Vaccine News

A vaccine to prevent chlamydia infections is considered an important measure to control sexually transmitted and ocular infections.

Chlamydia trachomatis is the most common sexually transmitted bacterial infection worldwide, says the U.S. CDC.

As of April 2024, there is no vaccine against the major global pathogen Chlamydia trachomatis; its different serovars cause trachoma in the eye or chlamydia in the genital tract. 

However, significant research and investment have been made towards developing a chlamydial vaccine, but it has been quite some time since a successful phase 1 trial, commented Wilhelmina Huston, with the School of Life Sciences, University of Technology, Sydney, Australia, in an editorial published by The Lancet.

According to results from a phase 1 study (CHLM-02), Statens Serum Institut's CTH522, adjuvanted with CAF01 or CAF09b, is safe and immunogenic. 85 μg CTH522-CAF01 induces robust serum IgG binding titers.

Intradermal vaccination conferred systemic IgG neutralization breadth, and topical ocular administration increased ocular IgA formation. By day 42, the active groups had a 100% four-fold seroconversion rate, while the placebo group had no seroconversion.

The participants were healthy men and non-pregnant women aged 18–45 years without pre-existing C trachomatis genital infection.

Participants were randomly assigned (1:1:1:1:1) to each of the groups A–E, which received an investigational medicinal product, and group F received a placebo only.

Two liposomal adjuvants, CAF01 and CAF09b, were compared.

Serum IgG anti-CTH522 titers were higher after 85 μg CTH522-CAF01 than 15 μg, although not significantly, with no difference after three injections of 85 μg CTH522-CAF01 compared with CTH522-CAF09b (group E).

Intradermal CTH522 (group C) induced high titers of serum IgG anti-CTH522 neutralizing antibodies against serovars B (trachoma) and D (urogenital).

Topical ocular CTH522 (group B) at days 28 and 112 induced higher total ocular IgA compared with baseline (p<0·001).

Participants in all active vaccine groups, particularly groups B and E, developed cell-mediated immune responses against CTH522.

These findings published by The Lancet indicate the CTH522 vaccine candidate's regimens against ocular trachoma and urogenital chlamydia for testing in phase 2 clinical trials.

This phase 1, double-blind, randomized, placebo-controlled trial was conducted at the National Institute for Health Research Imperial Clinical Research Facility in the U.K.

As of April 17, 2024, the U.S. FDA, the U.K., and the European Medicines Agency have not approved a vaccine to prevent chlamydia infections.

However, Sanofi's multi-antigen chlamydia vaccine candidate is planning a Phase 1/2 study in 2024.

A global biopharmaceutical company developing a new class of transformative medicines based on messenger ribonucleic acid (“mRNA”) announced today a co-development and licensing agreement with The University of Texas MD Anderson Cancer Center to develop novel mRNA-based cancer vaccines.

CureVac N.V. stated in a press release on April 16, 2024, that the collaboration creates strong synergies between its unique end-to-end capabilities for cancer antigen discovery, mRNA design, and manufacturing and MD Anderson’s expertise in cancer antigen discovery and validation, translational drug development, and clinical research.

The collaboration will focus on developing differentiated cancer vaccine candidates in selected hematological and solid tumor indications with high unmet medical need.

Following the selection of the most promising validated vaccine candidates and the completion of Investigational New Drug approvals, Houston, Texas-based MD Anderson will be responsible for conducting initial Phase 1/2 studies in appropriate clinical indications.

“We look forward to collaborating with the team at MD Anderson to push the boundaries of mRNA technology and develop impactful therapeutic options for patients in need,” commented Dr. Alexander Zehnder, Chief Executive Officer of CureVac.

“By combining our respective expertise, we believe we can go further and faster in developing novel, off-the-shelf, mRNA-based cancer vaccines that have the potential to improve patient outcomes significantly.”

Both parties will contribute to identifying differentiated cancer antigens based on whole genome sequencing, combined with long- and short-read RNA sequencing and cutting-edge bioinformatics. 

Despite the expenditure of over $3 billion to fight malaria outbreaks since 2021, the world still witnessed an estimated 600,000 malaria deaths and 247 million clinical malaria cases.

To address malaria outbreaks in Africa, new vaccines have recently been deployed.

The Mosquirix™ RTS,S/AS01E malaria vaccine (RTS,S) was introduced in 2019 by national immunization programs in Ghana, Kenya, and Malawi. Researchers aimed to address questions about feasibility and impact, as well as assess safety signals observed during the phase 3 clinical trial.

In a prospective evaluation published by The Lancet on April 4, 2024, the three primary doses were effectively deployed during the first two years of implementation of RTS,S.

There was no evidence of the safety signals that had been observed in the phase 3 trial, and the introduction of the vaccine was associated with substantial reductions in hospital admissions with severe malaria.

This evaluation continues to assess the impact of four doses of Mosquirix.

This study was funded by Gavi, the Vaccine Alliance, the Global Fund to Fight AIDS, Tuberculosis, and Malaria, and Unitaid. No industry conflicts were disclosed.

