Vaccine News

According to the Pan American Health Organization (PAHO) Situation Report No. 12, the dengue fever outbreak in 2024 is setting unfortunate records. 

Twenty-two countries and territories in the Region of the Americas reported the circulation of dengue serotypes. Brazil, Costa Rica, Guatemala, Honduras, Mexico, and Panama report the simultaneous circulation of all four dengue subtypes.

Between epidemiological weeks 1 and 11 of 2024, 3,665,589 suspected cases of dengue were reported in the Americas.

This figure represents an increase of 286% compared to the same period in 2023.

In the Southern Cone subregion. 410,296 new suspected dengue cases were reported last week, representing an increase of 342% compared to the same week in 2023.

While Brazil has reported the most dengue cases, Argentina presented a 67% increase in cases compared to the four previous epidemiological weeks.

The Caribbean is also reporting a significant increase in dengue cases this year.

As of April 11, 2024, there is good news regarding dengue protection. Both approved dengue vaccines are available in the Americas.

The second-generation dengue vaccine QDENGA® is available in Argentina, Brazil, and other countries, but not the United States.

Recent reports indicate that the yellow fever (YF) virus, which is transmitted by mosquitoes, will continue to have a severe impact on human health in 2024.

According to the U.K.'s Travel Health Pro reporting on April 4, 2024, in South America, there have been seven confirmed cases of YF, out of which four have been fatal, including three in Colombia and two in Guyana and Peru, respectively.

In Brazil, six cases of yellow fever, including four deaths, have been confirmed this year in Minas Gerais, Espírito Santo, and São Paulo.

While vaccination for YF is one of the most successful public health interventions to prevent the disease, most international travelers remain unprotected.

Public health leaders in the United Kingdom, the United States, and the World Health Organization recommend pre-trip yellow fever vaccination for all travelers aged nine months and above who are visiting areas with a risk of yellow fever unless the vaccine is not advised for medical reasons.

In 2017, the U.S. Centers for Disease Control and Prevention expanded its yellow fever vaccine recommendations for travelers to Brazil because of a large outbreak in multiple states.

As of April 11, 2024, the YF-VAX® vaccine is offered at certified clinics and pharmacies in the U.S. Internationally, the Stamaril vaccine is offered in various countries.

These vaccine providers also offer travel-related vaccination services for diseases such as dengue, influenza, measles, and polio.

As the world battles the resurgence of measles outbreaks, most vaccination campaigns are reactive.

According to an announcement by Ginkgo Bioworks, an AI-enabled measles forecasting model may soon empower proactive public health measures, such as immunization campaigns.

Announced today, Ginkgo's epidemiological modeling experts and Northeastern University researchers were awarded a grant from the Bill & Melinda Gates Foundation to develop a forecasting model to assess the risk of measles outbreaks and inform decision-making for timely interventions.

This innovative model will draw upon traditional and non-traditional data, including public health reports, travel patterns, economic activity, and other factors, and utilize AI approaches such as machine learning and deep learning to structure and analyze a multitude of data sources to produce actionable insights.

Matt McKnight, General Manager for Biosecurity at Ginkgo Bioworks, commented in a press release on April 10, 2024, "If we wait until large pockets of measles show up in hospital systems to launch public health responses, we are missing a critical window to act and slow the spread of this debilitating and highly contagious disease."

"Modern data and AI tools can shift the biosecurity and public health paradigm from reactive to proactive by helping global health leaders make more timely, effective decisions to prevent outbreaks from happening in the first place."

Measles is a highly contagious and often severe disease that most commonly affects children. While the widespread availability of measles vaccines has dramatically reduced the disease burden over the past several decades, cases are on the rise in the U.S. in 2024.

The majority of measles cases imported into the United States occur in unvaccinated residents who become infected during international travel, says the U.S. CDC.

For example, a substantive, ongoing measles outbreak has occurred in Chicago, Illinois, over the past two months.

