A Better Grip: T Cells Strengthen Our Hand against Influenza Clinical Infectious Diseases, 52 (1), 8-9 DOI: 10.1093/cid/ciq018Flu vaccines are important and useful, but also relatively ineffective compared to many other vaccines. Immunity is imperfect, there are many ‘strains’ of influenza in a given year only some of which are addressed by the available vaccine (though often the most common ones) and one year’s vaccine does not provide immunity to subsequent years’ influenza because the virus changes so much. Well, actually that’s not exactly true: The influenza virus has various different parts, and the parts that the traditional flu vaccine uses to induce an antigenic reaction in the potential hose is highly variable. Other parts of the flu virus are not as variable. If only a vaccine could be developed that uses the less variable part of the influenza virus, then perhaps it would be a universal, long-lasting vaccine that you take once, and become pretty much immune to all future influenza.
Well, it is possible that this has actually happened. A British research team has developed a vaccine that induces t-cells to respond to a conserved part of the influenza virus. It appears to be effective, and it appears to be safe. This is very preliminary …. much more work needs to be done to prove that it is safe, to suss out any rare side effects and, most importantly at this stage, to determine the ideal dosage.
Here’s what the researchers say:
…A vaccine providing protective immunity to the highly conserved internal antigens could provide longer-lasting protection against multiple influenza subtypes.
… We prepared a Modified Vaccinia virus Ankara (MVA) vector encoding nucleoprotein and matrix protein 1 (MVA−NP+M1) and conducted a phase I clinical trial in healthy adults.
… The vaccine was generally safe and well tolerated, with significantly fewer local side effects after intramuscular rather than intradermal administration. …
… We conclude that the vaccine was both safe and remarkably immunogenic, leading to frequencies of responding T cells that appear to be much higher than those induced by any other influenza vaccination approach. Further studies will be required to find the optimum dose and to assess whether the increased T-cell response to conserved influenza proteins results in protection from influenza disease.
Traditional vaccines teach the body’s immune system to create appropriate antibodies to fight a particular strain of flue. This new vaccine induces increased production of T-cells, using a different feature of the immune system. T-cells would destroy virus-infected cells.
The reported trial involved vaccinating eleven volunteers, then infecting them and eleven unvaccinated volunteers with the H2N2 flue. The vaccination appeared to work well. This is the first time this has been done in people, according to the study’s author:
This is the first time anyone’s tested if you can boost somebody’s T-cell response to flu and, having done that, if it helps protect against getting flu. It’s the first time anybody’s done that in people. Fewer of the people who were vaccinated got flu than the people who weren’t vaccinated. We did get an indication that the vaccine was protecting people, not only from the numbers of people who got flu but also from looking at their T-cells before we gave them flu. The people we vaccinated had T-cells that were more activated. The people we hadn’t vaccinated had T-cells as well but they were in a resting state so they would probably have taken longer to do anything. The volunteers we vaccinated had T-cells that were activated, primed and ready to kill. There were more T-cells in people we vaccinated and they were more activated.
Also, this approach to vaccination may work better on older individuals, for whom the traditional vaccine tends to be less effective.
The work needed to verify this result and bring it to the point of being an actual vaccine that we can have the use of, assuming the result holds up, will take time, probably years. But since the work was reported as an Open Access paper, you can read about it now (click the links below).
Berthoud, T., Hamill, M., Lillie, P., Hwenda, L., Collins, K., Ewer, K., Milicic, A., Poyntz, H., Lambe, T., Fletcher, H., Hill, A., & Gilbert, S. (2011). Potent CD8+ T-Cell Immunogenicity in Humans of a Novel Heterosubtypic Influenza A Vaccine, MVA-NP+M1 Clinical Infectious Diseases, 52 (1), 1-7 DOI: 10.1093/cid/ciq015
Hambleton, S. (2011). A Better Grip: T Cells Strengthen Our Hand against Influenza Clinical Infectious Diseases, 52 (1), 8-9 DOI: 10.1093/cid/ciq018