The leading cause of death among children under age 5 often begins with little more than a cough.

Followed by chills, fever, and nausea.

And then as the child’s lungs get flooded with fluid, each breath becomes a desperate gasp for air.

What I’m describing is known as pneumonia, an acute respiratory condition that kills over 670,000 children every year.

And here’s a sentence I find difficult to write: Nearly all those deaths could have been prevented.

Access to vaccines, diagnostic tools, and treatments can protect children from deadly pneumonia. But these solutions are often not available or accessible in many low- and middle-income countries, where children are at greatest risk.

Even as child deaths have declined by nearly 50 percent over the past two decades, deaths from pneumonia have remained stubbornly high.

That’s why our foundation is focused on improving access to and development of vaccines that can prevent it.

One of the most exciting areas of progress is the development of a powerful new vaccine designed to protect children against pneumococcal bacteria, which is the leading cause of deadly pneumonia. Of the 670,000 children who die from pneumonia ever year, pneumococcal pneumonia is responsible for killing 400,000 of them.

What makes this new vaccine unique is that it is designed to protect against 25 different types of pneumococcal bacteria, more than any other available vaccine. Existing pneumococcal vaccines protect against about half as many types of pneumococcal pneumonia. To address the remaining deaths from pneumococcal pneumonia, vaccines that offer broader protection like this new vaccine will be needed.

The vaccine, called IVT-PCV25, is being developed by Inventprise, a small biotechnology company based outside Seattle. I recently took a tour of their new vaccine manufacturing plant and got an update on their progress.

It was amazing to see the innovations underway at Inventprise. Making a vaccine that is effectively 25 vaccines in one is an extremely complex challenge. Past efforts to add more strains of pneumococcal bacteria to vaccines using conventional technologies have resulted in vaccines that didn’t produce a strong enough immune response. Inventprise intends to overcome this obstacle with its proprietary vaccine technology that is designed to guard against many types of pneumococcal bacteria without any decline in protection.

Inventprise’s new factory, supported by a grant from our foundation, is a highly automated facility that marks an important step forward in Inventprise’s development of the vaccine. Clinical trials of the vaccine are expected to begin later this year.