Single-Shot Respiratory Vaccine Could Transform Pharmacist Counseling and Immunization Rates

The burden of managing the "tripledemic" of seasonal influenza, COVID-19, and respiratory syncytial virus (RSV) may soon become significantly lighter for both patients and pharmacists. A promising preclinical study published in Science Advances shows that a single-shot vaccine candidate can effectively protect against all three major respiratory viruses that have challenged public health efforts since 2022. The research, conducted by investigators at the University at Buffalo, demonstrates that combining 5 viral proteins into 1 injection triggers robust protective immunity against all 3 viruses across multiple animal models, with no signs of immune interference between the antigens.¹

The Tripledemic Burden: A Growing Public Health Crisis

The tripledemic has imposed a significant burden on the United States’ health care system. The 2023 to 2024 respiratory virus season alone was associated with approximately 1 million combined hospitalizations in the US. Yet despite the severity of this public health challenge, vaccination rates remain concerningly low among the most vulnerable populations. As of November 2024, only 35% of Americans aged 75 years and older have received an influenza vaccine, 18% received a COVID-19 vaccine, and only 40% received an RSV vaccine.¹

The 3 viruses often circulate simultaneously during fall and winter months, overwhelming health care resources and placing immunocompromised populations at higher risk. Currently, there is no approved vaccine that combines protection against all 3 viruses, making multiple injections the standard of care. Pharmacists recognize that this fragmented approach to respiratory disease prevention creates a significant barrier to patient uptake.

The Convenience Factor: How a Single Shot Could Change Practice

For pharmacists managing immunization programs, the convenience factor of a combination vaccine cannot be overstated. Research indicates that many patients defer respiratory vaccinations simply because scheduling and administering multiple shots is inconvenient.¹

"We know that many individuals skip one or more of the 3 recommended respiratory vaccines, sometimes simply because it's inconvenient," Bruce Davidson, PhD, research associate professor in the University at Buffalo's Department of Anesthesiology, said. This inconvenience barrier is particularly significant among older adults, who are most vulnerable to severe respiratory disease.¹

According to the study's corresponding author, Jonathan Lovell, PhD, from the University at Buffalo's Department of Biomedical Engineering, a single 3-in-1 shot would significantly streamline patient counseling and improve immunization uptake. "For pharmacists on the front lines of immunization, what would a single 3-in-1 shot mean for counseling patients who currently have to schedule separate flu, COVID-19, and RSV vaccines? Our study is just a concept study, but in theory, a many-in-one vaccine to prevent respiratory disease could be possible in the future. That may be administered annually to extend protection,” he said in an interview with Pharmacy Times. The potential for an annual combination shot could represent a paradigm shift in how pharmacists approach respiratory disease prevention counseling.

Study Design: Multiple Animal Models Confirm Efficacy

The preclinical trial was conducted across 3 animal models to ensure robust assessment of vaccine efficacy and safety. Researchers vaccinated mice, ferrets, and cotton rats with the 3-in-1 vaccine candidate and measured immune responses against all 3 viruses. The choice of multiple species is significant—ferrets are particularly valuable for respiratory disease research because their respiratory physiology closely mirrors that of humans, whereas cotton rats are susceptible to RSV infection, making them ideal for evaluating protection against this virus.¹

The vaccine formulation included 5 viral proteins: 3 influenza proteins and proteins from SARS-CoV-2 and RSV. To enhance immunogenicity, the researchers incorporated immune-boosting adjuvants known as PHAD (synthetic monophosphoryl lipid A) and QS-21 into the vaccine platform. These adjuvants have demonstrated immunostimulatory properties in previous vaccine development efforts, and their inclusion in this combination formulation was designed to maximize the immune response to all three pathogens simultaneously.¹

Immunogenicity Data: Comparable to Single-Virus Vaccines

A critical concern with any combination vaccine is whether protective immunity against individual pathogens might be diminished by combining them into a single formulation. The study's findings were reassuring on this front. The antibody responses elicited by the 3-in-1 vaccine were comparable to those produced by vaccines targeting just a single virus. This result suggests that combining the 3 vaccines into 1 shot did not compromise the immunological response to any individual pathogen.¹

When asked about his confidence in these findings as the vaccine advances toward human trials, Lovell provided important context regarding the platform's immunological bandwidth. "We believe that since we are including only minimal antigens—the proteins for which neutralizing antibodies can be elicited—there is a lot of bandwidth to add many proteins into the vaccine. More studies would be needed to test how immune durability compares with this approach, and yes, moving the testing to humans would be a big step that would be required to ultimately gauge the approach. I think the safety profile would be advantageous to receive a single shot compared to multiple separate injections," Lovell said. This response underscores the potential for the platform to accommodate additional respiratory pathogens in future iterations.

