed by the WHO. 
• Regional serology and molecular testing workshops were delivered in the African region in 2021. Full details can be found here in the annual highlights 2021. 
• Molecular testing will be introduced into the African region at a national level this year. 

Upcoming news in research and development includes the development of an antigen-based LFA assay, and new YF technologies and biotechnology interests. There will also be a concerted drive to increase biobanking this year.  

In order to continue the progress made to date, we ask for your urgent attention on the following laboratory activities: 

At facility level: 

• Specimens must be collected from ALL suspect cases. 
• Quality of specimen: 
  • Serum preparation on site. 
  • 2-8° C transport and storage (for both serum and whole blood if serum can’t be separated on site). 
  • Transport to national laboratory within 48 hours of sample collection.
• Quantity of specimen 
  • Strict minimum of 1mL (ideally 2mL) of serum to be sent to national labs. 
  • ONLY if serum preparation is not possible, a strict minimum of 5mL of whole blood should be sent to the lab. 

At surveillance level: 

• Please ensure there is systematic documentation (through the standardized case identification and laboratory request forms) of the history of: 
  • Immunization 
  • Symptoms’ onset 
  • Malaria testing 

At national laboratory level (NL): 

• Ensure the continuity of reagent supplies at national laboratory level. 
• Ensure a standardized regional reference laboratory (RRL) referral algorithm is in place.
• Ensure that a strict minimum of 500uL of serum (ideally 1.5ml) is sent to the RRL for confirmation and referral testing, and biobanking. 
• Use the EYE.Ops mechanism to ensure speedy and reliable support (operational and/or financial) for international specimen referral. 

At Regional Reference Laboratory level (RRL): 

• Have clear procedures in place to communicate interruption of testing capacity. 
• Have a clear mitigation plan in place to process confirmation and referral testing in cases of interruption of testing capacity. 

If you have any questions or would like to contact LTWG, please email us at This email address is being protected from spambots. You need JavaScript enabled to view it..

Country updates   

Still from upcoming film on Taraba State YF vaccination campaign, Nigeria, 2021 - interview with community elder

Venezuela 

Venezuela first started its YF preventive mass vaccination campaigns (PMVCs) in November 2020, prioritizing the 10 states that were considered high risk from a 2019 risk assessment and targeting 100% of the population between 2 and 59 years old. By November 2021, over 80% of people were vaccinated, with five of those states reaching 100% coverage. Five states are still working towards reaching reach their goal of 100%.

Chad 

A reactive YF vaccination campaign was launched by the National Nomadic Health Program of the Ministry of Public Health in mid-January 2022, in response to an outbreak impacting Melfi and Mandoul. The campaign protected over 1.1 million people (initial coverage estimate >103%), including 15,000 nomadic people and 10,000 refugees. The campaign was approved by the International Coordinating Group for Vaccine Provision (ICG) with support from Gavi, the Vaccine Alliance.  

The Democratic Republic of the Congo 

The Bloc 3 PMVC is planned to protect approximately 13 million people in Maniema, Sankuru and Sud Kivu and aims to target ~13 million people.  

Uganda 

The introduction of yellow fever vaccine (YFV) into Uganda’s routine immunization (RI) programme is planned for March 2022. 

Sudan 

YFV was introduced into Sudan’s RI programme nationwide in July 2021. This covered all 18 of the nation’s states. Catch-up activities were also completed last year in Kassala, Gedarif, Red Sea, Northern, and River Nile. River Nile and Northern states were completed with coverage of ~90%. Remaining catch-up activities are scheduled for completion this year. 

Nigeria  

In 2021, Nigeria protected ~24.8 million people through PMVCs, with an additional 2.5 million through reactive vaccination campaigns in response to YF outbreaks. PMVCs in Ogun and Gombe states were deferred due to the timing of the vaccine’s arrival and are anticipated to take place in March 2022.  

Two films of the Nigerian vaccination campaigns will be published in next month’s newsletter. 

Ghana 

Further outbreaks are happening in the country, and a second phase of reactive vaccination campaigns has been planned for February. The activities are planned in 40 sub-districts of 7 regions. Sub-districts have been selected based on local epidemiology in Ashanti, Bono, Eastern, Greater Accra, Oti, Savannah and Upper West.   

This phase of reactive vaccination is supplementary to the previous activities which were completed in December 2021. In total, these reactive vaccination campaigns are expected to protect over 850,000 people, and have been approved by the International Coordinating Group for Vaccine Provision (ICG) with support from Gavi. 

Training  

Uganda

One-week regional combined serology (MAC-ELISA 72h), molecular (Altona RT-PCR kit) and data management (Epi Info software) workshop organized for English-speaking African countries hosted by Uganda Virus Research Institute (UVRI), Entebbe, Uganda, December 6-11, 2021. 

Publications

Epidemiological update – Americas  

In 2021, four countries in the region of the Americas (Bolivia, Brazil, Peru, Venezuela) have reported confirmed yellow fever cases. In 2020, two countries in the Region of the Americas reported confirmed cases of yellow fever (Bazil and Peru). You can read the full situation summary here.  

Research article* 

Yellow fever is an arboviral disease which is endemic to Brazil due to a sylvatic transmission cycle maintained by infected mosquito vectors, non-human primate (NHP) hosts, and humans. Despite the existence of an effective vaccine, recent sporadic YF epidemics have underscored concerns about sylvatic vector surveillance, as very little is known about their spatial distribution. Here, we model and map the environmental suitability of YF’s main vectors in Brazil, Haemagogus spp. and Sabethes spp., and use human population and NHP data to identify locations prone to transmission and spillover risk. You can read the full report here. 

*This has not been peer-reviewed by the EYE Strategy or any of its partners.