{{cite journal | last1=Rashid | first1=A. | author2=K Rasheed | author3=M. Akhtar | year=2009 | title=FACTORS INFLUENCING VACCINE EFFICACY - A GENERAL REVIEW | journal=Journal of Animal and Plant Sciences | volume=19 | issue=1 | pages=22-25 | issn=1018-7081 | eissn=2309-8694 | publisher=Pakistan Agricultural Scientists Forum | url=https://thejaps.org.pk/AbstractView.aspx?mid=2009-JAPS-112}}