It’s the flu vaccination season – the time of year when millions of people are requested to receive potential protection against this virulent and potentially life- threatening virus.
Current vaccines are only effective in 30 to 40% of over 65-year-olds as the immune system weakens with age. But this season, researchers are looking at a new national flu vaccine that could protect more over 65s, and possibly save scores of lives.
The world’s first widespread human testing of a flu vaccine began last month in September. More than 10,000 people aged 65 and over have been asked to take part in a study that is supported by the NIHR (National Institute for Health Research) and is being delivered by the University of Oxford in Berkshire and Oxfordshire. Researchers believe the vaccine could have a significant impact on the global fight against the virus, which affects about a billion people worldwide every year, with 250,000 to 500,000 annual deaths (mainly in the over-65 age group). For those who receive the jab but still get the flu, researchers believe the new vaccine could also reduce the severity and duration of the illness.
It is believed the vaccine will offer a stronger protection against flu because it uses a different mechanism to get the body to protect against the virus. Under the microscope, the flu virus looks like a spherical cushion with lots of pins sticking out of it. The existing flu vaccines use surface proteins that lie on the outside of flu cells – the heads of the pins – to stimulate
the body’s immune system to produce disease-fighting antibodies. But as the virus changes each year, so
do the surface proteins, haemagglutinin and neuraminidase, meaning the flu vaccine needs to change too.
Scientists across the globe therefore have to predict what each new annual strain of flu will look like. Unfortunately, sometimes by the time the vaccine has been made, the strain of virus that is causing illness has changed, and the vaccine doesn’t work as well.
The new vaccine is different as it uses the core proteins of the virus – inside the cushion – instead of the surface proteins. These core proteins remain virtually unchanged in all influenza A viruses, giving researchers the opportunity to create vaccines that will work against all of them. Humans are susceptible to both influenza A and B, but it is influenza A that causes the majority of severe illnesses and deaths.
Crucially, the new vaccine stimulates the immune system to boost influenza-specific T-cells, instead of antibodies, that kill the virus as it tries to spread through the body. Everyone has some influenza-specific T cells already, but numbers of them are often too low to be protective. Previous research found that these T-cells can help fight more than one type of flu virus, and researchers believe this means more people could be protected and the severity and duration of flu may be reduced.
About 1,000 over 65s registered at six GP practices are taking part in the study, known as the ‘Invictus’ trial, in Berkshire and Oxfordshire this winter.
Some 500 people will receive the regular, annual immunisation in combination with the new vaccine, which has successfully undergone safety testing. Others will receivethe regular immunisation and a placebo shot, so the two can be compared. Patients will not be told whether they are receiving the new vaccine or placebo. A further 1,000 participants will take part in the trial next season.
The vaccine was developed by Oxford University’s Jenner Institute with Vaccitech, a spin-out company from the institute. The study is being sponsored by Vaccitech and managed by the University’s Nuffield Department of Primary Care Health Sciences with support from the NIHR Clinical Research Network Thames Valley and South Midlands, a Department of Health-funded organisation that provides staffing to ensure research studies are run in the health service.
Professor Sarah Gilbert, professor of Vaccinology at the university and co-founder of Vaccitech, says: ‘Every year, flu in older adults causes serious illness and sometimes death. We want to improve the situation, but in order to do that we need volunteers to help us test a new vaccine.’
Chris Butler, principal investigator of the study, is director of the Primary Care Clinical Trials Unit, University of Oxford, and a practising GP in Mountain Ash, South Wales. He says there has been ‘a huge response’ to the study, and that ‘even though we have only just started vaccinating, we already have enough volunteers for this season.’
Researchers recruited forward-thinking, research-minded practices in Oxfordshire to help with the study. They asked GPs to write to patients who might be eligible to take part in the trial, to explain the study and that patients who were interested in taking part should contact the Clinical Trials Unit.
Appointments were then set up with GP surgeries to meet the study’s nursing staff, explain the study, confirm eligibility of patients, take informed consent and administer the vaccine.
Mr Butler says the GP and the practice staff involved in the trial ‘are making a tremendous contribution.’
‘As well as putting us in touch with patients and giving us the space to carry out vaccinations, they are also helping us with following up patients who have been vaccinated as part of the study,’ he says.
He adds that practice staff have been ‘key to making it all happen’. ‘As somebody who does a lot of clinical trials in general practice, this is an amazing study. We’ve been overwhelmed by the dedication of the research practices helping us implement it and the positive response from patients who have come forward wanting to help with our research.’
The recruitment of 1,000 patients to take part in next year’s study of flu vaccinations is ‘going well’, he says, ‘and hopefully we will reach our target of 2000 patients in total over the two seasons.’
Now that the first people in the trial are being vaccinated, he says data will be coming to researchers ‘all the time over the coming winter’. However, it will be two years ‘before we get any real data see if this new approach brings benefits – and we hope it will.’
Mr Butler explains that phase two of the study will be about examining how effective it has been: ‘We need to do more trials after this one. But if it works really well, who knows – maybe we won’t need to give a flu vaccine every year.’
He says that if this new approach to flu vaccinations works, ‘we could be talking about saving millions of people from the consequences of flu, and billions of pounds in savings for the NHS.’
‘It would be a considerable step forward for healthcare if the vaccination works’, and the whole winter crisis associated with the NHS and flu ‘will look very different if we can offer better flu vaccines’, he says.
The implications of this new vaccination ‘are massive, not only for the NHS but worldwide’, he believes. His view follows recent warnings of an upcoming severe flu epidemic this winter from the Southern Hemisphere.
Mr Butler says those involved in the clinical trial are ‘mindful of this’, however, he stresses the new vaccination will only have a limited impact given the size of the study.
‘But if this vaccine works in the future then we should get better protection against all flu strains because even if they have changed a bit they should be “nailed” by this new approach,’ he adds.
For Mr Butler, the study is a ‘win-win for general practice’, and those patients taking part.
He believes this groundbreaking research ‘could transform care, save lives, prevent numerous hospital admissions, and serious illness’. Time will tell whether he is correct.IN