IPD Quarterly Report: Oct-Dec 2021

The total number of IPD cases in 2021 relative to 2019 were comparable through Q3 (365 and 385 annual cases through Q3 2019 and Q3 2021, respectively), though COVID-19 control measures were re-introduced in Q4 2021 and likely affected the number of IPD cases in late 2021. Throughout 2021, the rates of IPD have remained relatively stable for 5-64 year olds. The rate of IPD among those 2-4 years old and 65 or older through Q4 2021 was slightly higher than the rate at the end of 2020. However, for children under 2 the rate of IPD through Q4 2021 was the highest since 2012. The rate of serotype 19A for children under 2 years steadily increased since 2017. The rate of 19A in 2021 among children under 2 years and for children 2-4 years old was the highest since before PCV10 was first introduced in 2011. The rates of serotype 19A for 2021 among 65 or older was the highest since 2015.