Clinical Characteristics of Hospitalized COVID-19 Patients Who Received at Least One Dose of COVID-19 Vaccine.

Piotr Rzymski,Barbara Szczepańska,Monika Pazgan-Simon,Robert Flisiak,Tadeusz Łapiński,Iwona Mozer-Lisewska,Krzysztof Simon,Dorota Zarębska-Michaluk,Michał Chojnicki

doi:10.3390/vaccines9070781

Abstract

The clinical trials of the COVID-19 vaccines that are authorized in the European Union have revealed high efficacy in preventing symptomatic infections. However, during vaccination campaigns, some vaccine recipients, including those partially and fully vaccinated, will experience severe COVID-19, requiring hospitalization. This may particularly concern patients with a diminished immune response to the vaccine, as well as non-responders. This work has retrospectively analyzed the 92 cases of patients who were hospitalized between 27 December 2020 and 31 May 2021 in four Polish healthcare units due to COVID-19, and who have previously received the COVID-19 vaccine (54.3% ≤ 14 days after the first dose, 26.1% > 14 days after the first dose, 7.6% ≤ 14 days after the second dose, and 12% > 14 days after the second dose). These patients represented a minute fraction (1.2%) of all the COVID-19 patients who were hospitalized during the same period in the same healthcare institutions. No significant differences in white blood count, absolute lymphocyte count nadir, C-reactive protein, interleukin-6, procalcitonin, oxygen saturation, lung involvement, and fever frequency were found between the recipients of the first and second vaccine dose. A total of 15 deaths were noted (1.1% of all fatal COVID-19 cases in the considered period and healthcare units), including six in patients who received the second dose (five > 14 days after the second dose)—three of these subjects were using immunosuppressive medicines, and two were confirmed to be vaccine non-responders. The study reassures that severe COVID-19 and deaths are not common in vaccinated individuals, highlights that the clinical course in such patients may not reveal any distinctive features, and advocates for close monitoring of those at a higher risk of vaccine failure.

Highlights

The start of the rollout of COVID-19 vaccines at the turn of 2020–2021 brought new hope to the fight against the pandemic [1,2]
A total of 92 patients were considered in this analysis—they constituted 1.22% of all COVID-19 patients who were hospitalized during the same period (27 December 2020– 31 May 2021) in the considered healthcare units
None of the patients who were considered in the analysis underwent the documented SARS-CoV-2 infection prior to vaccination

Summary

Introduction

The start of the rollout of COVID-19 vaccines at the turn of 2020–2021 brought new hope to the fight against the pandemic [1,2]. The vaccines that are authorized in the European Union have been proven to have a good safety profile, be immunogenic, and provide a high efficacy against symptomatic SARS-CoV-2 infection [3,4,5,6]. Three out of four vaccines that are authorized in the European Union require two doses, separated by specific intervals outlined in the summary of product characteristics (SmPC): BNT162b2 (BioNTech/Pfizer) by 21 days, mRNA-1273 (Moderna) by 28 days, and AZD1222 (Oxford/AstraZeneca) by 4–12 weeks. According to the clinical data, the partial protection against symptomatic infection begins around two-to-three weeks after the first dose, when the anti-spike IgG antibodies emerge. Since the vaccine administration is conducted during the high spread of SARS-CoV-2 in the population, the risk of infections among vaccinated individuals, especially those who received only one dose, must be considered

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