Table 5. Summary of Pooled Analysis Results and Statistical Significance.

RCT= Randomized Controlled Studies; OBS=Observational Studies; NNT- Number needed to treat; PI/UV=previously infected, unvaccinated; PI/V=previously infected, vaccinated; RR-risk ratio; AR- absolute risk

	NPI/V vs. PI/UV	PI/UV vs. PI/V
	RR	RR
Pool	AR	AR
RCTs	P>0.05	P>0.05
	P>0.05	v P>0.05
OBS	Favors Natural Immunity	Favors Vaccination
	Favors Natural Immunity	P>0.05
Total	P>0.05	Favors Vaccination
	Favors Natural Immunity	Favors Vaccination