A new report from the U.S. Centers for Disease Control and Prevention (CDC) shows relatively low rates of adverse events from the 2019 coronavirus infection vaccine (COVID-19).
In total, between December 14 and January 13 more than 13.7 million doses of vaccine had been administered and 6994 reports of adverse events following vaccination. Of the adverse events, 6354 (90.8%) were deemed non-adverse and 640 (9.2%) were considered adverse.
To monitor vaccine safety and report adverse events, the CDC relies on the Vaccine Adverse Event Reporting System (VAERS), a non-invasive and v-safe reporting system, an active monitoring system.
Harmful incidents
The most common side effects were headache (22.4%), fatigue (16.5%), and hypothermia (16.5%). 113 deaths were also recorded for VAERS, including 78 (65%) among individuals in long-term care facilities. The median age of vaccine recipients reported in VAERS was 42, and 5505 (78.7%) of the reported adverse events occurred in women.
However, the CDC said the information available from death certificates, autopsy reports, medical records, and clinical descriptions from reports of VAERS and health care providers did not suggest any causal relationship between COVID-19 vaccination and death.
The report also identified rare cases of anaphylaxis after we received both vaccines, with 4.5 reported cases of anaphylaxis per million vaccine doses given.
In addition, for the individuals who received both doses of the Pfizer-BioNTech vaccine, the v-safe system was adversely affected more frequently after the second dose.
The authors also identified 6844 (97.9%) adverse events from individuals not living in long-term care facilities, 5533 (80.8%) from the Pfizer-BioNTech vaccine and 1311 (19.2%) in individuals half received the Moderna vaccine.
“The initial safety profiles following the authorization of the two COVID-19 vaccines currently in use did not show evidence of unforeseen adverse events,” the CDC says. “These data provide reassurance and useful information on what healthcare providers and vaccine recipients would expect after immunization.”
VAERS is collaborated with the CDC and the U.S. Food and Drug Administration (FDA). Adverse effect reports to VAERS are followed up with direct outreach, including telephone calls listed in the VAERS report to gather additional clinical details and medical records.
In December, the FDA issued Emergency Use Regulations (EUA) for both the Pfizer-BioNTech BNT162b2 vaccine and the Moderna mRNA-1273 vaccine.
Pfizer
In the FDA-assessed risk-benefit assessment of BNT162b2, they found an overall benefit of a lower risk of COVID-19 at least 7 days after a two-dose vaccination schedule in individuals with no prior history of SARS-CoV infection. -2.
They also assessed benefit that was consistent across subgroups according to age, race, gender, and comorbidity.
In observed risks, they noted the high rate of local and systemic adverse reactions, possible adverse events associated with the vaccine including lymphadenopathy, limited data among observed adolescents aged 16–17 years, with limited follow-up time, as well as risk assessment of pregnant women.
Moderna
The mRNA-1273 is coded for the stable prefusion form of the SARS-CoV-2 Spike S protein, a protein complex essential for membrane fusion and host cell disease. The vaccine was created in collaboration between Moderna and researchers from the Vaccine Research Center at the National Institute of Infectious and Infectious Diseases (NIAID).
Moderna’s mRNA-1273 is a new method of vaccination to protect against infectious diseases. Although RNA vaccine technology has been an improved messenger-developed RNA platform for decades, none was ever used for use in the U.S. prior to COVID-19.
At the interim analysis provided to FDA in EUA application, it was found that mRNA-1273 had 94.5% (95% CI, 86.5% –97.8%) efficacy against COVID-19 14 days after second dose in participants with no evidence of previous SARS-CoV-2 infection. In total, 11 cases of COVID-19 malignancy were observed, but all occurred in the placebo group.