Why are some people offered vaccines and others are not?
Vaccines are given to the people who need them most – usually those who are most vulnerable to the disease the vaccine works against. The age you receive a vaccine can also be important to ensure you get protection at the right time. The cost-effectiveness of vaccination can also play a role in decisions about who it is offered to.
Many vaccines and boosters are given ahead of key milestones in life when your risk of catching a disease is likely to increase dramatically. This is why children will be given a booster against diphtheria, polio, tetanus and whooping cough before they start school, for example, as they are more likely to be exposed to these diseases when they start mixing with lots of other children. Children aged 12-13 years old are also offered the HPV vaccine so they can develop immunity before they are likely to be exposed to the virus which is often spread through close contact during sexual interactions. Testing has shown that this earlier vaccination against HPV also produces a stronger immune response compared with older teenagers.
In some cases, vaccines have been shown to be safer and more effective when given at a certain age. The vaccine against rotavirus, for example, is not recommended for children older than 15 weeks for the first dose and 24 weeks for the second dose because a rare complication that causes an obstruction in their intestines becomes more common in older infants.
In the UK, the annual seasonal flu vaccine is offered by the NHS to people aged 65 and older, along with certain groups with health conditions, as they are more vulnerable to fall seriously ill or even die from a flu infection. Flu vaccines are also offered to children at school to protect them but also because they are a population where the virus can readily spread, meaning they can bring it home and put vulnerable people at risk.
With some vaccine programmes, the aim is to try to achieve herd immunity and you can read more about that in What is herd immunity?
Is cost a factor in who gets a vaccine?
Public health costs money, and vaccines, like other medicines are produced by for-profit companies. National health authorities make decisions about the risk of a disease and the cost of treating it versus the cost of a vaccination programme. Funding vaccines also means there is less money for other ways of preventing and treating disease, so health authorities such as the NHS constantly have to decide where tax-payers money is best spent.
Every country has its own decision-making process when it comes to who gets vaccines and when. Generally, manufacturers, regulators and the World Health Organization will make recommendations about who should get a vaccine and when. The realities of health economics and the challenges of getting vaccines to some parts of the world also play a role. In the UK, the Joint Committee on Vaccination and Immunisation (JCVI) assesses the burden of diseases which might be vaccine-preventable using data gathered by the UK Health Security Agency. If a suitable vaccine is available, and has been assessed as safe, efficacious and properly manufactured by the MHRA, JCVI reviews data on its safety, its ability to induce immunity in the population and the efficacy and likely impact of the vaccine. Finally, JCVI assesses cost-effectiveness to help guide whether or not it meets NHS thresholds for use of tax-payers money in the benefits to the population that it provides, and who should be vaccinated to accrue those benefits. JCVI makes recommendations to the Department of Health and Social Care who review the advice carefully and develop policy about the use of any new vaccine and work with HM Treasury to provide the funding for the NHS to implement the new programme.