Table 3. Results of the application of random effects models to the different levels of the factor moderators used in this meta-analysis.

Moderator	Level	Trials in the marginal meta-analysis	logRR (95% CI)
Vaccine type	Self-fabrication	Gonzaléz et al. (1989), Nordhaug et al. (1994), McClure et al. (1994), Watson et al. (1996-1), Watson et al. (1996-2), Tenhagen et al. (2001), Wilson et al. (2007), Slobodanka et al. (2010), Magaš et al. (2013), Sayed et al. (2016), Gorden et al. (2018-1), Gorden et al. (2018-2)	0.70 (0.51, 0.94)
	Commercial vaccine	Keskin et al. (2007), Morimoto et al. (2011), Maia et al. (2013), Bradley et al. (2015-1), Tashakkori et al. (2019)	1.07 (0.94, 1.22)
Vaccination timing	Before calving	Gonzaléz et al. (1989), Nordhaug et al. (1994), McClure et al. (1994), Watson et al. (1996-1), Watson et al. (1996-2), Tenhagen et al. (2001), Wilson et al. (2007), Slobodanka et al. (2010), Magaš et al. (2013), Sayed et al. (2016), Gorden et al. (2018-1), Keskin et al. (2007), Morimoto et al. (2011), Maia et al. (2013), Bradley et al. (2015-1), Tashakkori et al. (2019)	0.86 (0.72, 1.03)
	After calving	Gorden et al. (2018-2), Bradley et al. (2015-2)	1.72 (1.34, 2.21)
Type of animal	Heifers	Nordhaug et al. (1994), Watson et al. (1996-2), Tenhagen et al. (2001)	0.94 (0.75, 1.18)
	Multiparous	Gonzaléz et al. (1989), Watson et al. (1996-1), Wilson et al. (2007), Slobodanka et al. (2010), Magaš et al. (2013), Tashakkori et al. (2019)	0.70 (0.37, 1.31)
	Both together	McClure et al. (1994), Sayed et al. (2016), Gorden et al. (2018-1), Gorden et al. (2018-2), Keskin et al. (2007), Morimoto et al. (2011), Maia et al. (2013), Bradley et al. (2015-1)	0.91 (0.73, 1.13)

logRR: Logarithm of the risk ratio; CI: Confidence interval.