Along with clean water, immunisations have done more to prevent child death than any public health advance ever - but they're not only for babies. There are vaccines to protect you against the most dangerous infections at every age.
As a general rule, if you're travelling anywhere outside Western Europe, USA or Australasia, check to see if you need travel vaccines. Travelling to far-flung locations can be incredibly exciting and rewarding, but it can also expose you to diseases that are less likely to occur at home.
- Insect-borne conditions such as malaria, dengue, yellow fever and Zika virus.
- Diseases acquired from eating and drinking, such as hepatitis A and traveller's diarrhoea.
- Diseases acquired from others or conditions of poor hygiene, such as hepatitis B and Ebola virus.
- Diseases acquired directly from animals, such as rabies.
Remember, vaccination courses need to be planned well in advance. Some vaccinations involve a course of injections at specified intervals. And some vaccinations can't be given together.
I've only once seen a case of tetanus, sometimes called lockjaw, in 30 years as a doctor. That's not because the risk has gone - the germ that causes tetanus is commonly found in soil, and can get into your body through cuts in the skin. It's immunisation that stops it being a daily fear. Every child born today is offered a full course of immunisation against tetanus - three injections in their first year, a pre-school booster at 3½ years old and a teenage booster at 14.
Getting all five immunisations should offer good protection, but in some situations you may be offered a booster. If you're travelling to a foreign country with limited medical facilities, and your last booster was over 10 years ago, your practice nurse (or some pharmacists) can offer you a top-up vaccination. Likewise, if you have a deep wound, or dirt has got into a cut, you may be offered a booster at A&E if your last booster was over a decade ago.
All babies are now offered immunisation against Men B - the germ that causes most cases of meningococcal meningitis and blood poisoning. Since 2013, teenagers have been offered a vaccine that offers protection against Men A, C, W and Y. This is because there's a spike in meningitis among older teenagers.
If they didn't have it at 14, make sure university students get protected.
Whooping cough, or pertussis, causes a miserable cough in adults that can last for months, but it rarely causes serious complications. In babies, however, it can be very serious and even fatal.
All babies are offered immunisation against whooping cough at 2, 3 and 4 months - but they're vulnerable to catching it until they've had all their injections. In recent years there have been more cases of whooping cough in the UK (it tends to go through cycles with peaks every few years). As a result, all pregnant women are now offered immunisation between 20 and 32 weeks of pregnancy.
The vaccine is completely safe for your baby - it doesn't include any live germs at all. Instead, it contains purified parts of the germ which allow your body to recognise an enemy and make tailored antibodies specific to the pertussis germ. These antibodies pass across the placenta to your baby, providing them with 'passive' immunity. This is enough to protect them until they've had a chance to be immunised themselves.
Shingles is caused by the same virus that leads to chickenpox. You don't 'catch' shingles - after you've had chickenpox, the virus lives on in your nervous system for life. It's dormant until it reawakens, possibly when your immune system is weaker (maybe because of stress, getting older or taking medicines that affect your immune system). Shingles causes a painful rash in a strip around one side of your trunk or face. The rash settles within a few weeks but you can be left with distressing nerve pain.
As you get older, your ability to fight off the shingles virus drops, which is why the vaccine is available on the NHS for people over 70. At the moment, a phased roll-out programme is going on to ensure everyone from age 70-80 years old is covered. Once this is completed, everyone will be offered a shingles vaccine around their 70th birthday. If you're in your 70s, your pharmacist can advise whether you're eligible.
Having other long-term health conditions like heart, lung, kidney or liver problems, or type 2 diabetes, can also make it harder to fight off infection. If you have any of these conditions, or are over 65, you should be offered an annual flu vaccine. That's because people in these groups are at higher risk of serious complications like pneumonia.
Many people who aren't in at risk groups still want to be protected - even though most healthy people will recover completely within a week or two, having flu is still no fun for anyone, especially if you can't afford to be ill because of your job or other commitments. You can still get a vaccine - speak to your pharmacist, who can give you one privately.
People at high risk of flu are also more likely to suffer serious complications from a germ called 'Strep pneumoniae'. You can get a pneumococcal vaccine, which protects against the pneumonia, meningitis and blood poisoning it can cause. Most people only need one immunisation to protect for life, although if you have certain health conditions you may need a booster every five years.
Effective prevention relies on everyone (or nearly everyone) being immune - please encourage your family to get protected!