How does this alternative vaccination strategy differ from the current approach?
“Influenza is not a single virus, but a diverse group of viruses consisting of different subtypes, many virus strains and variants. All conventional influenza vaccines protect against a small number of variants. Because circulating influenza viruses change regularly, the composition of the vaccines must be reviewed annually to be compatible with Emerging viruses. Furthermore, current influenza vaccines for humans do not provide protection against influenza viruses transmitted from pigs or birds. If these animal viruses jump to humans, this could be the beginning of a new pandemic.
“So we developed an alternative vaccination strategy that provides broad protection against very diverse influenza strains. We are focusing on the H1N1 subtype. This type caused the 2009 influenza pandemic, which is also called swine flu. We used pigs as a research model. We vaccinated the animals using three injections , with one month between each injection. Each vaccine contains a completely different strain of the virus. One month after the last vaccination, the pigs were exposed to a high dose of a live H1N1 strain that did not match the strains in the vaccines. The pigs' immune systems had neutralized 88 % of a variety of human and swine H1 strains and reacted to each N1 strain, including avian H5N1 and H7N1. Control pigs that were vaccinated with the same strain each time, as is now common practice in vaccination campaigns, had only antibodies against Intended vaccine strain: If you were to apply this to humans, you could probably use this strategy for years, also against viruses that jump from animals to humans.
Why was this strategy tested on pigs?
“The pig is an existing, but in my opinion, underutilized research model for influenza. The infection also follows the same path in pigs and humans. The anatomy and physiology of the respiratory system are also very similar. Pigs are naturally susceptible to the same influenza subtypes as humans. Mice and rodents, The most common models for virus research, however, are not. Pigs can also be a source of new influenza viruses for humans, such as the 2009 H1N1 pandemic virus. Conversely, most viruses now circulating in pigs are descended from older human influenza viruses. The pig is therefore a Research and model targeted in this study. Insights could also improve pig vaccination.
What still stands in the way of implementing this strategy?
More research is needed. Our approach only protects against the H1N1 subtype and requires at least three injections. We have also not yet investigated the effect of basic immunity. In this research we used so-called influenza-naïve pigs, which are animals that have not yet been infected with influenza. This is different, of course, in humans, because adults have usually already been infected or vaccinated. This basic immunity can influence the effect of vaccination, for example ensuring that the response to vaccines differs for each age group. Its application to humans is also based on advice from the World Health Organization. This will take time and a change in mindset. I expect a smoother introduction into pig farming. Meanwhile, there is growing evidence that our ideas also apply to other viruses, such as HIV, MERS, and Ebola, and personalized vaccines are on the horizon.