Transgene and NEC Corporation today announced that new data will be presented on TG4050, an individualized neoantigen cancer vaccine, at the American Association for Cancer Research (AACR) Annual Meeting.

TG4050 is being evaluated in a randomized multicenter Phase I/II trial as a single agent in the adjuvant treatment of HPV-negative head and neck cancers. 

Key findings of the poster presentation obtained in the Phase I part of the trial (NCT04183166) include, but are not limited to, the following:

All 16 patients who received TG4050 are disease-free after a median 18.6-month follow-up. Out of the 16 patients in the control observation arm, three patients have relapsed. For this head and neck cancer patient population and with the current standard of care (chemoradiotherapy), approximately 40% of patients are expected to relapse within 24 months following surgery and adjuvant therapy. Also, the tumor immune contexture, expression of immune factors, mutational burden, and tumor infiltrates are associated with challenging prognoses.

Specific cellular immune responses were detected in the 16/17 patients who received TG4050 (16 patients from the treatment arm and one from the observation arm treated after relapse) using stringent testing conditions.

TG4050 induced persistent immune responses against multiple targets in several patients. T-cell responses were maintained beyond 211 days (7 months) after the initiation of the treatment. 

Dr Oliver Lantz, Head of the clinical immunology laboratory at Institut Curie, commented in the April 9, 2024, press release, "The immunological data generated by TG4050 demonstrate a robust and specific cellular immune response, even under stringent measurement criteria."

"The diversity, depth, and duration of these responses were most certainly a key factor in preventing relapse in the patients treated with TG4050."

According to statements, Transgene and NEC are preparing a randomized Phase II extension of this trial, slated to start in the second quarter of 2024.

The U.S. CDC says cancers of the head and neck include cancers that start in several places in the head and throat. Cancer is a disease in which cells of the body grow out of control.

About 70% of cancers in the oropharynx (which includes the tonsils, soft palate, and base of the tongue) are linked to human papillomavirus, a common sexually transmitted virus, says the CDC.

Pfizer Inc. today reported encouraging top-line data regarding the safety and immunogenicity of its ABRYSVO® vaccine from an ongoing Phase 3 clinical trial.

The study (NCT05842967) has been evaluating the effectiveness of a single dose of the vaccine compared to a placebo in adults between the ages of 18 and 59 who are at risk of developing severe lower respiratory tract disease associated with respiratory syncytial virus (RSV). 

On April 8, 2024, Pfizer confirmed the MONeT study achieved its co-primary immunogenicity endpoints and primary safety endpoint:

• Participants demonstrated RSV-A and RSV-B subgroup neutralizing responses non-inferior to the response seen in the Phase 3 RENOIR study of ABRYSVO in more than 34,000 adults aged 60 or older where vaccine efficacy was previously demonstrated.
• Participants also achieved at least a four-fold increase in serum neutralizing titers for RSV-A and RSV-B one month after receiving ABRYSVO compared to pre-vaccination.
• During the trial, ABRYSVO was well-tolerated, and safety findings were consistent with those from previous investigations of ABRYSVO in other populations.

Pfizer stated it intends to submit these data to regulatory agencies and request expansion of the age group from the current indication to 18 years of age and older.

This is an essential study since no RSV vaccines were approved for adults in this age group during the 2023-2024 RSV season.

“These encouraging results provide evidence that ABRYSVO can help protect adults with increased risk against RSV-associated illness,” said Annaliesa Anderson, Ph.D., Senior Vice President and Head, Vaccine Research and Development, Pfizer, in a press release.

“We are excited to address a significant unmet need, pending regulatory authority approval, as ABRYSVO has the potential to become the first and only RSV vaccine for adults 18 years and older.”

As of April 5, 2024, RSV vaccines have been approved in Canada, Europe, Japan, the United States, and the United Kingdom.

The U.S. CDC estimates the percentage of adults 60+ vaccinated this season was 23.6%. And RSVVaxView reported that the overall RSV vaccination rate among pregnant women was about 18%.

