Cleveland Clinic Survey Results

Scientists at the Cleveland Clinic in the United States recently evaluated the efficacy of the Coronavirus Disease 2019 COVID-19) vaccine with or without a history of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. did.

The findings reveal that people previously infected with SARS-CoV-2 do not benefit from vaccination, and the COVID-19 vaccine should be prioritized over those who have not been previously infected. This study currently shows that medRxiv* Preprint server.

Background

In the United States, the US Food and Drug Administration (FDA) has approved two mRNA-based COVID-19 vaccines developed by Pfizer / Bio NTech and Moderna. efficacy For SARS-CoV-2 infection and COVID-19 disease in clinical trials. However, the ability to vaccinate most of the world’s population is limited by the supply of vaccines.

The Global Access (COVAX) initiative for the COVID-19 vaccine has been launched to ensure fair access to vaccines worldwide. Vaccines are in serious shortage in many countries, especially those with low socioeconomic status. Therefore, in order to maximize the benefits of vaccines, the most vulnerable people should be given priority in vaccination.

Currently, most countries prioritize vaccination of medical and other front-line workers, the elderly and people with comorbidities.

To further narrow down the prioritization criteria, scientists in the current study evaluated the need for a COVID-19 vaccine for individuals previously infected with SARS-CoV-2.

Analyze “previously infected” as a time-independent covariate and treat “vaccinated” as a time-dependent covariate.

Study design

The survey was conducted on 52,238 employees at the Cleveland Clinic. A positive RT-PCR test was considered to define SARS-CoV-2 infection. Participants received two Pfizer / BioNTech or Moderna COVID-19 vaccines at 28-day intervals. Participants were considered vaccinated 14 days after receiving the two vaccines.^And Vaccine dose. Similarly, participants who tested positive for SARS-CoV-2 at least 42 days before the start of vaccination were considered previously infected.

Important observations

Of all enrolled participants, 5% were previously infected with SARS-CoV-2. Only 47% of previously infected participants were vaccinated by the end of the study, compared to 59% of uninfected participants. Approximately 63% of vaccinated participants received the Moderna vaccine.

Analysis of cumulative incidence of COVID-19 reveals that SARS-CoV-2 infection occurred almost exclusively in previously uninfected and unvaccinated participants during the course of the study. became.

Interestingly, previously infected and currently unvaccinated participants, previously infected and currently vaccinated participants, previously uninfected and currently vaccinated participants There was no significant difference in the incidence of COVID-19 among the participants.

Participants in these three groups had a significantly lower incidence of SARS-CoV-2 infection than those who were previously uninfected or who are not currently vaccinated.

Specifically, of all infections during the study period, 99.3% occurred in participants who were previously uninfected and remained unvaccinated. In contrast, only 0.7% of participants who were previously uninfected but are currently vaccinated had an infection.

Importantly, no incidence of SARS-CoV-2 infection was observed in previously infected participants, with or without vaccination.

A Simon-Makuch plot showing the cumulative incidence of COVID-19 in subjects who were previously infected with COVID-19 and who were not previously infected with COVID-19, and who were vaccinated and unvaccinated. The unvaccinated curve is based on data from those who did not receive the vaccine during the study period and those who were waiting to be vaccinated. Zero Day was December 16, 2020, the day vaccination began at our facility. Error bars represent 95% confidence intervals. Seven subjects who were early vaccinated as participants in the clinical trial were considered vaccinated during the study period. Twelve subjects who were first vaccinated in the first week of the vaccination campaign managed to get the second vaccination three weeks later and were vaccinated earlier than 42 days after the start of the vaccination campaign. Was considered.

Further statistical analysis observed that COVID-19 vaccination significantly reduced the risk of SARS-CoV-2 infection in previously infected participants, but not in previously infected participants. ..

Although this study does not directly estimate the duration of protection from natural infections, previously infected participants are protected from COVID-19 for at least 10 months after the onset of symptoms or a positive test result. It was observed to remain.

Significance of research

The findings show that individuals with previously symptomatic COVID-19 are less likely to benefit from vaccination.

In contrast, individuals who have not previously been infected with SARS-CoV-2 can benefit most from vaccination. Therefore, based on research results, the COVID-19 vaccine should be prioritized for inexperienced individuals with no history of SARS-CoV-2 infection.

*Important Notices

medRxiv Is published as a preliminary scientific report that has not been peer-reviewed and is therefore considered definitive, guides clinical practice / health-related behaviors, and is treated as established information. It’s not a thing.