Sputnik V COVID-19 vaccine
Sputnik V or Gam-COVID-Vac is an adenovirus viral vector vaccine for COVID-19 developed by the Gamaleya Research Institute of Epidemiology and Microbiology in Russia. It is the world's first registered combination vector vaccine for the prevention of COVID-19, having been registered on 11 August 2020 by the Russian Ministry of Health.
Gam-COVID-Vac was initially approved for distribution in Russia and then in 59 other countries on the preliminary results of Phase I–II studies eventually published on 4 September 2020. Approval in early August of Gam-COVID-Vac was met with criticism in mass media and discussions in the scientific community as to whether approval was justified in the absence of robust scientific research confirming safety and efficacy. A large-scale Brazilian study from Dec. 2020 to May 2021 confirmed its effectiveness and safety, as of Oxford–AstraZeneca's, i.e. above Sinopharm BIBP's.
Emergency mass-distribution of the vaccine began in December 2020 in countries including Russia, Argentina, Belarus, Hungary, Serbia, Pakistan, the Philippines, and the United Arab Emirates. The Sputnik V is currently registered and certified in 71 countries. However, as of April 2022 less than 2.5% of the people vaccinated worldwide have taken a Sputnik V dose. In early 2022, as a result of the 2022 Russian invasion of Ukraine, the United States and other countries placed the Russian Direct Investment Fund on the list of sanctioned Russian entities and people, significantly reducing Sputnik V's future commercial prospects.
The Gam-COVID-Vac vaccine itself is available in two forms: frozen and liquid. In addition to the main vaccine, vaccines and its derivatives were registered: Gam-COVID-Vac-Lyo, Sputnik Light, Gam-COVID-Vac-M.
Medical uses
The vaccine can be formulated in two ways: as a ready-to-use solution in water that is frozen at the common home-freezer storage temperature of or lower, and as a freeze-dried powder, "Gam-COVID-Vac-Lyo", which can be stored at. The freeze-dried powder must be reconstituted with sterile water before use. The lyophilized formulation of Gam-COVID-Vac is similar to the smallpox vaccine, circumventing the need for continuous "colder chain" or cold-chain storage – as required for the Pfizer–BioNTech and Moderna vaccines – and allowing transportation to remote locations with reduced risk of vaccine spoilage.The first dose is administered on the first day, and the second dose is administered on the 21st day to boost immune response. Both doses are administered into the deltoid muscle.
Sputnik Light is a registered single-dose vaccine consisting of only the first dose of Sputnik V. It is intended for areas with acute outbreaks and it will be used as a third dose for those who have received Sputnik V at least 6 months earlier. It can be stored at a normal refrigerator temperature of. The institute says this version would be ideally suited for areas with acute outbreaks, allowing more people to be vaccinated quickly.
Although Sputnik Light was not authorized by Ukraine or international organizations, tens of thousands of doses were shipped by Russia for use in non-government controlled parts of the eastern Donbas region from January 2021. Ukrainian officials criticized the move.
In January 2021, Sputnik Light commenced phase I/II trials. In February, Sputnik Light commenced phase III trials. Effectiveness is generally expected to slowly decrease over time.
A real-world study with participants aged 60–79 years in Argentina found that the single-injection vaccine is effective in preventing infections, effective against hospitalization, and against death. A phase III clinical trial in Russia also found an efficacy of 79%. According to Nextstrain, lineage B.1.1.317 was the dominant variant in Russia during the study period, while in Argentina lineage N.5 dominated at first, but soon many lineages coexisted in similar proportions.
Preliminary data from a study in Moscow in July 2021 indicate that the vaccine is effective against symptomatic disease from the Delta variant for three months after vaccination. In August 2021, RDIF announced that preliminary results from a study on heterologous prime-boost vaccination indicate that it is safe to administer Sputnik Light as the first dose, then the Oxford–AstraZeneca, Moderna or Sinopharm BIBP vaccine as the second dose, as well as the homologous course consisting of Sputnik Light as the second dose.
On 11 August 2021, the developers of the Sputnik V vaccine offered its 'Sputnik Light' vaccine to Pfizer for trial against the Delta variant.
Effectiveness
The effectiveness of COVID-19 vaccines, or any other vaccine, is determined in a mass vaccination in a "real-world" setting. This is an assessment of how well the vaccine protects people from outcomes such as infection, symptomatic illness, hospitalization, and death. Effectiveness is evaluated outside of clinical trials, which by contrast, evaluate the efficacy of the vaccine. A vaccine is generally considered effective if the estimate is ≥50% with a >30% lower limit of the 95% confidence interval. Effectiveness is generally expected to slowly decrease over time.On 25 August, a preliminary version of a case-control study indicated an unadjusted effectiveness of about 50% against symptomatic disease. The authors expected that adjusting for age and sex would increase the estimate, citing an increase from 66% to 81% when adjusting the data for effectiveness against hospitalization.
