COVID-19 Roundup: Safety Investigation of Vaccines in Older Adults, Fluvoxamine Does Not Improve Symptoms, the Use of Convalescent Plasma in Immunocompromised Patients With COVID-19, and more

Jessica Ganga

CDC, FDA Investigating Possible Ischemic Stroke in Older Adults After Vaccination1

The CDC’s Vaccine Safety Datalink (VSD)—a vaccine safety monitoring system—prompted an additional investigation into the safety of the bivalent Pfizer-BioNTech COVID-19 vaccine in people aged 65 years and older, raising the question of individuals experiencing ischemic stroke.

After the updated (bivalent) COVID-19 vaccines became available, the VSD met the criteria necessary to further investigate the likelihood of people having an ischemic stroke in the 21 days following vaccination compared with days 22 to 42 following vaccination. The safety signal has not been established with the bivalent Moderna vaccine.

According to the news release, no other safety systems have shown a similar signal and multiple analyses have not validated the VSD signal. Further, the CDC and FDA note that the complete data suggests that it is “very unlikely” the VSD signal represents a “true clinical risk.”

“CDC continues to recommend that everyone ages 6 months of age and older stay up-to-date with COVID-19 vaccination; this includes individuals who are currently eligible to receive an updated (bivalent) vaccine,” the CDC writes.

Fluvoxamine Shown to Not Improve COVID-19 Symptoms in Patients2

The use of fluvoxamine in outpatients with COVID-19 does not shorten symptom duration, according to a recent study.

Researchers examined the efficacy of a 50 mg dose of fluvoxamine on patients with mild to moderate symptoms of COVID-19. Participants included in the study (n = 1288) were randomized to receive either 50 mg of fluvoxamine twice daily (n = 674) for 10 days or placebo (n = 614).

In the fluvoxamine group, the median time to sustained recovery (the third day of three consecutive days without symptoms) was 12 days compared with a median time of 13 days in the placebo group. Further, in the fluvoxamine group, 26 participants were hospitalized, had an urgent care visit, an emergency department visit, or died.

“These findings do not support the use of fluvoxamine at this dose and duration in patients with mild to moderate COVID-19,” the researchers concluded.

The study included several limitations. Few clinical events occurred, which was due to the broadly inclusive population and resulted in an inability to study the efficacy of clinical outcomes such as hospitalization.

COVID-19 Convalescent Plasma Decreases Mortality in Immunocompromised Patients3

Patients who are immunocompromised and have COVID-19 benefit from the transfusion of COVID-19 convalescent plasma, according to a recent study.

Researchers conducted a systematic review of clinical studies that involved immunocompromised patients with COVID-19 who were treated with specific neutralizing antibodies via COVID-19 convalescent plasma transfusion. The review and meta-analysis included three randomized clinical trials, five controlled studies, 125 case series, and 13 uncontrolled large case series.

Upon analysis, the researchers found that a decrease in mortality among patients was associated with treatment using COVID-19 convalescent plasma transfusion.

The study included limitations such as the lack of access to patient-level data for many of the studies that were used in the analysis.

“Although these summary findings are encouraging for the use of therapeutic convalescent plasma in COVID-19 patients with primary or secondary immunosuppression, there remains a paucity of well-controlled, published data in these important patient populations. The clinical use of COVID-19 convalescent plasma and Vax-Plasma in patients who are immunocompromised and have COVID-19 may warrant further investigation” the researchers concluded.

Low Mortality Rate Among Patients With Myocarditis Post-COVID-19 mRNA Vaccination4

According to a recent study, a lower mortality rate was found among patients with myocarditis who received a mRNA COVID-19 vaccine compared with those with viral infection-related myocarditis.

The researchers compared patients hospitalized with myocarditis within 28 days of receiving the Pfizer-BioNTech vaccination with patients diagnosed with infection-related myocarditis before the pandemic (2000-2019)

The study included 866 patients for analysis. Over the 180-day follow-up period, one death occurred out of 104 patients with postvaccination myocarditis. Among the 762 patients with viral infection-related myocarditis, 84 deaths occurred. Additionally, one case of dilated cardiomyopathy and two cases of heart failure were noted in the postvaccination group, compared with 28 and 93 patients in the viral infection-related group, respectively.

“This study found a significantly lower rate of mortality among individuals with myocarditis after mRNA vaccination compared with those with viral infection–related myocarditis,” the researchers concluded. “Prognosis of this iatrogenic condition may be less severe than naturally acquired viral infection–related myocarditis.”



  1. CDC & FDA identify preliminary COVID-19 vaccine safety signal for persons aged 65 years and older. News release. Center for Disease Control and Prevention; January 13, 2023. Accessed January 30, 2023.
  2. McMarthy MW, Naggie S, Boulware DR, et al. Effect of fluvoxamine vs placebo on time to sustained recovery in outpatients with mild to moderate COVID-19. JAMA. Published online January 12, 2023. doi:10.1001/jama.2022.24100
  3. Senefeld JW, Franchini M, Mengoli C, et al. COVID-19 convalescent plasma for the treatment of immunocompromised patients: a systematic review and meta-analysis. JAMA Netw Open. Published online January 12, 2023. doi:10.1001/jamanetworkopen.2022.50647
  4. Lai FTT, Chan EWW, Huang L, et al. Prognosis of myocarditis developing after mRNA COVID-19 vaccination compared with viral myocarditis. J Am Coll Cardiol. 2022;80(24):2255-2265. doi:10.1016/j.jacc.2022.09.049