Impact of Pneumococcal Conjugate Vaccines on Antibiotic-Nonsusceptible Invasive Pneumococcal Disease in the United States

Antibiotic-nonsusceptible invasive pneumococcal disease (NS-IPD) incidence decreased after 7- and 13-valent pneumococcal conjugate vaccine (PCV) introduction in the United States. Expanded valency PCVs recently recommended for adult use could contribute to further reductions in NS-IPD. Background Antibiotic-nonsusceptible invasive pneumococcal disease (NS-IPD) incidence declined dramatically in the United States after introduction of pneumococcal conjugate vaccines (PCVs) into the infant immunization schedule (7-valent PCV7 in 2000, replaced by the 13-valent PCV13 in 2010). We evaluated the long-term impact of PCVs on NS-IPD. Methods We identified IPD cases through the Centers for Disease Control Active Bacterial Core surveillance during 1998-2018. Isolates intermediate or resistant to >= 1 antibiotic class were classified as nonsusceptible. We calculated annual rates of IPD (cases per 100 000 persons). Results From 1998 through 2018, NS-IPD incidence decreased from 43.9 to 3.2 among children <5 years and from 19.8 to 9.4 among adults >= 65 years. Incidence of vaccine-type NS-IPD decreased in all age groups, whereas incidence of nonvaccine type (NVT) NS-IPD increased in all age groups; the greatest absolute increase in NVT NS-IPD occurred among adults >= 65 years (2.3 to 7.2). During 2014-2018, NVTs 35B, 33F, 22F, and 15A were the most common NS-IPD serotypes. Conclusions Nonsusceptible IPD incidence decreased after PCV7 and PCV13 introduction in the United States. However, recent increases in NVT NS-IPD, most pronounced among older adults, have been observed. New higher valency PCVs containing the most common nonsusceptible serotypes, including 22F and 33F, could help further reduce NS-IPD.

Automated summary

The incidence of antibiotic-nonsusceptible invasive pneumococcal disease (NS-IPD) has decreased in the United States after the introduction of 7- and 13-valent pneumococcal conjugate vaccines (PCVs). However, there has been an increase in nonvaccine type NS-IPD, particularly among older adults. The use of higher valency PCVs containing the common nonsusceptible serotypes could help further reduce NS-IPD.