Vaccines have long stood as the frontline defense against some of the world’s deadliest infectious diseases, but new research suggests that the future of immunization could look quite different—and a lot less intimidating for those who fear needles. In a pair of groundbreaking studies published in August 2025, scientists are exploring two innovative approaches: a next-generation pneumococcal vaccine designed to protect infants against more strains than ever before, and a needle-free, floss-based vaccine delivery system that could one day revolutionize how we receive protection against viruses like influenza.
The first of these efforts, led by the Murdoch Children’s Research Institute (MCRI) in Melbourne, is currently underway as part of an ambitious international trial. According to MCRI, the study is testing a new pneumococcal vaccine that covers 21 strains of the bacteria—an impressive leap from the 13 strains included in Australia’s current National Immunisation Program (NIP). Pneumococcal disease, which can cause pneumonia, sinusitis, and meningitis, remains a significant threat to young children, particularly those under two years old.
“Having a vaccine that could offer broader protection is crucial to protecting more children from severe preventable infections and death,” said Professor Margie Danchin of MCRI, in comments shared by the institute. She explained that pneumococcal infections are caused by a common bacteria that lives in the nose and throat, sometimes leading to serious complications such as pneumonia, bloodstream infections, or even infections of the brain lining. The stakes are high: in 2024 alone, Victoria recorded 602 cases of invasive pneumococcal disease, with 373 of those affecting children aged zero to four.
The new vaccine’s promise lies in its expanded coverage. “Our trial of this new pneumococcal vaccine, which has shown good results in earlier studies and will protect against 21 strains, has the potential to save more lives,” Danchin added. However, she emphasized that rigorous research is essential before any new vaccine is introduced into the national schedule. “We always need to ensure that children and families are being offered the best protection against severe disease with new and improved vaccines. However, we need to demonstrate that they are safe and can trigger a protective antibody response in young children before they can be introduced into the national immunisation schedule.”
The Melbourne arm of the randomized controlled trial is currently recruiting 50 families with healthy two-month-old babies who have not yet received their first routine vaccinations. Participants will receive four doses of the experimental vaccine at two, four, and six months of age, followed by a booster between 12 and 15 months. All other childhood vaccines recommended by the NIP will be administered alongside the study vaccine, ensuring no child misses out on established protections.
The trial, which aims to enroll more than 1,600 babies across Australia, the US, Puerto Rico, Honduras, South Korea, and Thailand, will follow participants for up to 19 months. During that time, children will undergo three blood tests to monitor their immune responses. For some parents, the decision to participate is deeply personal. Lisa, a nurse whose three-month-old daughter Lucy is part of the study, shared her perspective: “Being a nurse, I know how super important vaccination is to keeping my baby safe,” she told MCRI. “As a parent of a young baby, especially in the winter months, you just want as much protection as possible. Without trials like this we wouldn’t discover better, more effective vaccines. Research is what helps to safe proof our children for the future.”
While the MCRI-led study is focused on expanding the reach of existing vaccine technology, a separate team of researchers in the United States is taking an entirely different approach. In a study published on July 22, 2025, in Nature Biomedical Engineering, Dr. Harvinder Singh Gill and colleagues at North Carolina State University reported promising results using dental floss as a novel vaccine delivery tool. Their idea: target the gingival sulcus—the tiny groove between teeth and gums—using floss coated with vaccine molecules.
The rationale behind this approach is fascinating. The junctional epithelium at the base of the gingival sulcus is more permeable than surrounding tissues, potentially allowing vaccines to penetrate and trigger robust immune responses. In laboratory experiments, the team coated flat tape dental floss with various vaccine compounds, including inactivated influenza virus, and used it to floss the teeth of mice. The results were striking: not only did the vaccine transfer successfully into the gum tissue, but it also stimulated strong immune responses and antibody production in the animals.
Perhaps most impressive, the floss-based vaccine fully protected mice from what would otherwise have been a fatal influenza infection. It even outperformed vaccines delivered under the tongue and matched the effectiveness of nasal vaccines. “We found that applying vaccine via the junctional epithelium produces far superior antibody response on mucosal surfaces than the current gold standard for vaccinating via the oral cavity, which involves placing vaccine under the tongue,” said Rohan Ingrole, the study’s first author from Texas Tech University. Dr. Gill added, “This is extremely promising, because most vaccine formulations cannot be given via the nasal epithelium—the barrier features in that mucosal surface prevent efficient uptake of the vaccine.”
The researchers also took the first steps toward translating their findings to humans. In a small study, they coated off-the-shelf floss picks with fluorescent dye and asked 27 people to use them. The picks successfully delivered dye into the junctional epithelium, and participants responded positively to the experience. While these results don’t prove the floss-based method can deliver vaccines in people just yet, they do suggest the technique is feasible and well-tolerated.
What makes the floss-based vaccine approach so appealing is its simplicity and potential accessibility. It’s needle-free and painless, requires little preparation, and doesn’t need refrigeration—making it both practical and potentially cheaper to distribute, especially in low-resource settings. However, as the researchers caution, more studies are needed to determine how well the method works in people, particularly in those with gum diseases or in young children who don’t yet have teeth.
These two studies—one pushing the boundaries of traditional vaccine coverage, the other reimagining the very way we deliver vaccines—underscore the ongoing evolution of immunization science. Whether through broader protection against more strains of bacteria or by harnessing everyday dental hygiene tools for painless vaccine delivery, researchers are determined to make vaccines safer, more effective, and more accessible for everyone.
With infectious diseases continuing to pose serious threats worldwide, the promise of these innovations couldn’t be more timely. As families and health professionals alike await the results of these trials, one thing is clear: the future of vaccination is shaping up to be both broader in reach and gentler in delivery.
