In a new study published in innate immunology, Researchers at Boston Children’s Hospital demonstrated that by combining the original COVID-19 mRNA vaccine with an immune system booster known as an adjuvant, the duration of the vaccine’s protection in mice was extended from several months to up to two years. The combination also showed a more pronounced response to Ormicron’s viral components than the vaccine alone. Researchers say that introducing such adjuvants into mRNA vaccines could reduce the need for frequent boosters due to waning antibodies and new virus variants. This discovery points to a fundamentally new approach. Rather than chasing new variants with updated boosters, such adjuvants could train the immune system to respond more broadly and remain effective as the virus evolves.
A research team led by Dr. Ivan Zanoni, a professor of immunology at Boston Children’s Hospital, developed an adjuvant from branched sugar molecules known as mannans found in the outer cell wall of yeast. Candida. They combined mannan with alum, another traditionally used vaccine adjuvant, to create “man adjuvant.”
Our strategy takes advantage of the immune system’s innate ability to increase broadly in response to a variety of components found within and on the surface of pathogens. Although mRNA technology has been the biggest advancement in vaccine technology in the past 20 years, we thought there was still room to improve this platform. ”
Dr. Ivan Zanoni, Professor of Immunology at Boston Children’s Hospital
In previous research, Zanoni’s team used mana adjuvants to increase the effectiveness of protein-based influenza vaccines. This latest study tested the effectiveness of the adjuvant when combined with an mRNA vaccine.
“After receiving a COVID-19 vaccine, antibody levels decline after six months, and boosters must be continually given to maintain strong protection,” Zanoni said. “Viruses mutate rapidly, so the antibodies your body produces from the original vaccine cannot recognize new versions of the virus that are in circulation.”
mRNA COVID vaccines contain genetic material that encodes instructions for building part of the virus’s outer spike protein, which is wrapped in a protective shell of fat that shuttles the vaccine within immune cells. Zanoni’s team first confirmed that the vaccine remained stable when combined with an adjuvant.
Next, the researchers tested the vaccine and adjuvant in mice. Mice given the mana-adjuvant-containing vaccine still had antibodies against the virus’s spike protein up to two years later, whereas common vaccines provide protection for several months.
Finally, to investigate protection against virus evolution, Zanoni’s team exposed vaccinated mice to a mutated coronavirus spike protein from the Omicron variant. Mice given a COVID-19 vaccine containing a mana adjuvant had a significantly stronger immune response to the mutant strain than mice given only the mRNA vaccine.
For future studies, the team will continue to elucidate the molecular mechanisms of how adjuvants work to stimulate the immune system, especially since the immune system’s response to fungi is poorly understood. The research team filed a patent on manadjuvant and formed a spin-off biotechnology company to further develop the technology for eventual use in human trials.
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Boston Children’s Hospital
Reference magazines:
Jena, K.K. Others. (2026). Glycan-based adjuvants extend the scope and duration of protection of mRNA-based vaccines. innate immunology. DOI: 10.1038/s41590-026-02517-3. https://www.nature.com/articles/s41590-026-02517-3
