Efficacy and safety of an inactivated whole-virion vaccine against COVID-19, QazCovid-in®, in healthy adults: A multicentre, randomised, single-blind, placebo-controlled phase 3 clinical trial with a 6-month follow-up

Berik Khairullin; Kunsulu Zakarya; Mukhit Orynbayev; Yergali Abduraimov; Markhabat Kassenov; Gulbanu Sarsenbayeva; Kulyaisan Sultankulova; Olga Chervyakova; Balzhan Myrzakhmetova; Aziz Nakhanov; Ainur Nurpeisova; Kuandyk Zhugunissov; Nurika Assanzhanova; Sergazy Nurabayev; Aslan Kerimbayev; Zakir Yershebulov; Yerbol Burashev; Ilyas Kulmagambetov; Timur Davlyatshin; Maria Sergeeva; Zhanna Buzitskaya; Marina Stukova; Lespek Kutumbetov

doi:10.1016/j.eclinm.2022.101526

Efficacy and safety of an inactivated whole-virion vaccine against COVID-19, QazCovid-in®, in healthy adults: A multicentre, randomised, single-blind, placebo-controlled phase 3 clinical trial with a 6-month follow-up

EClinicalMedicine. 2022 Jun 25:50:101526. doi: 10.1016/j.eclinm.2022.101526. eCollection 2022 Aug.

Authors

Berik Khairullin¹, Kunsulu Zakarya¹, Mukhit Orynbayev¹, Yergali Abduraimov¹, Markhabat Kassenov¹, Gulbanu Sarsenbayeva¹, Kulyaisan Sultankulova¹, Olga Chervyakova¹, Balzhan Myrzakhmetova¹, Aziz Nakhanov¹, Ainur Nurpeisova¹, Kuandyk Zhugunissov¹, Nurika Assanzhanova¹, Sergazy Nurabayev¹, Aslan Kerimbayev¹, Zakir Yershebulov¹, Yerbol Burashev¹, Ilyas Kulmagambetov², Timur Davlyatshin³, Maria Sergeeva⁴, Zhanna Buzitskaya⁴, Marina Stukova⁴, Lespek Kutumbetov¹

Affiliations

¹ Research Institute of Biological Safety Problems of the Science Committee of the Ministry of Education and Science of the Republic of Kazakhstan, Gvardeysk, Kazakhstan.
² Centre for Clinical Medicine and Research, Almaty, Kazakhstan.
³ Clinical diagnostic laboratory "Omikron 3D", Almaty, Kazakhstan.
⁴ Smorodintsev Research Institute of Influenza, Saint Petersburg, Russia.

Abstract

Background: Vaccination remains the primary measure to prevent the spread of the SARS-CoV-2 virus, further necessitating the use of effective licensed vaccines.

Methods: From Dec 25, 2020, to July 11, 2021, we conducted a multicenter, randomised, single-blind, placebo-controlled phase 3 efficacy trial of the QazCovid-in® vaccine with a 180-day follow-up period in three clinical centres in Kazakhstan. A total of 3000 eligible participants aged 18 years or older were randomly assigned (4:1) to receive two doses of the vaccine (5 μg each, 21 days apart) or placebo administered intramuscularly. QazCovid-in® is a whole-virion formaldehyde-inactivated anti-COVID-19 vaccine, adjuvanted with aluminium hydroxide. The primary endpoint was the incidence of symptomatic cases of the SARS-CoV-2 infection confirmed by RT-PCR starting from day 14 after the first immunisation. The trial was registered with ClinicalTrials.gov NCT04691908.

Findings: The QazCovid-in® vaccine was safe over the 6-month monitoring period after two intramuscular immunisations inducing only local short-lived adverse events. The concomitant diseases of participants did not affect the vaccine safety. Out of 2400 vaccinated participants, 31 were diagnosed with COVID-19; 43 COVID-19 cases were recorded in 600 placebo participants with onset of 14 days after the first dose within the 180-day observation period. Only one severe COVID-19 case was identified in a vaccine recipient with a comorbid chronic heart failure. The protective efficacy of the QazCovid-in® vaccine reached 82·0% (95% CI 71.1-88.5) within the 180-day observation period.

Interpretation: Two immunisations with the inactivated QazCovid-in® vaccine achieved 82·0% (95% CI 71.1-88.5) protective efficacy against COVID-19 within a 180-day follow-up period.

Funding: The work was funded by the Science Committee of the Ministry of Education and Science of Kazakhstan within the framework of the Scientific and Technical Program "Development of a vaccine against coronavirus infection COVID-19". State registration number 0.0927.

Keywords: COVID-19; Clinical trial; Efficacy; Phase 3; Vaccine; Virus.

Associated data

ClinicalTrials.gov/NCT04691908