The role of a single-shot higher-valency pneumococcal vaccine in overcoming challenges regarding invasive pneumococcal disease in Hong Kong

Burden of invasive pneumococcal disease in Hong Kong Invasive pneumococcal disease has been a statutorily notifiable disease in Hong Kong since January 2015.8Between 2015 and 2019, the Centre for Health Protection recorded a median of 187 (range: 162-190) IPD cases per year; the emergence of COVID-19 in 2020 led to a dramatic decrease in the number of IPD cases in Hong Kong (Fig 1).3 However, the current IPD burden is severely underestimated because of underdiagnosis, and a high index of suspicion for IPD is a central aspect of differential diagnosis. Because the clinical symptoms of IPD overlap with the symptoms of other respiratory illnesses, inexperienced physicians may experience challenges regarding specimen collection (ie, samples may be inappropriately or inadequately collected); such challenges contribute to the underutilisation of diagnostic tests and underreporting of IPD. Because S pneumoniae is transmitted by direct contact with respiratory secretions from patients with IPD and from healthy carriers,2 9 public health measures (eg, mask wearing, social distancing, travel restrictions, and quarantine) that were implemented to prevent the transmission of severe acute respiratory syndrome coronavirus 2 also reduced the spread of S pneumoniae; thus, the number of IPD cases has decreased since the beginning of 2020 (Fig 1).3 As Hong Kong emerges from the COVID-19 pandemic, the gradual relaxation of public health intervention measures is expected to result in an increased number of IPD cases. [...]seasonality could contribute to a sudden increase in IPD cases because respiratory diseases (eg, pneumococcal infection and influenza) are generally more prevalent during winter and early spring.10 11Notably, Israel experienced a nationwide outbreak of S pneumoniae serotype 2 between 2015 and 2019, despite the availability of vaccination programmes.12Such outbreaks highlight the need to formulate effective strategies for early disease prevention. Overcoming challenges in Hong Kong and implementing preventive strategies against invasive pneumococcal disease The government and physicians play key roles in promoting pneumococcal vaccination and improving vaccine uptake, particularly among older adults. Because the perceived low burden of IPD may reduce the rate at which physicians recommend vaccination for their patients,30 there is a need to improve physician awareness regarding IPD and the benefits of pneumococcal vaccines for individuals with an increased ri