Tips on reconstituting vaccines

It gets a bit more complicated when you move from providing flu vaccines to travel vaccines, on our courses we will always cover how to do this, but it takes practise! Some vaccines are supplied in a pre-filled syringe, others need to be reconstituted before use. Vaccines should be reconstituted when required, not in advance of an immunisation session, to avoid errors and maintain vaccine efficacy and stability

To reconstitute…….

…..follow these simple steps to help you

    • Only use the diluent supplied and note the time scale in which it must be used after dilution (often 1-4 hours)
  • A green needle (21G x 38mm (11/2 inch)) should be used to draw up the diluent and to inject it slowly into the ampoule containing the vaccine . Injecting diluent rapidly into the vaccine may cause frothing, which can affect the dilution and consequent potency of the vaccine; shaking the ampoule may have a similar effect
  • If the freeze-dried powder does not instantly dissolve in the diluent, gently rotate the ampoule until it dissolves.
    • Draw up the appropriate dose
    • Unless the vaccine is supplied in a pre-filled syringe with an attached needle, a new needle of a size appropriate to the individual patient should be used to inject the vaccine

Extra information –

-When drawing up from a glass ampoule, use a needle gauge no larger than 21G to eliminate the possibility of drawing up glass fragments.

-Where possible change a needle after it has passed through a rubber bung before administering the vaccine

– For quantities, less than 1ml use a graduated 1ml syringe

Appropriate infection control and aseptic techniques should be used at all times.


UK Needle Gauge and Length





 16mm or 25mm








We hope you found this a helpful reminder?

Written by Jane Lambert 13th April 2017