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A guide to … administering vaccines

Laura Craig
Immunisation Nurse Specialist
Immunisation Hepatitis and Blood Safety Department
Health Protection Agency

Delivering vaccines is an important part of the day-to-day work of the primary care nurse so a detailed procedure should be followed to avoid errors

When administering vaccines it is important to think about how they should be prepared and the choice of injection site, route and needle length. These factors should be considered carefully, as each one can affect both the immune response to the vaccine and the risk of local reactions.

Vaccine preparation
Vaccines should only be reconstituted and drawn up when required to avoid errors and maintain vaccine efficacy and stability.1 Most syringes are designed for immediate administration and not for vaccine storage. Vaccine components may interact with the plastic syringe components over time and reduce vaccine potency. Bacterial contamination and growth can also occur if immunisers pre-fill syringes with vaccines that do not contain antibacterials.

When reconstituting freeze-dried vaccines, only the diluent supplied should be used and the reconstituted vaccine should be given within the specified time period. Some vaccines, such as the MMR, rapidly lose potency following reconstitution. Only vaccines licensed to be mixed with other vaccines should be mixed together.

Unless supplied in a pre-filled syringe, a 21 G (green) needle should be used to draw up and add diluent to the vaccine. A new needle of a size appropriate to the individual patient should then be used to inject the vaccine. Before giving the vaccine, check that the colour and composition of the vaccine are as described in the Summary of Product Characteristics. Check the vaccine to ensure it is the correct product and dose for the patient and check the expiry date. All too often immunisers only check these details when they are recording vaccines given and discover the vaccine had already expired or they have given a paediatric dose to an adult.

Skin does not require cleansing before giving a vaccine unless it is visibly dirty; in which case it need only be washed with soap and water. If alcohol and other disinfecting agents are used, skin must be allowed to dry as these could inactivate live vaccines. It is not necessary to wear gloves unless there is likelihood of coming into contact with potentially infectious body fluids or you have open lesions on your hands. Soap and water or alcohol hand rub should be used to clean hands before preparing vaccines and between each patient contact.

Positioning the vaccine recipient
It is important to ensure that the vaccination site is completely exposed. Trying to reach under tight clothing is likely to result in the vaccine being given into the wrong place and at the wrong angle, thereby resulting in decreased immunogenicity of the vaccine and increased likelihood of a local reaction. It is also important to ensure that babies and young children are held very securely to avoid needlestick injuries and
vaccine spillage.

Vaccine administration
With the exception of BCG, oral typhoid and oral cholera vaccines, most vaccines should be given intramuscularly (IM) as this leads to a better immune response to the vaccine and reduces the chance of local reactions.2,3 Adjuvanted vaccines (Td/IPV) given subcutaneously (SC) or intradermally (ID) can cause irritation, induration, inflammation and granuloma formation.4 However, individuals with a bleeding disorder should receive their vaccines by deep SC injection to reduce the risk of bleeding.

Needle length
For IM injections, the needle needs to be long enough to ensure the vaccine is injected into muscle. A 25 mm needle length is preferable and suitable for all ages, with the only exceptions being pre-term or very small infants (for whom a 16 mm needle length is recommended) and larger adults (for whom a longer length (38 mm) may be required). An individual assessment should be made.

Injection site
The injection site is determined by the route to be used (IM or ID), the age and size of the patient, and the amount of vaccine to be injected. For infants under one year, the anterolateral aspect of the thigh is the preferred site as it provides a large muscle mass. For older infants and adults, the deltoid area of the upper arm is generally preferred but the anterolateral aspect of thigh can also be used.

Vaccines should not be given into the buttock due to the risk of sciatic nerve damage and the increased likelihood of injecting into fat rather than muscle which has been shown to reduce the immunogenicity of both hepatitis B and rabies vaccines.5-8
When two or more injections need to be administered at the same time, they should preferably be given into different limbs. If more than one injection needs to be given into the same limb, they should be given at least 2.5 cm apart and the site at which each vaccine was given should be recorded. With more vaccines being introduced into the schedule, immunisers need to be confident that administering two injections into one limb or several vaccines at one visit is not harmful and is in the best interests of the patient.

Injection technique
IM injections should be given with the needle at a 90º angle to the skin with the skin stretched flat, not bunched. It is not necessary to aspirate the syringe after the needle is put into the muscle as there are no large blood vessels present at the recommended injection sites. Although immunisers can aspirate if they are dexterous enough and prefer to do this, one study found that immunisation using a slow aspiration technique for giving DTaP/IPV/Hib vaccine to infants was significantly more acutely painful than a rapid injection technique without aspiration.9 The authors advocated that the rapid, no aspiration technique should be recommended for
routine IM injections.

Post vaccination
After vaccines have been administered, recipients should be observed for any immediate reactions. There is no specified time period for post-immunisation observation. However, the time it takes for the recipient to re-dress and for the immuniser to give immunisation advice, dispose of vaccine equipment and document vaccines given should provide an adequate observation period.


  1. Salisbury D, Ramsay M, Noakes K (eds). Immunisation against infectious disease. Available from:
  2. Ipp MM, Gold R, Goldback M et al. Adverse reactions to diphtheria, tetanus, pertussis-polio vaccination at 18 months of age: effect of injection site and needle length. Pediatrics 1989;83:679-82.
  3. Diggle L, Deeks, JJ, Pollard AJ. Effect of needle size on immunogenicity and reactogenicity of vaccines in infants: randomised controlled trial. BMJ 2006;333:571-4.
  4. National Center for Immunization and Respiratory Diseases. General recommendations on immunization: recommendations of the Advisory Committee on Immunization Practices. MMWR 2011;60(2):1-60.
  5. Piggot J. Needling doubts about where to vaccinate. BMJ 1988;297:1130
  6. Villarejo FJ, Pascaul AM. Injection injury of the sciatic nerve (370 cases). Child Nerv Syst 1993;9:229-32.
  7. Shaw FE Jr, Guess HA, Roets JM et al. Effect of anatomic injection site, age and smoking on the immune response to hepatitis B vaccination. Vaccine 1989;7:425-30.
  8. Fishbein DB, Sawyer LA, Reid-Sanden FL, Weir EH. Administration of human diploid-cell rabies vaccine in the gluteal area. N Engl J Med 318(2):124-5.
  9. Ipp M, Taddio A, Sam J et al. Vaccine related pain: randomized controlled trial of two injection techniques. Arch Dis Child 2007;8(92):1105-8.

Your comments (terms and conditions apply):

"Impossible to do with kids but good with adults. Seems to be losing favour" - Kirsty Armstrong

"There is no mention of the Ztrack method of vaccinating, which we are led to believe is the best practice method. What is the author's or anyone else's opinion on this method? I find it relatively easy, and nowhere near the number of patients who bleed afterwards" - Marilyn Whalley