Table 2. Cases of invasive pneumococcal disease averted by PCV13, United States, 1997–2019*.

Year	No. observed				No. expected				Cumulative cases averted		Difference in non-PCV13 serotype cases†
	All	PCV13 serotypes	Non-PCV13 serotypes		All	PCV13 serotypes	Non-PCV13 serotypes		All	PCV13 serotypes
1997	15,543	14,439	1,104		15,543	14,439	1,104		NA	NA	NA
1998	18,136	16,848	1,288		18,136	16,848	1,288		NA	NA	NA
1999	17,785	16,839	945		17,785	16,839	945		NA	NA	NA
2000	15,306	13,808	1,498		17,364	16,178	1,186		2,057	2,369	−312
2001	7,887	6,561	1,325		17,689	16,481	1,208		11,860	12,289	−429
2002	4,596	3,109	1,487		17,899	16,677	1,223		25,164	25,857	−693
2003	4,577	2,743	1,834		17,874	16,653	1,221		38,460	39,767	−1,307
2004	4,192	2,374	1,818		18,013	16,783	1,230		52,281	54,175	−1,894
2005	4,336	2,589	1,747		18,101	16,864	1,236		66,046	68,450	−2,405
2006	4,219	2,592	1,627		18,130	16,891	1,238		79,956	82,750	−2,793
2007	4,537	3,019	1,518		18,372	17,118	1,255		93,792	96,848	−3,057
2008	4,221	2,635	1,585		18,562	17,294	1,268		108,133	111,507	−3,374
2009	4,449	3,037	1,412		18,358	17,104	1,254		122,043	125,575	−3,532
2010	4,014	2,626	1,388		18,074	16,839	1,235		136,103	139,788	−3,685
2011	2,515	805	1,710		18,085	16,850	1,235		151,674	155,833	−4,160
2012	1,870	400	1,470		18,009	16,779	1,230		167,813	172,213	−4,400
2013	1,988	397	1,591		17,916	16,692	1,224		183,741	188,508	−4,766
2014	1,790	397	1,392		17,963	16,736	1,227		199,914	204,846	−4,932
2015	1,856	398	1,457		18,053	16,820	1,233		216,112	221,268	−5,156
2016	906	398	507		18,068	16,834	1,234		233,275	237,703	−4,429
2017	1,391	398	993		17,934	16,709	1,225		249,818	254,015	−4,197
2018	1,382	396	986		17,752	16,539	1,213		266,188	270,158	−3,970
2019	1,382	396	986		17,752	16,539	1,213		282,558	286,302	−3,744

*Values are rounded to the nearest whole numbers. NA, not applicable; PCV13, 13-valent pneumococcal conjugate vaccine. 
†Negative values indicate greater number observed than would be expected.