Post-vaccination complications: abscesses

Abscess – aseptic (sterile) or infectious – a localized formation with liquid contents in the soft tissues at the site of vaccine administration.

Abscess aseptic (sterile):

develops, as a rule, at later stages (later than 7 days from the moment of vaccination)
abscess material – aseptic nature (no infection);
there are no local and general signs of inflammation;
there are no changes on the background of antibiotic and therapy.

Sterile abscesses occur with non-live vaccines containing aluminum salts (~1 per 100,000 doses) and represent local inflammation. They are more likely to occur when the vaccine is missing or not shaken properly before use, when administered superficially, or when using a vaccine that has been frozen.

When vaccinated with BCG, a cold abscess may be the result of an incorrect technique for administering the vaccine (subcutaneous instead of intradermal).

Abscess – infectious:

develops, on average, within seven days after injection;
bacteriological examination revealed gram-positive flora (during sowing or in a smear);
and / or there is one or more signs of localized inflammation (redness, pain, soreness with light touch, increased tissue temperature at the injection site);
and improved with antibiotic therapy.