Scientists at Johns Hopkins have built a new DNA vaccine that is sprayed into the nose. The vaccine aims to teach the body’s defenses to find and kill stubborn TB bacteria that can hide from medicines.
Why Tuberculosis Is Still a Problem
TB has been hurting people for thousands of years. About one‑quarter of the world’s population carries the infection without feeling sick. In 2024 more than ten million people got sick with TB and 1.2 million died.
Current drug treatments are long and hard to finish. Some TB germs become resistant to medicines, making the disease even tougher.
How the New Nasal Vaccine Works
The vaccine mixes two genes, relMtb and Mip3α. The first gene, relMtb, helps TB germs survive harsh conditions, such as when antibiotics are present. When the two genes are joined, they send a signal that draws immature dendritic cells to the site.
Dendritic cells act like messengers. They pick up pieces of the TB bug and show them to T‑cells, which then launch a targeted attack.
Giving the vaccine through the nose puts it right where TB first enters the lungs. This creates strong, lasting immune protection both in the airway lining and throughout the body.
What Animal Tests Showed
In mice, the nose‑sprayed vaccine attracted more dendritic cells and organized them with T‑cells inside the lungs. It sparked long‑lasting responses from helper (CD4) and killer (CD8) T‑cells.
Rhesus macaques also made TB‑specific immune signals in their blood and lungs after receiving the vaccine. The immune activity lasted at least six months, suggesting the protection could be durable.
The primate study only measured immune responses; it did not expose the animals to real TB infection. More work is needed before testing in people.
Future Possibilities
The researchers hope the vaccine can be used together with antibiotics to clear the hard‑to‑kill “persister” TB germs. DNA vaccines are stable and can be made quickly, which could help bring the treatment to patients faster.
Funding for this work came from several National Institutes of Health grants and support from foundations and university awards.