Adverse events following mRNA SARS-CoV-2 vaccination among U.S. nursing home residents

Background

The devastating impact of the SARS-CoV-2 pandemic prompted the development and emergency use authorization of two mRNA vaccines in early 2020. Vaccine trials excluded nursing home (NH) residents, limiting adverse event data that directly apply to this population.

Methods

To prospectively monitor for potential adverse events associated with vaccination, we used Electronic Health Record (EHR) data from Genesis HealthCare, the largest NH provider in the United States. EHR data on vaccinations and pre-specified adverse events were updated daily and monitored for signal detection among residents of 147 facilities who received the first dose of vaccine between December 18, 2020 and January 3, 2021. For comparison, unvaccinated residents during the same time period were included from 137 facilities that started vaccinating at least 15 days after the vaccinating-facilities.

Results

As of January 3, 2021, 8553 NH residents had received one dose of SARS-CoV-2 vaccine and by February 20, 2021, 8371 residents had received their second dose of vaccine; 11,072 were included in the unvaccinated comparator group. No significant associations were noted for neurologic outcomes, anaphylaxis, or cardiac events.

Conclusions

No major safety problems were detected following the first or second dose of the vaccine to prevent COVID-19 in the study cohort from December 18, 2020 through March 7, 2021.

Safety of pentavalent DTaP-IPV/Hib combination vaccine in post-marketing surveillance in Guangzhou, China, from 2011 to 2017

BACKGROUND

The DTaP-IPV/Hib combination vaccine can replace the acellular tetanus vaccine, polio vaccine, and the Haemophilus influenzae type B vaccine. Data on the safety of DTaP-IPV/Hib vaccines are required. We aimed to evaluate the safety of the vaccination program.

METHODS

Using the National Adverse Events Following Immunization (AEFI) surveillance system (CNAEFIS) in Guangzhou, China, a retrospective study was performed from May 11, 2011, to December 31, 2017. There were 376 cases of adverse events after vaccination with the DTaP IPV/Hib vaccine. The primary analysis indicators were the number of vaccines used, the number of AEFI reports received, and the reporting rate (per 100,000).

RESULTS

From May 1, 2011, to December 31, 2017, 516,000 doses of vaccine were inoculated, and 376 cases of adverse reactions were reported; the reporting rate was 72.8 per 100,000 vaccines. There were eight cases of serious AEFIs (1.5 per 100,000), with four cases of thrombocytopenic purpura (0.8 per 100,000); three cases of cyanosis of the lips, stiffness, and flexion of limbs, and convulsions (0.6 per 100,000); and one case of a high fever (0.2 per 100,000). The highest incidence of AEFIs occurred after the fourth dose (n = 207, 55.0%, 40.1 per 100,000), followed by the first dose (n = 81, 21.5%, 15.7 per 100,000), second dose (n = 48, 12.8%, 9.3 per 100,000) and third dose (n = 40, 10.6%, 7.7 per 100,000). The AEFI incidence was higher after injection of the vaccine into the deltoid muscle of the upper arm (n = 276, 73.4%, 53.5 per 100,000) than after injection of the vaccine into the thigh (n = 100, 26.6%, 19.4 per 100,000). There was a significant difference between AEFIs after injection into the deltoid of the upper arm deltoid and the thigh (x² = 164.8, P < 0.05).

CONCLUSIONS

Most of the reported AEFIs after DTaP-IPV/Hib vaccination are not serious. There were four cases of TP in this study; vaccination may be a rare cause of thrombocytopenic purpura.

On the contextual nature of vaccine safety monitoring: Adverse events reporting after HPV-vaccination in Denmark, 2015

BACKGROUND

In 2013-15, Denmark experienced an increase in reported suspected adverse events following vaccination (AEFI) against human papilloma virus (HPV). Dedicated centres ("One Access") were established in order to standardize management of patients who experienced medically unexplained physical symptoms after HPV vaccination. Since One Access was targeted patients with suspected AEFI after HPV vaccination, we used this opportunity to estimate completeness in AEFI reporting to the Danish Medicines Agency (DMA), and explore the topic of AEFI reporting from the perspective of physicians working at the centres to better understand health professionals' reporting behaviour.

METHODS

The study consisted of a quantitative and a qualitative part. In the quantitative analysis, we used the Danish civil registry number to merge a line-list of all One Access patients referred in 2015 with total number of patients who had reported suspected serious AEFI following HPV vaccination to the DMA in the years 2009-2015. We conducted four semi-structured interviews with doctors representing three out of five regions. The Theoretical Domains Framework together with empirical data from two clinical fieldtrips guided the formation of the qualitative study.

RESULTS

Among 1577 One Access patients, only 404 (26%) were reported to the DMA. We found significant regional differences in reporting completeness (p < 0.001) and differences between regions when looking at reporters' backgrounds (healthcare professionals vs non-professionals; p = 0.004). We identified several factors of importance for reporting behaviour amongst physicians, mainly under the domains of Knowledge, Motivation & Goals, and Environmental Context.

CONCLUSIONS

Despite an official aim of homogenous case management, reporting of suspected AEFI was incomplete with large regional differences. The qualitative study corroborated that reporting behaviour was contextual. This observation represents an important caveat in interpreting data from AEFI reporting, in particular when these data are used for research or policymaking.

Vaccine monitoring systems: A potential model for medications in pregnancy

Multiple vaccine safety systems contribute to monitor and assess the safety of vaccines given to pregnant women and their offspring. This article presents a review of the strengths and limitations of several national vaccine safety systems. The review concludes that the present framework of vaccine safety systems offers lessons to be learned toward the design of a system for monitoring and assessing the safety of medications administered to pregnant women in clinical practice and research.