While COVID-19 is relatively getting controlled, new mutations to the virus are posing a new threat and proving the necessity of getting the vaccine. Many concerns are rising surrounding the vaccines. They range from absurd claims of an incoming zombie apocalypse to genuine complaints regarding the vaccine’s safety and its side effects. This article explores the mechanism, efficacy, safety, and latest research surrounding the Russian vaccines, Sputnik V it’s one-dose version Sputnik light, that are currently being distributed in Syria.
Sputnik V
Sputnik V was the first vaccine to be approved for use in any country. A huge portion of the controversy surrounding the vaccine begun due to the early authorization by the Russian government which occurred before the clinical trials results were published.1 However, since then, there has been mounting evidence proving its safety and efficacy against symptomatic and severe COVID cases.
Mechanism
Sputnik V is made up of two recombinant adenovirus vectors that carry the gene for SARS-CoV-2 spike protein into the cell where it gets translated in order to initiate an immune response. This spike protein is able to entice humoral and cellular immune responses, which allows for the production of immunoglobulins. Memory T-cells are then able to retain that information and prepare for a future COVID-19 infection.
Unlike other two-dose vaccines, Sputnik consists of two different doses, the first contains rAd26 while the second contains rAd5. These adenoviruses have been genetically modified, inhibiting their ability to replicate and cause disease in the host. Each of these two adenoviruses introduce the gene in a slightly different method. This can theoretically boost efficacy and make it last longer.
Efficacy
According to a phase 3 clinical trial2 conducted on 21,977 adults in Russia, Sputnik V showed an efficacy of 91.6% when it comes to preventing Covid-19 infection. That means you’re 91.6% less likely to be infected after having the vaccine. Nevertheless, this efficacy rate was arrived at without taking into consideration the severity of the infection. When it comes to moderate and severe cases of COVID-19, the efficacy rate was 100%, which essentially means there were no confirmed moderate or severe cases in the vaccine group.
Notably, the efficacy against moderate or severe cases were 73.6% after the first shot, which initiated the idea of introducing Sputnik Light, an easily manufactured and stored dose of rAd26 alone. The one-dose Sputnik Light then showed 79.4% efficacy against symptomatic disease, according to a press-release from the Gamaleya Institute.3
Safety
Studies regarding Sputnik V have so far only included age-groups of 18 and older. As a result, no conclusions can be made regarding possible side-effects in younger age groups. The same can be said regarding pregnant and breastfeeding women. A recent media statement by the CDC asserts the safety of COVID-19 vaccines in pregnant, breastfeeding and 12-year or older people.4 However, this only applies to the authorized vaccines in the United States (PfizerBiontech, Moderna, and Johnson & Johnson). Moreover, Sputnik V authorization for emergency medical use by WHO and EMA remains pending.5 Though this is not to say that the Sputnik vaccine is not safe; in fact, the current evidence suggests otherwise.
Based on data from the phase 3 clinical trial2, the most common side-effects were:
- Flu-like illness
- Fatigue
- Headache
- Local reactions
Side-effects reported by recipents after receiving Sputnik Light included6, 2:
- Fever
- Headache
- Fatigue
- Muscle aches
- Mild pain at the injection site
It is important to note that in very rare cases, an allergic reaction to the vaccine may occur and vaccine recipients must be informed to prevent complications and get medical help immediately.
Some serious adverse events such as deep vein thrombosis, hypertension, renal colic, and acute sinusitis were reported among the vaccine group in the clinical trial2. However, none of these events were linked to the vaccine.
Unlike other adenovirus vector vaccines, Sputnik V has not yet shown rare blood clotting side-effects that were seen in the Oxford-AstraZeneca and Johnson & Johnson7. Some suggest that this may be due to the small sample size that is incapable of monitoring such an extremely rare adverse event. Nonetheless, Sputnik V is now approved in 70 countries8, and widely spread across the globe, yet with no such reports appearing thus far.
More research is underway
Many countries that have approved Sputnik V, such as UAE, India, Argentina, and Venezuela are currently running clinical trials that will help provide a clearer picture for the vaccine’s safety profile8. Furthermore, Astrazeneca has previously announced that it will be exploring the possibility of combining adenovirus vaccines with the Gamaleya institute’s Sputnik V9.
In conclusion, current scientific evidence provides growing evidence of the safety and efficacy of Sputnik V and Light in preventing moderate to severe cases of Covid-19 and hospitalizations. In response to the current public health crisis, it is ill-advised to choose not to take the vaccine especially when it’s benefits substantially outweigh the risks.
References
- Link 1
- Clinical Trial
- Sputnik light press release
- CDC Link
- WHO and EUA qualified vaccines
- Link 6
- Link 7
- COVID vaccine tracker
- AstraZeneca press release
Written by Zein Hanouneh
Zeintific 