We observed a sudden and rapid increase in rare invasive pneumococcal disease serotype 7C, from an annual average of 3 cases during 2000–01 through 2015–16 to 29 cases in 2016–17. The increase was caused almost entirely by clonal expansion of sequence type 177, previously associated with vaccine serotype 19F.
Bibliographical noteFunding Information:
Disclaimers: C.S. and N.K.F. as employees of Public Health England’s Respiratory and Vaccine Preventable Bacteria Reference Unit, have received research funding from Pfizer and GlaxoSmithKline but receive no personal remuneration. The Immunisation, Hepatitis, and Blood Safety Department has provided vaccine manufacturers with postmarketing surveillance reports on vaccine-preventable diseases, including pneumococcal infections, which the companies are required to submit to the UK Licensing Authority in compliance with their Risk Management Strategy. A cost recovery charge is made for these reports. All other authors declare no competing interests.