Nurses in countries from Sierra Leone to Cameroon are packing a new vaccine into the coolers they tote to villages for immunization clinics: a shot to protect against malaria, one of the deadliest diseases for children. Babies and toddlers in eight countries in the region recently started to get the vaccine as part of their routine childhood shots. Seven other African countries are eagerly awaiting its arrival. This is a milestone in global health.

But it’s also a cautionary tale about a system that is ill equipped to deliver critical tools to the people who need them most. It took decades and at least a billion dollars to reach this point. Even now, only a fraction of the children whose lives are at risk will get the vaccine this year, or next year, or the year after. It’s been clear for some time what went wrong, but almost none of those issues have been fixed. That means that the next desperately needed vaccine stands every chance of running into those same problems.

Take, for example, a new vaccine for tuberculosis that started clinical trials a few months ago. If it works as well as hoped, it could save at least a million lives a year. We’ll know by 2028 if it stops tuberculosis infections. But if it follows the same trajectory, it will be at least 2038 before it’s shipped to clinics.

‘Children are receiving the vaccine, and for that, I am the happiest man in the world. But on the other hand, I cannot avoid being dismayed at this inexcusably long delay.’ — Dr. Joe Cohen, co-inventor of the first malaria vaccine

The U.S. Army started work on a malaria vaccine back in the 1980s, hoping to protect soldiers deployed to the tropics. The first vaccine for malaria received major regulatory approval in 2015. It didn’t become part of vaccination programs in Africa until 2024. What if it had come faster? What if the shots had arrived 9 years ago? 143,000. That’s how many children’s deaths could have been averted.