A large-scale study in Buenos Aires from 29 December 2020, to 15 May 2021, with 663,602 participants aged 60 and older who received Spunik V, the Oxford–AstraZeneca vaccine, or the Sinopharm BIBP vaccine observed an overall efficacy of against COVID-19-related deaths. The study noted that the three vaccines showed a similar effectiveness against death, and that the effectiveness against infection was similar to that of the Oxford-Astrazeneca vaccine and greater than that of the Sinopharm BIBP vaccine.
| Doses | Severity of illness | Delta | Alpha |
| 1 | Symptomatic | ||
| 1 | Hospitalization | ||
| 2 | Asymptomatic | ||
| 2 | Symptomatic | ||
| 2 | Hospitalization | ||
| 2 | Death |
A large-scale study was conducted in Mexico. The study compared 793,487 adults vaccinated with different vaccines with 4,792,338 unvaccinated adults between 24 December 2020, and 27 September 2021.The results were as follows:
| Vaccine | Incidental infection effectiveness | Hospitalization effectiveness | Mortality effectiveness |
| Spikevax | 91.45% | 78% | 93.46% |
| Comirnaty | 80.34% | 84.26% | 89.83% |
| Sputnik V | 78.75% | 81.38% | 87.7% |
| Covishield | 80.79% | 80.23% | 86.81% |
| Janssen | 82.18% | 77.33% | 85.79% |
| CoronaVac | 71.93% | 73.76% | 80.38% |
| Convidecia | 70.5% | 72.31% | 79.93% |
Efficacy
The vaccine efficacy of a COVID-19 vaccine or any other vaccine is evaluated in controlled clinical trials. It is an estimate of how many people who received the vaccine got the disease compared to how many people who got a placebo had the same outcome. On 2 February 2021, an interim analysis from the Moscow trial was published in The Lancet reporting an efficacy of after the second dose for all age groups, with no unusual side effects. For the age group of 60 years and older, the reported efficacy was 91.8%. On 12 May, a group of biostatisticians from Russia, the US, France, Italy and the Netherlands questioned the efficacy results in a correspondence in The Lancet, highlightingdata discrepancies,
substandard reporting,
apparent errors and numerical inconsistenciesand a very unlikely homogeneity in vaccine efficacy across age groups.
The authors responded by saying that they had provided the regulatory authorities with all the data necessary for obtaining approval, and that the data included with the paper were enough for readers to confirm the reported vaccine efficacy. They also addressed the protocol queries, and said numerical inconsistencies were "simple typing errors that were formally corrected".
In June 2022 a group of biostatisticians from Australia and Singapore published a paper suggesting that the almost identical efficacy for every age group from the Lancet paper is very unlikely to occur in genuine experimental data. The group called for a thorough investigation of the Lancet article, as well as the immediate release of anonymized individual patient data to an unbiased statistical expert, and suggested the article should be retracted. The Lancet Group recognized the concerns about the validity of data published in the article and invited the authors of the article to respond to these latest questions.
Adverse effects
Side effects are mostly mild and similar to other adenovirus vector vaccines such as the Oxford-AstraZeneca and the Janssen vaccines. However, unlike the Oxford-AstraZeneca and Janssen vaccines evidence does not suggest a risk of vaccine-induced immune thrombotic thrombocytopenia. However, a report from Argentina published in the New England Journal of Medicine described fatal vaccine-induced thrombocytopenia and thrombosis in a young woman after receipt of Sputnik-V.Pharmacology
Gam-COVID-Vac is a viral vector vaccine based on two recombinant replication-defective human adenoviruses: Ad26 and Ad5 replicated in HEK 293 cells. The viruses contain the gene that encodes the full-length spike protein of SARS-CoV-2 to stimulate an immune response. Adenoviral vectors for expression of the SARS-CoV-2 spike protein have also been used in two other COVID-19 vaccines. One is the Janssen COVID-19 vaccine, which utilizes the Ad26COV2 viral vector based on the human virus Ad26. For this vaccine, the cell line PER.C6 is used to replicate the vector. Another one, the Oxford–AstraZeneca COVID‑19 vaccine, uses chimpanzee adenovirus as the vector. For both the Oxford-AstraZeneca COVID-19 and Gam-COVID-Vac vaccines the producer cells for the production of non-replicating adenoviral vectors were obtained from the HEK 293 cell line. Each dose of Gam-COVID-Vac contains × 10 virus particles.Both Ad26 and Ad5 were modified to remove the E1 gene to prevent replication outside the HEK 293 cells. For the production of the vaccine, to propagate adenoviral vectors in which the E1 gene was deleted, HEK 293 cells are used, which express several adenoviral genes, including E1. However, although rare, homologous recombination between the inserted cellular sequence and the vector sequence can restore the replication capacity to the vector, with less than 100 replicating adenovirus particles per dose of the vaccine.