This information is for people who have chronic obstructive pulmonary disease (COPD). It looks at flu and pneumonia jabs, which your doctor may recommend to prevent lung infections.
We haven't looked at the research on flu and pneumonia jabs in the same detail we have for the other treatments we cover. (To read more, see Our method.) But we've included some information in case you're interested.
What are they?Flu jabs
Flu, or influenza, is a common infection. It can make it harder for you to breathe, and make other symptoms of COPD worse as well. Your doctor may advise you to have an injection to prevent flu.
You need to have a new injection every year. That's because the viruses that cause influenza change from year to year. The jab you had last year may not protect you from this year's virus.
The best time for a flu jab is between late September and early November.Pneumonia jabs
You can also have an injection to protect you against a type of pneumonia called pneumococcal pneumonia. It's caused by a type of bacteria called pneumococcus. It's the most common form of pneumonia. If you have COPD, your doctor may recommend an injection to protect against pneumococcal pneumonia.
You may only need one dose of the pneumonia vaccine. You won't need a new jab every year. Some people with a weak immune system need a second dose, usually after five years. Ask your doctor if you think this might apply to you.
How can they help?
If you have chronic obstructive pulmonary disease (COPD), catching flu can bring on an attack of symptoms. Having a flu jab each year can help stop you getting flu. Some research shows that having a flu jab can also reduce the number of COPD attacks you get. 
The research on pneumonia jabs is mixed.
Some research shows that the jab can stop people getting pneumonia.  But we're not certain whether it works if you have COPD.
Some studies show that having this injection won't reduce your chances of getting pneumonia if you have COPD, or stop you having attacks and needing to go to hospital.  
How do they work?
Vaccines help your immune system fight off infections. They contain dead or weakened viruses or bacteria. Your body learns how to fight the infection. When you come into contact with the infection again, your body already knows how to fight it.
Can they be harmful?
The flu vaccine is made in eggs, so people who are allergic to eggs shouldn't have the vaccine. Talk to your doctor if you aren't sure whether the vaccine is safe for you.
Having a flu jab can't give you flu. The viruses in the vaccine are dead and can't cause you any harm.  But the injection may cause a sore arm. Some people have muscle aches or a mild fever after their jab.
The pneumococcal vaccine is also very safe. It can't give you pneumonia or any other illness. Some people get minor side effects, like soreness where the needle goes in.