Keyword Analysis & Research: when did the definition of vaccine change

Keyword Analysis

Keyword	CPC	PCC	Volume	Score	Length of keyword
when did the definition of vaccine change	1.25	0.2	6381	37	41
when	0.06	0.7	5422	15	4
did	0.69	1	4883	36	3
the	0.1	0.7	2963	53	3
definition	1.82	0.9	6531	71	10
of	1.52	0.4	1746	37	2
vaccine	0.13	0.8	7690	77	7
change	0.6	0.4	7339	85	6

Keyword	CPC	PCC	Volume	Score
when did the definition of vaccine change	2	0.3	4705	7
was the definition of a vaccine changed	0.9	0.8	4727	21
when did cdc change vaccine definition	1.86	0.8	2868	56
has the definition of vaccine changed	0.33	0.8	8943	16
when was the definition of vaccine changed	1.02	0.3	4913	53
why did they change the definition of vaccine	1.56	0.6	4818	94
vaccine definition changes	1.64	1	1657	14
cdc vaccine definition change	0.98	0.8	7346	94
did the definition of vaccine change	1.89	0.7	2205	33
who changed the definition of a vaccine	0.32	1	9450	75
vaccine definition changed to include mrna	0.99	0.9	5407	97