In addition to RTS,S, the R21/Matrix-M™ malaria vaccine, co-produced by scientists at the University of Oxford, Novavax AB, and Novavax Inc., has been offered in Africa in 2024.

As of April 2024, the U.S. Food and Drug Administration had not approved either malaria vaccine.

According to the latest weekly update by the Global Polio Eradication Initiative (GPEI), Afghanistan reported its second wild poliovirus type 1 (WPV1) case of 2024.

This polio patient is from Nuristan province in the eastern part of the country.

Five WPV1-positive environmental samples were reported: four in Nangarhar and one in Kandahar.

As of April 14, 2024, Afghanistan is one of the two countries in the Middle East where WPV1 is still endemic.

The total number of WPV1 cases reported in 2023 remains six.

During 2024, various countries deployed the type 2 novel oral polio (nOPV2) vaccine produced by Indonesia's Biofarma.

This oral polio vaccine (OPV) has been 'triple-locked' using genetic engineering to prevent it from becoming harmful and producing a gut reaction. As a result, nOPV2 is reported to be more genetically stable than approved OPVs, with a lower risk of reversion to neurovirulence and less likely to mutate and cause paralysis.

Over the past two years, about 1.1. billion nOPV2 vaccines have been administrated worldwide. The GPEI says international travelers should speak with a healthcare provider about their polio vaccine options, including booster doses.

The inactivated polio vaccine is offered in the United States at various clinics and pharmacies.

Nationally, weekly flu hospital admissions have been decreasing since January 2024, but small outbreaks continued to be reported in April 2024.

On April 12, 2024, the U.S. Centers for Disease Control and Prevention (CDC) reported outpatient respiratory illness declined and is below baseline for the first time since late October 2023, while HHS regions 1, 5, and 7 remain above their region-specific baselines.

From a local perspective, the Walgreens Flu Index™ - Week Ending April 6, 2024, identified these ten Designated Market Areas with Flu Activity:

1. Omaha, Neb.
2. Lincoln & Hastings-Kearney, Neb.
3. El Paso, Texas (Las Cruces, N.M.)
4. Davenport, Iowa-Rock Island-Moline, Ill.
5. Lansing, Mich.
6. Oklahoma City, Okla.
7. Columbus-Tupelo-West Point-Houston, Miss.
8. Ft. Smith-Fayetteville-Springdale-Rogers, Ark.
9. Harlingen-Weslaco-Brownsville-McAllen, Texas
10. Knoxville, Tenn.

The CDC's Weekly U.S. Influenza Surveillance Report also confirmed that five influenza-associated pediatric deaths occurring during the 2023-2024 season were reported to the CDC during Week 14, bringing the season total to 138 pediatric deaths.

Furthermore, the CDC recommends people speak with a healthcare provider about late-season flu shot options. Various egg, cell, and nasal-based influenza vaccines remain available at community pharmacies in the U.S.

Note: The Walgreens Flu Index displays information regarding flu activity compiled using retail prescription data for antiviral medications used to treat influenza.

Costa Rica's Ministry of Health (MOH) and the Caja Costarricense del Seguro Social have begun investigating a potential outbreak of Bordetella pertussis (whooping cough) in the district of Tibas, located north of San Jose.

This is the same area in Costa Rica where the MOH has reported chikungunya, dengue, malaria, and Zika cases in 2024.

As of April 11, 2024, given the contagious nature of whooping cough and its severity in children and unvaccinated populations, the U.S. Embassy urges heightened awareness and vaccination verification for U.S. citizens in Costa Rica.

Before visiting Costa Rica in April 2024, the U.S. CDC advises international travelers to speak with a travel vaccine expert regarding their options one month ahead of departure.

In the Boston, Massachusetts, area, travel vaccination services are offered at Destination Health Travel Clinic.

The latest report on measles cases in England shows a steady increase in numbers and a shift in geographical distribution.

According to the April 11, 2024 update from the U.K. Health Security Agency (UKHSA), 89 laboratory-confirmed cases have occurred in the past week, bringing the total number of confirmed cases since October 2023 to 1,023.

While the outbreak in the West Midlands initially caused the surge in measles cases, the latest data reveals that London now has the highest number of newly confirmed cases.

There have been 195 measles cases in the last month, 35% of which (69 cases) were reported in London and 32% (62 cases) in the West Midlands.

In a press release, Dr. Rob Verrecchia, UKHSA Health Protection Consultant, said, "We are continuing to see measles cases right across the country, with cases particularly high in London and the West Midlands."

"Measles is completely preventable with vaccination, but many thousands of children around the country are still not fully vaccinated and are at risk of serious illness or life-long complications."

England is not alone in the measles outbreak of 2024. 

The U.S. CDC has identified measles outbreaks in 49 countries over the past year.

Additionally, the CDC recommends international travelers be fully immunized against measles. In the U.S., measles vaccines are available in clinics and community pharmacies in 2024.