How do inoculations work

Vaccines are now widely available. In many cases, you do not need an appointment. Skip directly to site content Skip directly to page options Skip directly to A-Z link. Section Navigation. Important update: Healthcare facilities. Learn more. To maximize protection from the Delta variant and prevent possibly spreading it to others, get vaccinated as soon as you can and wear a mask indoors in public if you are in an area of substantial or high transmission.

Updated May 27, Minus Related Pages. They remain in your bloodstream, and if the same germs ever try to infect you again — even after many years — they will come to your defense. Only now that they are experienced at fighting these particular germs, they can destroy them before they have a chance to make you sick. This is immunity. It is why most people get diseases like measles or chickenpox only once, even though they might be exposed many times during their lifetime.

Vaccines to the Rescue Vaccines offer a solution to this problem. They help you develop immunity without getting sick first. Vaccines are made from the same germs or parts of them that cause disease; for example, polio vaccine is made from polio virus.

But the germs in vaccines are either killed or weakened so they won't make you sick. Vaccines containing these weakened or killed germs are introduced into your body, usually by injection.

Then they stay in your body, giving you immunity. If you are ever exposed to the real disease, the antibodies are there to protect you. But how does this seemingly counterintuitive process work? Kelwalin Dhanasarnsombut details the science behind vaccines.

However, the most abundant ingredient in a vaccine is water. Some vaccines also contain aluminium — usually in the form of aluminium hydroxide.

Aluminium is found naturally in nearly all food and drinking water and is used in vaccines to strengthen and prolong the immune response they generate. Aluminium is also found in many other medicines, such as heartburn medication. It is an organic compound which is found in many living things and humans produce formaldehyde naturally as part of the metabolic process. While it is true that high levels of formaldehyde can be harmful to humans, the amount of formaldehyde present in any vaccine is fifty times smaller than that found in a pear.

Both can be found online. Immunisation is a proven tool for controlling and eliminating life-threatening infectious diseases and is estimated to avert between 2 and 3 million deaths each year - World Health Organization. How vaccines work How do vaccines work and why are they important? What is vaccination? How does vaccination work? Is it better for my child to get the disease naturally? How effective is vaccination?

Have vaccines made a difference? If these diseases are so rare, why does my child need to be vaccinated? Types of Vaccines The key to vaccines is injecting the antigens into the body without causing the person to get sick at the same time. Advantages: Because these vaccines introduce actual live pathogens into the body, it is an excellent simulation for the immune system. So live attenuated vaccines can result in lifelong immunity with just one or two doses.

Disadvantages: Because they contain living pathogens, live attenuated vaccines are not given to people with weakened immune systems, such as people undergoing chemotherapy or HIV treatment, as there is a risk the pathogen could get stronger and cause sickness.

Additionally, these vaccines must be refrigerated at all times so the weakened pathogen doesn't die. Specific Vaccines: Measles Mumps Rubella MMR combined vaccine Varicella chickenpox Influenza nasal spray Rotavirus Inactivated Vaccines: For these vaccines, the specific virus or bacteria is killed with heat or chemicals, and its dead cells are introduced into the body. Advantages: These vaccines can be freeze dried and easily stored because there is no risk of killing the pathogen as there is with live attenuated vaccines.

They are also safer, without the risk of the virus or bacteria mutating back into its disease-causing form. Disadvantages: Because the virus or bacteria is dead, it's not as accurate a simulation of the real thing as a live attenuated virus.

Therefore, it often takes several doses and "booster shots" to train the body to defend itself. Advantages: With these vaccines, the chance of an adverse reaction in the patient is much lower, because only a part or the original pathogen is injected into the body instead of the whole thing. Disadvantages: Identifying the best antigens in the pathogen for training the immune system and then separating them is not always possible. Only certain vaccines can be produced in this way. Specific Vaccines: Diphtheria Tetanus Conjugate Vaccines: Some bacteria, like those of Hib disease , possess an outer coating of sugar molecules that camouflage their antigens and fool young immune systems.