Keyword Analysis & Research: when was the definition of vaccine changed

Keyword Analysis

Keyword	CPC	PCC	Volume	Score	Length of keyword
when was the definition of vaccine changed	0.78	0.2	3285	76	42
when	0.57	0.3	2124	100	4
was	1.87	1	4992	65	3
the	1.38	0.2	3534	70	3
definition	1.93	0.8	1951	58	10
of	0.26	0.9	6699	57	2
vaccine	0.6	0.5	1044	58	7
changed	0.82	0.1	1030	96	7

Keyword	CPC	PCC	Volume	Score
when was the definition of vaccine changed	0.88	0.9	7512	42
was the definition of a vaccine changed	1.88	1	6431	4
has the definition of vaccine changed	0.86	0.6	2829	29
who changed the definition of a vaccine	1.33	0.1	5653	96
why was the definition of vaccine changed	1.84	0.6	8568	80