Originally published June 14, 2023 5:53 am PDT
A pre-print study published last week in Epidemiology and Health confirms that adverse events caused by the COVID-19 vaccine are not being reported.
The study authors from South Korea and Canada examined the reporting rates of adverse events following immunization (AEFIs) to a spontaneous reporting system (SRS) and its predictors among individuals with AEFIs after COVID-19 vaccination.
They analyzed a cross-sectional, web-based survey conducted from December 2 to 20, 2021, and recruited 2,993 participants who had completed a primary COVID vaccination series more than 14 days prior.
“Reporting rates were calculated by dividing the number of participants who reported AEFIs to the SRS by the total number of participants who experienced AEFIs,” the authors explained. “We estimated adjusted odds ratios (AORs) using multivariate logistic regression to determine factors associated with spontaneous AEFI reporting.”
The majority of patients experienced adverse events following immunization after both the first (90.9%) and second (88.7%) vaccine doses, with reporting rates of 11.6% and 12.7% respectively.
Moderate to severe AEFIs were reported by 3.3% and 4.2% of participants after the first and second doses, with reporting rates of 50.5% and 50.0% respectively.
Spontaneous reporting of AEFIs after COVID vaccination was connected especially with “younger age, female sex, moderate to severe AEFIs, comorbidities, history of allergic reactions, and vaccine type.”
Specifically, spontaneous reporting was more common among women (Adjusted Odds Ratios [AOR]=1.54; 95% CI, 1.31-1.81), individuals with moderate to severe AEFIs (AOR=5.47; 95% CI, 4.45-6.73), those with comorbidities (AOR=1.31; 95% CI, 1.09-1.57).
Spontaneous reporting is also more common among those with a history of severe allergic reactions (AOR=2.02; 95% CI, 1.47-2.77), and those who received Moderna’s jab (AOR=1.25; 95% CI, 1.05-1.49) or the Jenner Institute/University of Oxford formulation (AOR=1.62; 95% CI, 1.15-2.30).
Older individuals were less likely to report AEFIs (AOR=0.98; 95% CI, 0.98-0.99 per 1-year age increment).
The authors conclude by confirming that there is a problem regarding coronavirus vaccine-linked injuries, namely that they are not being reported to authoritative health agencies.
“AEFI under-reporting should be considered when delivering information to the community and in public health decision-making,” they write.
The study acknowledges that, because of this problem, vaccine adverse event reporting systems fail to “provide accurate estimates of the rate of” these injuries, making it impossible to “assess a causal relationship between vaccination and adverse events.”
It ends by stating that “further in-depth studies are needed to elucidate the causality.”
A 2010 analysis submitted to the Agency for Healthcare Research and Quality at the U.S. Department of Health and Human Services (DHHS) confirmed that fewer than 1% of vaccine adverse events that do occur are ever reported.
“Adverse events from drugs and vaccines are common, but underreported,” write the analysis authors, adding that “[a]lthough 25% of ambulatory patients experience an adverse drug event, less than 0.3% of all adverse drug events and 1-13% of serious events are reported to the Food and Drug Administration (FDA).”
“Likewise, fewer than 1% of vaccine adverse events are reported,” the analysis emphasized.
Moreover, a 2012 Springer Link systematic review found “evidence of significant and widespread under-reporting” of adverse drug reactions.
The review authors looked at “37 studies using a wide variety of surveillance methods were identified from 12 countries” and “generated 43 numerical estimates of under-reporting.”
They discovered that the median under-reporting rate across the 37 studies was 94% (interquartile range 82–98%).
However, the authors found that five of the ten “general practice studies provided evidence of a higher median under-reporting rate for all ADRs compared with more serious or severe ADRs (95% and 80%, respectively).”
In five of the eight hospital-based studies, the median under-reporting rate for more serious or severe ADRs remained high, at 95%.
Even though the median under-reporting rate was lower for 19 studies investigating specific serious/severe ADR-drug combinations, it was still high at 85%.
