Sputnik V peer reviewed

Sputnik V (Gam-Covid-Vac)

2 doses, 3 weeks apart

Muscle injection

Freezer storage

Developing an alternative formulation that can be refrigerated

Gamaleya Research Institute (Ministry of Health)

Combination of two adenoviruses called Ad5 and Ad26

August 11th President Putin announced approval

Before phase 3 trials had started

November, Russian government began offering Sputnik V within Russia

Widespread hesitancy

Phase 3, Russia, Belarus, UAE, Venezuela, India

Gamaleya Institute joined forces in December with the AstraZeneca

AstraZeneca / Gamaleya combination started Phase 1 trial on Dec. 24

Safety and efficacy of an rAd26 and rAd5 vector-based heterologous prime-boost COVID-19 vaccine: an interim analysis of a randomised controlled phase 3 trial in Russia

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Background

A heterologous recombinant adenovirus

Phase 2 results,

showed a good safety profile and induced strong humoral and cellular immune responses

Interim analysis of this phase 3 trial

Methods

Randomised, double-blind, placebo-controlled, phase 3 trial

25 hospitals and polyclinics in Moscow

Participants at least 18 years, with negative PCR and IgG and IgM tests

Randomly assigned (3:1) to receive vaccine or placebo

Two shots, 21 days apart

First dose, rAd26

Second dose, rAd5),

Both vectors carrying the gene for the full-length SARS-CoV-2 glycoprotein S

Outcome recorded 21 days after second shot (vaccine or placebo)

Finding

Sept 7 to Nov 24, 2020

N = 21 977

Randomly assigned

Vaccine group, n = 16 501

Placebo group, n = 5476

N = 19 866 received two doses of vaccine or placebo and were included

(2,144 participants older than 60 years, 1,611 in the vaccine group and 533 in the placebo group)

Primary outcome analysis

Included all participants who had received at least two doses at the time of database lock

Vaccine group, n = 14,964

16 (0·1%) confirmed COVID infections

No cases of moderate or severe COVID-19 confirmed at least 21 days after dose 1

Placebo group, n = 4,902

62 (1·3%) confirmed COVID infections

20 cases of moderate or severe COVID-19 confirmed at least 21 days after dose 1

Efficacy

91·6%

Vaccine efficacy was 91·8 in participants older than 60 years

Interim immunogenicity

Vaccine group

RBD-specific IgG detected in 336 (98%) of 342 samples

Seroconversion rate of 98·25%

Higher levels of interferon-gamma

(secreted by activated T helper lymphocytes, T cytotoxic lymphocytes, B lymphocytes and NKs)

Significantly higher levels of IFN-γ secretion upon antigen restimulation

Placebo group

RBD-specific IgG was detected in 17 (15%) of 114 samples

Seroconversion rate of 14·91%

(p less than 0·0001 vs the vaccine group)

Adverse events

Grade 1

7485 [94·0%] of 7966 total events

Serous adverse events

Vaccine group

45 (0·3%) of 16, 427

Placebo group

23 (0·4%) of 5435

None were considered associated with vaccination

Four deaths were reported during the study

Vaccine group

Three (less than 0·1%) of 16 427

Placebo group

One (less than 0·1%) of 5435

None of which were considered related to the vaccine

Interpretation

This interim analysis of the phase 3 trial of Gam-COVID-Vac showed 91·6% efficacy against COVID-19 and was well tolerated in a large cohort