Pig farming

Store vaccines correctly for maximum efficacy

How vaccines are stored and managed before use is unlikely to be a high priority on most pig units, but according to Zoetis UK’s National Veterinary Manager, Ruth Vernon, the potential losses due to incorrect storage can be huge.

“A favourite saying of mine is the most expensive treatment a farmer will ever use is the one that doesn’t work,” she says, “and a vaccine damaged, or denatured, because of incorrect storage is highly likely not to work!”

The problem is that vaccines are proteins, and if you change their structure you’ll alter the pig’s immune response to them.

“The response will be altered if you denature the vaccine with heat or cold, and the animal is unlikely to respond in the expected way,” Ruth adds. “All the trial work on the vaccine will have been done using the recommended storage conditions, and if you deviate from that, you risk adversely affecting the quality of the product and the immune response you get.

Most vaccines should be stored at fridge temperature, between 2°C – 8°C, but it’s important to check the storage conditions and follow the advice given on the manufacturer’s data sheet.

“Generally, freezing a vaccine completely denatures it, and while some vaccines can cope with being at room temperature for a while, it’s best to store then properly at all times for the best results,” Ruth says. “Once a vaccine has been compromised, you can’t reverse it – and you can’t tell if it’s been compromised simply by looking at it.

“Laboratory testing of the vaccine may indicate whether it still works, but that’s likely to cost more than the vaccine’s worth.”

The only time vaccines should be removed from the fridge is when they are about to used, and for most pigs they should be administered more or less immediately.

“The only exception is when vaccinating young animals,” says Ruth Vernon. “Some manufacturers recommend bringing the vaccine up to room temperature before administration to limit the shock of giving a very cold injection.”

Zoetis UK has produced a Vaccine Storage Guide with advice on setting up your fridge correctly and storing veterinary medicines appropriately. It includes the guidance shown below.


  • Nominate a person who’s responsible for managing both the vaccine inventory and the correct storage and use of medicines.
  • Maintain a vaccine inventory that logs the name, manufacturer, quantity, batch number, expiry date, maximum number of broachings per vial (if applicable) and date of purchase.
  • Check the temperature inside the shipping box when it arrives, and immediately refrigerate the vaccines.


  • Keep vaccines in a standard-sized fridge, or preferably a high-quality pharmaceutical fridge.
  • Don’t keep vaccines in the fridge door, against the walls or against the cold air inlet of the fridge (this could freeze the vaccines, rendering them unusable).
  • Don’t overstock the fridge.
  • Store vaccines in their original packaging.
  • Read and follow the manufacturer’s recommendations for each vaccine or medicine as they may be product specific.
  • Stack vaccines by type, and rotate the stock so the batch with the earliest expiry date is used first. Remember, FIRST-IN/FIRST-OUT!
  • Store jugs or bottles of water in the vaccine refrigerator to help maintain a steady temperatures. Mark these “DO NOT DRINK”.
  • Don’t store vaccines alongside food for human consumption.


  • Keep a good-quality min/max thermometer in the vaccine storage fridge.
  • Maintain the fridge between 2.0 to 8.0 Celsius; aim for 4.0 Celsius. Record the maximum and minimum temperatures the fridge has reached and reset the thermometer every day.
  • If the temperature is, or has been, above or below the recommended range, inform the farm manager and get the appliance repaired if necessary.
  • Regularly check the fridge’s door seals.
  • Ensure that all staff members close the fridge door tightly after opening, and don’t leave the door open unless required to do so. Constant opening of the door can cause wide temperature fluctuations.
  • Mark the fridge’s electrical outlet with “DO NOT UNPLUG” signs.


  • Have a written protocol addressing power outages.
  • Consider moving vaccines to a place where they can be maintained at the appropriate temperature.
  • If moving isn’t an option, don’t open the fridge until power is restored.
  • As soon as power is restored, record the temperature in the fridge and the duration of the outage.
  • Mark the affected vaccines so they can be easily identified. Don’t discard. Call the vaccine manufacturer for guidance regarding whether the vaccines can still be used.

Zoetis UK’s Vaccine Storage Guide is available by requesting via email - pigteamuk@zoetis.com

For further information please contact please contact Zoetis UK Limited, First Floor, Birchwood Building, Springfield Drive, Leatherhead KT22 7LP. www.zoetis.co.uk. Customer Support: 0845 300 8034. Use medicines responsibly (www.noah.co.uk/responsible). Date of preparation: February 2020. MM-08441