Using EHRs To Track Vaccine Surveillance

The United States is trending up in SARS-CoV-2 cases. In the last two weeks, we’ve seen an over 50% increase in cases of COVID-19. This likely represents a significant undercounting too, as many are taking at-home antigen tests that are not likely to be recorded. As the United States, like so many countries, struggles to stay focused on this pandemic, the importance of vaccinations and boosters grows.

Since the development and availability of vaccines, 77% of Americans have gotten at least one dose and 66% are fully vaccinated. More concerning though, is that less than half of Americans have gotten their booster dose according to the Centers for Disease Control and Prevention (CDC). With such low numbers of boosted individuals who are eligible, it becomes increasingly important to proactively address concerns, etc. One such piece is the safety of the third dose of mRNA vaccines. A new study published in JAMA sought to use electronic health records (EHR) to perform surveillance of the safety of three doses of the COVID mRNA vaccines.

Utilizing EHR from December 2020 to October 2021 across multiple Mayo Clinic sites in various states within the United States, the team assessed the HER of 47,999 people who received three doses of the mRNA vaccines. The research team broke them further into two cohorts based on vaccine manufacturer which served as their own control group. EHR-based reports of vaccine-associated adverse events were then assessed and risk was quantified if such events occurred within 14 days of each vaccine dose. The authors reported a range of outcomes – “Among 47 999 individuals who received 3-dose COVID-19 mRNA vaccines, 38 094 individuals (21 835 [57.3%] women; median [IQR] age, 67.4 [52.5-76.5] years) received BNT162b2 (79.4%) and 9905 individuals (5099 [51.5%] women; median [IQR] age, 67.7 [59.5-73.9] years) received mRNA-1273 (20.6%). Reporting of severe adverse events remained low after the third vaccine dose, with rates of pericarditis (0.01%; 95% CI, 0%-0.02%), anaphylaxis (0%; 95% CI, 0%-0.01%), myocarditis (0%; 95% CI, 0%-0.01%), and cerebral venous sinus thrombosis (no individuals) consistent with results from earlier studies. Significantly more individuals reported low-severity adverse events after the third dose compared with after the second dose, including fatigue (2360 individuals [4.92%] vs 1665 individuals [3.47%]; P < .001), lymphadenopathy (1387 individuals [2.89%] vs 995 individuals [2.07%]; P < .001), nausea (1259 individuals [2.62%] vs 979 individuals [2.04%]; P < .001), headache (1185 individuals [2.47%] vs 992 individuals [2.07%]; P < .001), arthralgia (1019 individuals [2.12%] vs 816 individuals [1.70%]; P < .001), myalgia (956 individuals [1.99%] vs 784 individuals [1.63%]; P < .001), diarrhea (817 individuals [1.70%] vs 595 individuals [1.24%]; P < .001), fever (533 individuals [1.11%] vs 391 individuals [0.81%]; P < .001), vomiting (528 individuals [1.10%] vs 385 individuals [0.80%]; P < .001), and chills (224 individuals [0.47%] vs 175 individuals [0.36%]; P = .01).”

Ultimately, the authors noted that there wasn’t a significant difference in reporting of severe adverse events but there was a significant increase in reporting for many of the most common low-severity adverse events after receiving the third dose. While these are low-severity events, they can be deterrents for those nervous about symptoms unable to take time off.

More wrap around services and support for those getting their third dose will be critical. More importantly, communicating that while they are more common, such outcomes are brief and not severe, is important to building trust and transparency in vaccines and public health overall.