When was the last time you were vaccinated? If the answer leaves you scratching your head or remembering the days before primary school, then you’re the rule rather than the exception. While you’re never too old to get vaccinated against preventable diseases, the uptake of adult vaccinations remains worryingly low.
In contrast, childhood vaccination has been one of the great public health success stories, helping to protect against deadly diseases such as diphtheria, whooping cough and measles. Most of us are conscientious about making sure our children follow a vaccination schedule that starts at eight weeks and continues into the school years.
Adults may remember to get a typhoid or hepatitis jab before travelling abroad, but we tend not to think of vaccination as a routine part of looking after our health, even though vaccination (along with healthy diet and exercise) is a key tool for minimising disability and improving quality of life throughout life. Yet every year tens of thousands of people die or are hospitalised as a result of vaccine-preventable infections such as whooping cough and flu.
Thomas Breuer, vaccines chief medical officer at GSK, in his work as a physician, has seen “the struggle that patients have recalling their vaccination history and how healthcare providers often don’t feel well-enough informed to discuss vaccination schedules and the potential benefits for adults”.
So what vaccines should adults be discussing with their healthcare professionals – and when? Prof Mark Jit, professor in vaccine epidemiology at the London School of Hygiene and Tropical Medicine, says there are three groups of adults who may particularly need vaccines. “One group is adults with conditions such as asthma or heart disease. They’re at higher risk of getting complications when they have diseases like flu, so they need to make sure they get their flu vaccines.”
The second is pregnant women, who should consider being vaccinated against whooping cough as well as flu .
“These diseases can cause complications in pregnancy,” says Jit. “When pregnant women get vaccinated, very often they can also help protect their children because the antibodies they develop to the vaccine can transfer to their children.”
The third group is older adults. In the UK, vaccination against flu and pneumococcal infection is recommended for all those over the age of 65; the shingles vaccine is recommended for those over 70. In other European countries, vaccination against some of these diseases is recommended for those as young as 50 since the risk of pneumococcal disease and influenza starts to rise as the immune system weakens in people in their mid-40s.
“Flu can result in pretty serious complications, such as pneumonia,” says Jit. These can be fatal: in the UK, about 600 people die every year from complications directly related to flu, though the actual number is probably higher. Throughout the EU, the figure is between 15,000 and 70,000 (exact numbers are hard to come by, as the cause of death is not always recorded as flu).
The need for vaccination may be most acute in these high-risk groups, but all adults can potentially benefit from vaccination. And there’s more to vaccination than individual protection, says Breuer, explaining that, as well as a direct impact, there is also an indirect impact, or the “herd effect”. Once the proportion of people in a community who have been vaccinated against a contagious disease reaches a certain point (usually about 90%), that helps protect even those who haven’t been vaccinated, because the opportunity for an outbreak is much lower.
In some countries, adults are now vaccinated against whooping cough, as it is often transmitted from adults to newborn babies – the National Health Service introduced pertussis vaccination for pregnant women in the UK after more than a dozen babies died in the 2012 outbreak. Conversely, Breuer says, it makes sense to invest in flu vaccination programmes for children, to stop them passing it on to older adults and to reduce overall morbidity and mortality.
The UK has a better record of adult vaccination than many other countries. The NHS’s vaccine schedule clearly lays out the age at which adults should receive particular vaccines, including the flu vaccine and pneumococcal vaccine (which helps protect against pneumonia and meningitis), and the shingles vaccine. Take up is relatively good for flu vaccination – 71% of adults over the age of 65 receive it.
But developing an effective immunisation programme for adults is less straightforward than developing one for children. First, most adults don’t have regularly scheduled checkups the way that babies or pregnant women do, so they have fewer opportunities to discuss vaccination with their doctor and to get vaccinated.
Second, the body’s immune system starts to age after early adulthood and become less responsive, so vaccines that were designed to work well in children may not work as well when we age.
But the good news is that new technologies can boost immune response in older people. Some new vaccines contain adjuvants – chemical compounds that are designed to boost the potency of the vaccine – specially designed with older age groups in mind. Adding the adjuvant may allow the immune system to respond more quickly and powerfully to infection.
