Disease severity and efficacy of homologous vaccination among patients infected with SARS‐CoV‐2 Delta or Omicron VOCs, compared to unvaccinated using main biomarkers

Abstract

From March 2021, various countries including Iraq issued prompted recommendations for increased COVID‐19 vaccine protection in individuals especially those at risk of catching the virus (i.e., lifestyle, health sector workers, and chronic diseases). It is critically important to understand the impact of COVID‐19 vaccinations with the most commonly used vaccines (Pfizer and AstraZeneca) among populations either on the severity of the disease or the transmissibility of SARS‐CoV‐2 variants of concern (VOCs) and in sequential waves. This study was conducted to establish the clinical severity of COVID‐19 caused by Delta and Omicron SARS‐CoV‐2 variants among patients who either attended or were admitted to hospitals and to compare the effectiveness of Pfizer and AstraZeneca COVID‐19 vaccines (single or double doses) at least to prevent hospitalizations if not eradicating the pandemic. A case–control study was done of 570 hospitalized patients; including 328 COVID‐19 confirmed patients (166 males, 160 females) who received homologous vaccinations and 242 unvaccinated patients (128 males, 114 females) during the studied waves. The study showed that unvaccinated COVID‐19 patients in both waves had expressed significantly a higher number and longer periods of symptoms than vaccinated ones. Additionally, there was no significant effect of vaccine types, Pfizer and AstraZeneca or vaccine shot numbers on the PCR‐Ct in the last (Omicron) wave of the pandemic. However, in the previous (Delta) wave of the pandemic, fully vaccinated (double doses) COVID‐19 patients had higher PCR‐Ct values. Whether among vaccinated or unvaccinated patients, lower CRP levels recorded during the Omicron wave than that of the Delta wave, and regardless of the vaccine type or shot numbers, there were no significant differences between the two waves. Lower WBCs were observed in patients (vaccinated and unvaccinated) infected with the Delta variant in comparison to those infected with the Omicron variant and without any remarkable effect of the vaccine type or shot numbers. This is the first molecular and investigational study of the Delta variant and circulated Omicron in Iraq, regarding the severity of these two waves of SARS‐CoV‐2 pandemic and the efficacy of homologous vaccination, indicating the insufficiency of two doses and the demand for booster dose(s) as the most effective way of keeping on the safe‐side against SARS‐CoV‐2.

SARS-CoV-2 Variants Show Different Host Cell Proteome Profiles With Delayed Immune Response Activation in Omicron-Infected Cells

“…Furthermore, Omicron BA.1 was shown to be less pathogenic in vivo when compared to other VOCs ( 11 , 12 , 13 ) and less severe Covid-19 cases were reported in areas in which Omicron BA.1 was the dominating variant ( 11 , 14 , 15 , 16 , 17 ). Recent studies have confirmed the lower pathogenicity of BA.1, but less severe courses of Covid-19 are also due to the higher vaccination rate in the BA.1 wave compared to the Delta wave ( 18 ).…”

Genetic polymorphism between the Sorani and Hawrami kurdish populations and COVID-19 outcome

“…Coronavirus Disease 2019 (COVID- 19) is a worldwide pandemic with a high mortality rate. It is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) [1,2]. Patients infected with SARS-CoV-2 exhibit a broad variety of symptoms and disease progressions that are not solely due to their age or other health issues.…”

Response to comments to the editor on “Disease severity and efficacy of homologous vaccination among patients infected with SARS‐CoV‐2 Delta or Omicron VOCs, compared to unvaccinated using main biomarkers”

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We appreciate the interest in our article entitled "Disease severity and efficacy of homologous vaccination among patients infected with SARS-CoV-2 Delta or Omicron VOCs, compared to unvaccinated, using main biomarkers". 1 The commentors' comments were helpful in correcting a handful of typos in the article. However, our response aims to improve their understanding and widen their knowledge on the article.Comment 1: First of all, the article claimed that this is a "first molecular study" of covid-19 variants in Iraq.

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