Investigating adverse events following immunisation with pneumococcal polysaccharide vaccine using electronic General...

Area of Science:

• Pharmacovigilance
• Immunization Safety
• Public Health Surveillance

Background:

• Australian authorities advised against repeat 23-valent pneumococcal polysaccharide vaccine (23vPPV) doses in healthy adults in 2011.
• This recommendation followed an increase in reported severe vaccine-related injection site reactions.

Purpose of the Study:

• To evaluate the utility of primary care electronic medical record (EMR) data.
• To assess the validity and capability of EMR data for detecting adverse event signals retrospectively.

Main Methods:

• Utilized data from the General Practice Research Network (GPRN) in Australia.
• Extracted data on vaccinations (23vPPV and influenza) and adverse reactions from 2002 to 2012.
• Assessed increases in reaction rates using Poisson distribution and 95% confidence intervals.

Main Results:

• Over 95,000 23vPPV administrations and 680,000+ influenza vaccine doses were recorded.
• Observed local reaction rates for 23vPPV in early 2011 were not significantly different from historical averages.
• The system could have detected a 3-fold increase over background levels.

Conclusions:

• General Practitioner (GP) consultation data did not corroborate the passive surveillance signal of increased local reactions.
• The observed signal of adverse events was likely artefactual.
• GP EMR data offers a cost-effective method for validating pharmacovigilance signals, with potential for expansion.