Whooping cough — once a feared 19th-century killer — is staging a worrying comeback. With the specter of waning vaccine protection hovering over us, the race is on for a more enduring solution. But what exactly is driving this resurgence, and how close are we to finding a vaccine that stands the test of time? Let’s dive into this unfolding saga.

What’s Behind the Return of Whooping Cough?

Whooping cough, or pertussis, is more than a relic of the past. It’s a highly contagious respiratory disease caused by the Bordetella pertussis bacterium. Despite modern medical advancements, pertussis cyclically resurfaces, and after a brief hiatus during the Covid-19 pandemic, cases are on the rise again.

Picture this: a bustling office space, filled with unsuspecting workers. In walks a colleague with a persistent cough, unknowingly spreading the pertussis bacteria. Within an hour, 90% of susceptible individuals in that room might contract the disease. This scenario highlights the critical need for a vaccine that doesn’t just halt symptoms but effectively prevents infection.

How Effective Are Our Current Vaccines?

The world of pertussis vaccines is a tale of two systems. First-generation whole-cell vaccines, still in use in many low and middle-income countries, are cheaper and highly effective but can cause severe side effects. Meanwhile, wealthier countries rely on second-generation acellular vaccines, which are safer but offer shorter-lived immunity because they target only a few antigens compared to the whole-cell approach.

Camille Locht, a leading researcher at Inserm, explains that while acellular vaccines are adept at reducing mortality, they don’t prevent infection entirely. “The immunity is short-lived, which is why we see a decline in effectiveness over time,” he notes, pointing to studies that show a drop in vaccine effectiveness from 98% in the first year to 42% after four years in older children.

Why Do We Need a Third-Generation Vaccine?

Given the limitations of current vaccines, researchers like Locht are pioneering third-generation solutions using live, attenuated bacteria. These novel vaccines mimic natural infection more closely, potentially inducing a stronger and longer-lasting immunity. The BPZE1 vaccine, currently advancing towards phase 3 clinical trials, could reach the market by 2026 or 2027. This nasal spray vaccine promises not only to be longer-lasting but also safer, with minimal side effects.

Kingston Mills, from Trinity College Dublin, echoes this optimism, emphasizing the potential of nasal vaccines to generate robust mucosal immune responses right where the infection starts — in the nasal cavity and lungs. “These vaccines hold the promise of being the future for pertussis prevention,” he asserts.

What Challenges Lie Ahead?

Despite promising developments, challenges remain. Ethical considerations prevent immediate testing of live bacterial vaccines on young children, slowing the research pipeline. Additionally, vaccine hesitancy poses a barrier to widespread adoption. As Daniela Hozbor from Argentina highlights, high vaccination coverage is crucial given pertussis’s contagious nature.

Cost is another hurdle. Locht is optimistic that the BPZE1 vaccine will be economical to produce, yet the broader economic implications remain complex. Will pharmaceutical companies embrace a one-dose vaccine model when the current system mandates multiple boosters?

Where Do We Go From Here?

As we stand on the cusp of a new era in pertussis prevention, the hope is to create vaccines that not only protect but do so sustainably and universally. For families like Juliet Lautenbach’s, who have witnessed the harrowing effects of whooping cough firsthand, the promise of a long-lasting vaccine is nothing short of transformative.

In the end, while our current vaccines have been crucial in reducing whooping cough mortality, the journey towards an improved, enduring vaccine continues. With dedicated research and global cooperation, a future where whooping cough is a fully preventable disease might be just around the corner.

• —

If this story piqued your interest, consider subscribing to The Essential List newsletter for more insightful features and must-read news delivered straight to your inbox.