Is a new flu vaccine closer or actually further away?

05 Apr 2019 | Back to News, Publications and Annual Reports

Not every runny nose means you have flu. It's only after you've actually contracted the flu virus that we call it flu. During an average flu epidemic in the Netherlands, this happens to about half a million people. The majority of them recover within a couple of weeks, but some people can develop very serious complications. In the Netherlands, people in risk groups can be vaccinated against flu, but the current flu vaccine is under pressure – literally and figuratively.

Literally, because the flu virus is 'smart' enough to circumvent the effectiveness of these vaccines. And figuratively, because the uncertainty over the effectiveness of flu vaccines has a negative impact on the public opinion of them. As a result, the number of people who take up the flu vaccine is relatively low.

Scientists are currently looking into the possibility of what is known as a universal flu vaccine. This would mean that only one vaccine would be required, rather than the vaccine having to be adapted annually to the flu viruses that are doing the rounds that year. If it works, annual flu vaccinations may well be a thing of the past.

Inducing antibodies

Like most vaccines, a flu vaccine aims to induce broadly neutralising antibodies. These are antibodies that can protect against a wide variety of flu viruses. They do this by leading these viruses to specific cells of the immune system, called phagocytes, which then ingest them. The current vaccine is directed at those parts of the virus which mutate easily, while the universal vaccine is directed at parts which don't mutate or hardly mutate at all. In humans, these kinds of antibodies can be found in small quantities in the blood. Until now, it had not been clear whether a vaccine could also induce these antibodies.

The immune system of macaques and humans respond in a similar way to flu vaccines and infection with a flu virus. BPRC researchers have compared the blood of a group of flu-infected macaques with that of vaccinated primates. This indicated that primates have a high concentration of flu-specific phagocytic antibodies both after vaccination and after infection. This strongly suggests that a vaccine could also induce these antibodies in humans.

Food for thought

Although this is primarily good news, the researchers also discovered the potential risk of these antibodies: in extremely low concentrations, they can cause the virus to be transported to other cells (of the immune system) which are unable to eliminate it, but which could cause the flu virus to spread further through the body. This would obviously be counterproductive.

Therefore, further research is necessary before this new type of flu vaccine can be introduced. All in all, this study provides new food for thought on a new universal flu vaccine.

To learn more, read the full article here.