Comment on Jing Sun et al, Study comparing outcomes for partial vs full COVID-19 vaccination
Repost of comment published in JAMA Internal Medicine
Also, followup article in TrialSite News: “Major unreported protocol deviation in N3C COVID-19 vaccine trial”
Yim comment:
The study looked at the effect of SARS-CoV-2 vaccine on patient outcomes in the National COVID Cohort Collaborative (N3C). The database provided COVID-19 diagnoses for all patients and the corresponding vaccination status at COVID-19 diagnosis. With these data, the efficacy of partial vaccination was compared to the efficacy of full vaccination. Full vaccination provided a 28% risk reduction in comparison with partial vaccination. A comparison was also made between the prevalence of hospitalization with severe disease between the full vaccination and pre vaccination (unvaccinated) groups. The rate of severe disease in the full vaccination group was 16%, as compared to 24% in the pre vaccination group.
Why not also compare the prevalence of COVID-19 in the pre vaccination and full vaccination groups? Such a comparison would provide an independent estimate of vaccine efficacy.
Jin Sun comment:
Thank you for your comment and interest in our research. In an ongoing study, we are evaluating the vaccine efficacy in N3C. The current study was completed and submitted before all components evaluating vaccine efficacy were available.
Follow-up comment (submitted for publication but rejected):
Your answer is not very forthcoming. The omission of the vaccine efficacy result is very concerning.
Yim email to Sun:
I commented on your recent article in JAMA Internal Medicine. Do you intend to publish the results of the study on vaccine efficacy?
Sun email response:
Thanks for your comments. Yes, the study is ongoing and we do plan to publish it
Yim email response:
You say that the study is ‘ongoing’, yet the study data collection period was December 10, 2020 to October 14, 2021. What exactly is it about the study that is ongoing?
Sun did not respond