A PHC medical officer wants to give pulse polio immunization. The following finding in the Vaccine Vial Monitor (VVM) indicates that the vaccine should not be used:
c. Inner square matches the color of the outer circle(Ref: Nelson's 20/e p 1561, Ghai 8/e p 190-194)Interpretation of the color change of VVM is as follows:Inner square is white, or lighter than outer circle: If the expiry date has not passed, vaccine can be usedInner square matches color of outer circle or is darker than outer circle: Vaccine should be discarded, regardless of the expiry date.
Inner square is white, outer circle is blue
Inner square is blue but lighter than outer circle
Inner square matches the color of the outer circle
Inner square is lighter than outer circle
Immunization