Revolutionizing Protection: The Quest for a Long-Lasting Whooping Cough Vaccine

9th December 2024 By The Global Heroes Health

Once a deadly 19th-century killer, whooping cough is experiencing a resurgence, spurring the search for a more enduring vaccine. Despite global vaccination efforts, the current solutions face limitations, prompting scientists to innovate and prepare for a healthier future.

A Persistent Threat

Whooping cough, or pertussis, caused by the Bordetella pertussis bacteria, is highly contagious and resurges in cyclical patterns. In recent years, cases have risen globally, especially following the COVID-19 pandemic. Europe, for instance, reported a sharp increase in cases in early 2024 compared to the previous year. Vaccine coverage among pregnant women, a key demographic for protection, has also declined in many regions. In the UK, vaccination rates among pregnant women dropped from 70.5% in 2019-2020 to 58.6% by 2023-2024.

The disease primarily endangers unvaccinated infants, but waning immunity from current vaccines means older children and adolescents are also increasingly affected. In Denmark and Slovenia, for example, the majority of cases are now seen in young people aged 10 to 19.

Current Vaccines: Strengths and Limitations

Vaccines against pertussis, first introduced in 1948, have significantly reduced deaths and severe cases. Modern options include whole-cell vaccines, widely used in low- and middle-income countries, and acellular vaccines, common in wealthier nations. Whole-cell vaccines are highly effective but can cause severe side effects, while acellular vaccines are safer but less durable, offering immunity that diminishes over time.

Acellular vaccines show a sharp decline in effectiveness, especially in adolescents. Studies reveal that protection drops from 72% in the first year to just 42% after four years. The need for frequent boosters complicates vaccination schedules and decreases compliance, highlighting the urgent need for longer-lasting solutions.

Innovating for the Future: Third-Generation Vaccines

Scientists are working on next-generation pertussis vaccines to address these challenges. A promising candidate is the BPZE1 vaccine, developed by Camille Locht and now under ILiAD Biotechnologies' purview. Unlike existing options, BPZE1 contains live, weakened bacteria and is administered nasally, targeting the mucosal immune system in the nose and lungs where infections begin. This approach induces robust and potentially long-lasting immunity.

Clinical trials for BPZE1 are advancing, with Phase 3 trials expected by 2025. Distribution could begin as early as 2026, offering hope for a vaccine that requires fewer doses and lasts decades.

Other Groundbreaking Approaches

Researchers like Daniela Hozbor and Kingston Mills are exploring alternative strategies, including nasal and injectable vaccines using outer-membrane vesicles. These spherical structures, derived from the bacteria itself, mimic the infection process and stimulate a strong immune response with fewer side effects. Hozbor’s team envisions vaccines that could work either independently or as adjuvants to enhance existing vaccines.

Meanwhile, Mills’ lab is testing a nasal vaccine designed to create durable immune memory. These innovations align with the emerging consensus that nasal delivery systems, which directly target respiratory immunity, could redefine pertussis prevention.

Challenges Ahead

Despite progress, significant hurdles remain. Vaccine affordability and accessibility, particularly in low-income countries, must be addressed. Additionally, vaccine hesitancy persists, fueled by misinformation and lack of public confidence. Researchers emphasize the need for transparent communication about vaccine safety and efficacy to boost acceptance.

Pharmaceutical interests also pose a dilemma. Developing a long-lasting vaccine could reduce the need for frequent booster shots, potentially conflicting with companies' profit-driven models. Finding a balance between public health priorities and commercial viability is essential.

A Brighter Future

While current vaccines remain critical for controlling pertussis, the push for longer-lasting, more effective solutions is vital. For individuals like Juliet Lautenbach, whose daughter endured prolonged suffering from whooping cough, the promise of a vaccine providing enduring protection is transformative.

"We need vaccines that adapt to evolving challenges," says Locht. With innovations like BPZE1 on the horizon, the goal of eradicating pertussis - or at least minimizing its burden - is closer than ever.