The CoPoP Platform: Novel Delivery Technology

The vaccine uses the CoPoP platform—a sophisticated nanoparticle delivery system that has been under development for more than a decade by Lovell and his team. CoPoP consists of tiny spherical nanoparticles made of cobalt and porphyrin with an outer shell of phospholipid. The platform works by attaching viral proteins to the nanoparticles via histidine tags (His-tags)—short strings of amino acids that have a natural affinity for metals—allowing them to form a strong bond with the cobalt ions in the nanoparticles.²

Once administered into the body through the vaccine, the viral proteins displayed on the nanoparticle surface help train the immune system to recognize and defend against the viruses. This approach to antigen presentation on a particulate surface has been shown to enhance immunogenicity compared to soluble protein antigens. The platform has already demonstrated promise in clinical trials for a COVID-19 vaccine candidate developed by POP Biotechnologies, Inc, a spinoff company from the University at Buffalo.¹

Timeline and Realistic Expectations for Commercialization

Although the preclinical results are encouraging, pharmacists should maintain realistic expectations about when a combination respiratory vaccine might become available. The research is still in the earliest stages of development.

"I think that we are still at the preclinical stage, and so far we have not gotten feedback from industry about this approach. If it were to proceed, it would take many years before it could reach commercial production. In theory, I do think such approaches could be useful to extend protection to more respiratory diseases beyond influenza only," Lovell noted.

The pathway from preclinical animal studies to an FDA-approved vaccine typically requires several years of additional research, including investigational new drug applications; phase 1, 2, and 3 clinical trials; and ultimately, FDA review and approval. Given that this research is just beginning human trial preparation, a realistic timeline for commercialization would likely be measured in years rather than months.¹

Industry Interest and Future Platform Expansion

Despite the early stage of development, the CoPoP platform's flexibility has attracted attention from vaccine manufacturers exploring combination approaches to the tripledemic. Several major pharmaceutical companies have ongoing studies evaluating potential options for combination vaccines targeting COVID-19, flu, and RSV. These parallel efforts suggest industry recognition that combination respiratory vaccines may represent the future of immunization strategy.³

The platform's ability to accommodate multiple viral proteins opens the door to potential expansion beyond the current 3-pathogen formulation. In theory, the CoPoP platform could eventually be adapted to include protection against additional respiratory viruses, though such expansions would require their own clinical validation.

Implications for Pharmacy Practice

For pharmacists, these developments signal the need to prepare for significant changes in immunization practice. The current paradigm of administering 3 separate injections for respiratory disease prevention has clear limitations in terms of patient convenience, health care resource utilization, and vaccination uptake rates. A single annual shot that provides comprehensive protection against flu, COVID-19, and RSV could meaningfully improve vaccination rates among vulnerable populations while reducing the administrative burden in pharmacy immunization programs.

The transition from multiple shots to a single combination injection could simplify patient counseling around respiratory disease prevention. Pharmacists would no longer need to explain why patients need 3 separate injections with potentially different timing considerations. Instead, a single annual visit could address all 3 major respiratory pathogens simultaneously, removing a significant barrier to immunization.

REFERENCES

1. Li Q, Huang W, Mahmoud S, et al. A subunit vaccine for multiple respiratory viruses. Sci Adv. 2026;12(26):eaea3227. doi:10.1126/sciadv.aea3227

2. Study: Three-in-one vaccine shows promise against ‘tripledemic’. News release. EurekAlert! June 30, 2026. Accessed July 9, 2026. https://www.eurekalert.org/news-releases/1134246

3. Easing the healthcare burden of the seasonal triple-demic and Pfizer's unwavering commitment to public health. News release. Pfizer. Accessed July 9, 2026. https://www.pfizer.com/news/articles/easing_healthcare_burden_seasonal_triple_demic_and_pfizers_unwavering_commitment