Comparative efficacy and safety of the BioNTech Pfizer vaccine mRNA Covid-19 vaccine, a placebo-controlled trail in Mosul city
Author(s): Ghaith Rabie Mohammed* and Ghada Younis Abdulrahman
Abstract
Background: Tens of millions of individuals have been affected by a global pandemic of the coronavirus diseases 2019 (Covid-19) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We desperately needed vaccinations that are both safe and effective, as soon as possible. Methods : We randomly assigned individuals 16 years of age and older to receive one dose, two doses, or three doses 21 days apart in one arm taking the BNT162b2 vaccine candidate (30 g per dose) to be followed prospectively, and a second arm of placebo to be followed retrospectively in an ongoing multinational, placebo-controlled, observer-blinded, pivotal efficacy trial. The SARS-CoV-2 full length spike protein is encoded by the nucleoside-modified RNA vaccine BNT162b2, which is packaged as a lipid nanoparticle. The vaccine's effectiveness against the incidence of laboratory-confirmed Covid-19 infections and safety were the main end objectives. Results: 75 people in all underwent randomization, and of them, 40 got injections of BNT162b2 and 35 were retrospectively followed to be a placebo. Participants assigned to receive one dose of BNT162b2 experienced 5 cases of Covid-19 with onset at least 60 days up to 19 days later; participants assigned to receive two doses of BNT162b2 experienced one case; participants assigned to receive three doses of BNT162b2 experienced none; participants assigned to receive placebo experienced 21 cases. The extent of vaccination determines the degree of protection; individuals with three vaccination doses experienced 100% protection against reinfection within three days. Taking into account that the placebo group, separated into two subgroups-those who were hospitalized at the time of sampling and those who received their first dose of vaccination-had a 100% and 60% risk, respectively, of contracting an illness the first time and again. If we take into account the relative risk of having a second infection (RR=5.13 in favor of the placebo group), this translates to a five-fold increase in protection against reinfection compared to non-vaccinated individuals. Short-term, mild-to-moderate discomfort at the injection site, weariness, and headache were all part of BNT162b2's safety profile. The frequency of severe adverse events was minimal and comparable across the placebo and vaccination groups. Conclusions : A three-dose regimen of BNT162b2 offered 80.5% average protection against Covid-19 in people 16 years of age or older. Similar to previous viral vaccinations, safety was shown over a median of three months.