Take on Typhoid April Newsletter

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In this issue:

Data from India make a compelling case for TCV introduction

Data from the Surveillance for Enteric Fever in India (SEFI) project, measuring typhoid burden, were published in the New England Journal of Medicine. India has long been considered to have one of the world’s highest burdens of typhoid and the study data show even greater burden than previously published estimates. The incidence of blood culture-confirmed typhoid in children in three urban centers ranged from 576 per 100,000 child-years in Delhi to 1,173 per 100,000 in Vellore. As noted in the publication and a corresponding editorial, these results suggest the single dose typhoid conjugate vaccine (TCV) could have a major impact on improving child health by reducing typhoid disease and are a highly cost-effective intervention. Earlier this year, the Government of India, in partnership with Gavi, the Vaccine Alliance, announced plans to introduce TCV nationwide.

A public sector TCV campaign in Navi Mumbai, India, demonstrated that TCV is safe and highly effective in preventing typhoid at the community level. Further, TCV delivery costs are similar to those of other routine childhood immunizations. These are useful data to help guide decision-making.

Tracking local and global drug-resistant typhoid transmission

The rise in drug-resistant typhoid in endemic countries is a major concern for prevention and control efforts. Recent publications highlight data on the spread and evolution of drug-resistant typhoid, providing important data for decision-makers as they consider prevention efforts in their countries. The Global Typhoid Genomics Consortium recently published an analysis of 13,000 typhoid samples from 111 countries, showing that drug-resistance is becoming more common and problematic. These data highlight the urgent need to track the emergence and spread of drug-resistant typhoid to help inform TCV implementation to reduce disease transmission and antibiotic use.

While understanding the global drug-resistant typhoid landscape is important, a recent study found that drug-resistant typhoid is mostly being spread within a community. Data from Bangladesh, Malawi, and Nepal showed that the vast majority of drug-resistant typhoid cases at all three sites were caused by local strains. These results support the hypothesis that interrupting transmission through TCV introduction in children would not only protect kids but may also help reduce drug-resistant typhoid infections across a country’s entire population.

TCVs are cost-effective across models and settings

Two recent modeling analyses confirm TCVs are cost-effective. The first compared multiple health economics model predictions of TCV impact and cost-effectiveness in high-risk settings. The models predicted considerable reductions in typhoid incidence following vaccine introduction and that routine vaccination plus a one-time catch-up campaign was likely to be the most impactful and cost-effective strategy.

A second analysis modeled TCV introduction in different outbreak scenarios. The preferred strategy–from a cost-effectiveness standpoint–was to introduce TCVs before the outbreak, if an outbreak is anticipated within 10 years (as measured by potential risk for an outbreak). This analysis found that if delays in recognizing and responding to the outbreak persist for more than 6 months, introduction of preventative routine immunization with TCVs along with a catch-up campaign is the most cost-effective strategy.

13th International Conference on Typhoid & Other Invasive Salmonelloses

Submissions for abstracts, symposia, and workshops are open now through June 16! Don’t miss a chance to share knowledge with the leading voices in typhoid, paratyphoid, and Salmonella.

Building a bridge between research and implementation on national, regional, and global scales, the 13th International Conference will invigorate a united response against typhoid and other invasive salmonelloses.

The theme for this year’s conference is Catalyzing Change: The Urgency of Expanding Impact-Driven Solutions, and researchers and advocates of all backgrounds are invited to contribute.

For more information, click here. Have questions or need assistance? Contact CaT@Sabin.org.

Highlighting TCV during World Immunization Week

During this year’s World Immunization Week—celebrated April 24 to 30—we come together to focus on “The Big Catch-Up,” an effort to restore essential immunization coverage to at least 2019 (pre-pandemic) levels and strengthen primary health care to deliver immunization to the millions of children who missed routine vaccinations during the past three years. Introducing new vaccines, such as TCV, is one opportunity for countries to reach children with new and routine vaccines and strengthen their immunization systems. TCV introduction is an opportunity for integrated campaigns to reach missed children with additional routine antigens; TCV is proven safe and effective when co-administered with measles-rubella, polio, meningococcal A, yellow fever, and human papillomavirus vaccines. Funding for campaigns provides resources to bolster immunization and cold chain systems. Read more about TCV’s role in the Big Catch Up.

Superbugs and you

Tune into Vaccines and the Vulnerable: The Race to End Typhoid to hear about the impact of vaccination on typhoid. Farah Qamar, Kathy Neuzil, Denise Garrett, and Cal MacLennan discuss typhoid, transmission, diagnostics, history of vaccines, outbreaks, growing resistance, climate change, cost of illness, and much, much, more. Despite the challenges, we have tools—such as vaccines—to take on typhoid.

Farah Qamar awarded Tamgha-e-Imtiaz (Medal of Excellence)

President of Pakistan recognized Dr. Farah Qamar for her long-term achievements and contributions to public health. Her research on extensively drug-resistant typhoid was instrumental to the introduction of TCV in Pakistan. Dr. Qamar’s work in pediatric infectious diseases has helped reduce childhood mortality through policy and capacity-building. We celebrate Dr. Qamar’s great achievements that include efforts to take on typhoid.

Outbreak reports

The Philippines Department of Health has reported 3,285 typhoid cases from January 1 to March 18, an increase of 101 percent compared to the same period last year.

Since the beginning of 2023, a total of 1,800 suspected typhoid cases, including 12 deaths, have been notified in the Panzi health zone in Kwango province, Democratic Republic of Congo.

 

Scientific publications

Blogs
Burden of typhoid and paratyphoid fever in India

Enteric fever—tools for prevention

Efficacy of typhoid conjugate vaccine: Final analysis of a four-year, randomised controlled trial in Malawian children

Immune responses in children after vaccination with a typhoid Vi-tetanus toxoid conjugate vaccine in Bangladesh

Programmatic effectiveness of a pediatric typhoid conjugate vaccine campaign in Navi Mumbai, India

Cost-effectiveness analysis of typhoid conjugate vaccines in an outbreak setting: A modeling study

Delivery cost of the first public sector introduction of typhoid conjugate vaccine in Navi Mumbai, India

A Phase II/III, multicenter, observer-blinded, randomized, non-inferiority and safety, study of typhoid conjugate vaccine (EuTCV) compared to Typbar-TCV® in healthy 6 Months-45 years aged participants

Identification of multiple variant extensively drug-resistant typhoid infections across Pakistan

Visit our publications page for more recent research

Typhoid conjugate vaccines can be a big part of the big catch-up!

The need for typhoid conjugate vaccines in India

Typhoid conjugate vaccines are effective at the community level

Transmission of drug-resistant typhoid is more local than global

The models confirm: TCVs are cost effective

Water, sanitation, and hygiene resources to accelerate change

TCVs are cost-effective in outbreak settings

Celebrating women in typhoid

Previous posts available on the blog