Tuberculosis DNA vaccine nasal delivery shows therapeutic promise in Johns Hopkins study

Johns Hopkins researchers are reporting an encouraging advance in the fight against tuberculosis: a DNA vaccine delivered through the nose that primes the lungs’ immune defenses and boosts the effects of antibiotic therapy. Early studies in mice and rhesus macaques show stronger, longer-lasting immune responses in the respiratory tract and improved bacterial clearance when the vaccine is paired with standard and drug-resistant TB drug regimens.

The work, published in the Journal of Clinical Investigation by investigators at Johns Hopkins Medicine and the Bloomberg School of Public Health, directly addresses a global priority. With TB still responsible for the most deaths from a single infectious disease worldwide and an estimated two billion people carrying latent infection, scientists are seeking ways to shorten long antibiotic courses and to overcome drug-tolerant bacteria that survive treatment.

What the new nasal DNA vaccine aims to do

The vaccine strategy combines two genetic elements into a single DNA construct that is administered intranasally. The goal is twofold: marshal immune cells where Mycobacterium tuberculosis first takes hold — the respiratory mucosa — and teach the immune system to recognize and eliminate bacteria that can persist through antibiotic treatment.

Key components of the vaccine

• relMtb gene: Encodes a protein that helps TB bacteria enter a low-activity, drug-tolerant state when stressed by antibiotics, low oxygen, or nutrient scarcity.
• Mip3α gene: Produces a signaling molecule that attracts immature dendritic cells, which are critical for presenting TB antigens to T cells and launching a targeted immune attack.

How intranasal delivery changes the immune response

Delivering DNA vaccine material through the nose concentrates immune activation in the airways and lungs, the very sites where TB infection and transmission occur. This localized approach aims to create a durable mucosal T-cell presence while also stimulating systemic immunity.

• By recruiting dendritic cells to the respiratory mucosa, the vaccine promotes antigen presentation to both CD4 (helper) and CD8 (killer) T cells.
• Local activation in the lungs supports formation of organized immune structures and sustained T-cell populations in the airways.
• Localized mucosal immunity may be especially effective against bacteria that hide in low-metabolic states where antibiotics alone struggle to reach them.

Evidence from animal studies: mice and primates

Researchers tested the DNA vaccine in several preclinical models to assess efficacy and durability of immune responses.

Results in mice

• When given alongside first-line TB drugs, the intranasal vaccine accelerated bacterial clearance in the lungs compared to antibiotics alone.
• The combination decreased lung inflammation and lowered the chance of relapse after treatment ended.
• Improvements were observed in both CD4 and CD8 T-cell numbers and in how dendritic cells and T cells were organized in lung tissue.

Findings in rhesus macaques

• Rhesus macaques developed measurable TB-specific immune responses in blood and airway samples after vaccination.
• Those responses lasted at least six months, indicating promising durability.
• Nonhuman primate data offer an important translational bridge toward human trials because their immune systems more closely resemble ours.

Potential role alongside drug-resistant TB therapies

Beyond combining with standard first-line antibiotics, the new vaccine also enhanced the effect of a potent regimen used against drug-resistant strains — bedaquiline, pretomanid, and linezolid. That suggests the vaccine could function as an adjunct to shorten therapy or improve outcomes for hard-to-treat infections.

• Adjunctive immunotherapy targets the surviving, drug-tolerant bacterial population that antibiotics may miss.
• By helping the immune system clear residual bacteria, a therapeutic vaccine might reduce relapse risk and the duration of multidrug courses.

Why DNA vaccines are a practical choice for TB

DNA vaccines offer several logistical advantages: they are relatively stable, can be manufactured efficiently, and are amenable to rapid modification. That makes them attractive candidates for large-scale therapeutic use if safety and efficacy are confirmed in human studies.

Advantages to public health and treatment delivery

• Potential to shorten long multidrug regimens that are difficult for patients to complete.
• Possible applicability in both drug-susceptible and drug-resistant TB settings.
• Focused mucosal immunity could reduce transmission by lowering bacterial load in the lungs and airways.

Scientific context and next steps

The research team, led by Styliani Karanika, MD, at the Johns Hopkins Center for Tuberculosis Research, designed the vaccine to direct immune activity against the bacterial persistence machinery while drawing in the antigen-presenting cells needed to teach T cells what to attack. Their published preclinical work provides a roadmap for additional safety testing and the regulatory steps required before human trials can begin.

Tuberculosis has shaped human history for millennia and remains a global health priority. New tools that pair immune-directed strategies with antibiotics could change how clinicians approach eradication of persistent infection and management of drug-resistant disease, but clinical testing will be required to determine whether the promising animal results translate to people.

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Michael Thompson

Michael Thompson is an experienced journalist covering U.S. and global news. With ten years on the front lines, he breaks down political and economic stories that matter. His precise writing and keen attention to detail help you grasp the real‑world impact of every event.