. 2019 Dec 16;71(12):3096–3102. doi: 10.1093/cid/ciz1198

Table 2.

Association of Pseudovirus Neutralization and Neuraminidase Inhibition Antibody Titers With Risk of H3N2 Infection

Influenza Cases	Control Group	Antigen	OR for PVN IC₉₅ Titers			OR for NAI IC₅₀ Titers
			OR	95% CI	P Value	OR	95% CI	P Value
H3N2⁺, n = 29	H3N2⁻ and housing controls, n = 106	SC16	0.59	.45–.77	.0001	0.68	.53–.87	.0028
		TX12	0.67	.52–.87	.0023	0.62	.47–.82	.001
		WY03	0.91	.66–1.24	.532	0.65	.47–.90	.009
		MSC99	0.81	.61–1.09	.162	Not done
		CA09 (H1N1)	1.05	.83–1.34	.681	0.99	.80–1.22	.91
H3N2⁺, n = 29	H3N2⁻, n = 29	SC16	0.60	.41–.86	.0059	0.87	.63–1.20	.391
H3N2⁺, n = 29	Housing controls, n = 77	SC16	0.58	.44–.77	.0002	0.62	.47–.82	.0007
H3N2⁺ and pneumonia, n = 12	H3N2⁺, no pneumonia, n = 17	SC16	0.48	.25–.91	.0249	1.12	.74–1.69	.597
Influenza Cases	Control Group	Antigen	OR for Alternative PVN IC ₅₀ Titers			OR for Alternative NAI IC ₉₅ Titers
			OR	95% CI	P Value	OR	95% CI	P Value
H3N2⁺, n = 29	H3N2⁻ and housing controls, n = 106	SC16	0.68	.51–.90	.0074	0.67	.49–.93	.0175

A P value <.05 is considered significant. H3N2⁺ tested positive by reverse transcription polymerase chain reaction (RT-PCR) for A/H3N2 influenza. H3N2⁻ tested negative by RT-PCR for A/H3N2 influenza. Pneumonia confirmed by chest X ray when clinically indicated. Virus antigens: SC16 = A/South Carolina/NHRC 75458/2016 (H3N2); MW99 = A/Moscow/20/99 (H3N2); WY03 = A/Wyoming/03/03 (H3N2); TX12 = A/Texas/50/12 (H3N2); and CA09 = A/California/7/2009 (H1N1).

Abbreviations: CI, confidence interval; IC₅₀, titer that inhibited 50% of infection by the antigen tested for PVN or NA activity for NAI; IC₉₅, titer that inhibited 95% of infection by the antigen tested for PVN or NA activity for NAI; NAI, neuraminidase inhibition; OR, odds ratio; PVN, pseudovirus neutralization.