Clover Biopharmaceuticals, Ltd. today announced positive preliminary immunogenicity and safety data in the initial young adult cohort from its Phase I trial evaluating SCB-1019, a bivalent RSV prefusion-stabilized F (PreF)-Trimer subunit vaccine candidate.

Clover's preliminary immunogenicity data across RSV-A and RSV-B neutralization appear to be in line or potentially favorable compared to other protein subunit RSV PreF vaccines.

These data support Clover's bivalent RSV-A/B approach, given that other monovalent RSV-A vaccines have previously observed lower immune responses and/or efficacy against RSV-B.

The results also confirm that Clover's PreF antigens in SCB-1019 are in the stabilized prefusion and trimeric form, further supported by exploratory immunogenicity results demonstrating significant increases in Site Ø neutralizing antibody-competitive titers.

Additionally, the SCB-1019 vaccination did not observe any notable safety or reactogenicity issues in this initial young adult cohort, enabling the planned enrollment of older adults to proceed in the Phase I clinical trial.

"We are encouraged by the progress and positive preliminary Phase I results for our bivalent RSV PreF vaccine candidate utilizing our validated Trimer-Tag platform, demonstrating broad and significant neutralizing antibody responses against both RSV-A and RSV-B," said Joshua Liang, Chief Executive Officer & Board Director of Clover, in a press release on April 8, 2024.

"As the first RSV PreF vaccine candidate developed in China to enter the clinical trial stage and now the first to generate clinical data, we look forward to the additional Phase I clinical data in our initial target older adult population in the second half of 2024 as planned."

As of April 2024, first-generation RSV vaccines have been approved in Canada, Europe, Japan, the United States, and the United Kingdom. The U.S. CDC estimated the percentage of adults 60+ was 23.6% (22.8-24.5). 

A multi-month chikungunya virus outbreak continues impacting the residents of Timor-Leste (East Timor). As of late March 2024, 195 chikungunya cases have been reported in Timor-Leste.

The U.S. CDC reissued a Level 2 - Practice Enhanced Precautions Travel Health Advisory on April 5, 2024, to alert international travelers. Data sources indicate tourist arrivals in East Timor increased to 3,718 in the first quarter of 2022.

Additionally, neighboring countries, such as Thailand (139), Pakistan (26), and Malaysia (6), reported chikungunya cases in 2024.

The Chikungunya virus causes this mosquito-transmitted disease. Most people infected develop some symptoms, but related fatalities are rare.

However, people at risk for more severe disease include newborns infected around the time of birth, older adults, and people with medical conditions such as high blood pressure, diabetes, or heart disease.

According to the CDC, if you are a pregnant woman, reconsider traveling to Timor-Leste.

There is no specific treatment for chikungunya, but the CDC's Advisory Committee on Immunization Practices recommends the newly approved IXCHIQ® chikungunya vaccine for some travelers.

Jeri Beales, MSN RN with Destination Health Travel Clinic near Boston, MA, offered these comments, "With the CDC's new guidance for the IXCHIQ vaccine, all adults traveling to Timor-Leste should consider vaccination because infection with the virus has been linked to prolonged and severe fatigue and joint pain which can last months or years."

"The immunization experts at the CDC also recommend the IXCHIQ vaccine for some travelers going to countries that have reported cases in the previous five years."

"Travelers staying six months or longer are at the highest risk for infection, but vaccination can also be considered for those 65 years and older because they are more likely to have severe complications with an infection. If you plan to travel this summer, talk to your doctor or local travel health clinic to see if the IXCHIQ vaccine is recommended."

"Countries with outbreaks in the past five years span the globe, including regions of Central and South America, Africa, and Asia.  

Timor-Leste is also experiencing dengue outbreaks and a resurgence of the Zika virus in the Ermera municipality in 2024.

As of late February 2024, local media reported 27 Zika cases and 460 dengue cases.