Kanikah Mehndiratta, MSc, University of Glasgow
Amongst so many vaccine options recently developed in different parts of the world, Sputnik V has proven to be a great candidate due to a lot of factors. Firstly, is its high efficacy of about 92% against the coronavirus disease caused by the SARS-CoV2 viral strains. Also known as the Gam-COVID-Vac, it has also reported the least number of side effects in most populations. Developed by the Gamaleya National Centre of Epidemiology and Microbiology, Russia, it got approval for use in August 2020 even before its phase III trials were conducted on a large population. Can a single dose of Sputnik V by itself provide a similar efficacy but vaccinates whole populations at a faster rate? If yes, this could bring quite a difference to the current global crisis related to vaccine shortage and its uneven distribution.
Single vaccine shot approach:
A study conducted by the Gamarnik Lab in Argentina on 289 healthcare workers made a comparison between single-dose and double dose efficacy of the Sputnik V. Published in the Cell Reports Medicine journal, all the participants that hadn’t reported a COVID-19 infection in the past, developed an effective immune response by generating IgG antibodies specific to the viral strain. Surprisingly, about 94% of them had developed the antibodies with the first dose injection itself. 90% even depicted neutralizing antibodies that interfere with the pathophysiology behind the infection.
Also, people who had got infected at least once reported higher levels even after a single dose in comparison to the fully vaccinated ones that had never contracted the COVID-19 infection. There was reported evidence of T-cell responses that would last longer too. The Gam-COVID-Vac consists of a heterologous recombinant virus of the adenovirus vectors such as the Ad26 and the Ad5 to express the SARS-CoV2 spike protein. Initially, 2 serotypes were being given at a gap of 21 days, keeping in mind any pre-existing immunity against the same virus and giving the effect a prime-boost. The virus itself is unarmed so that it cannot cause infection but only generate an immune response towards the spike protein it carries after modification. This spike protein from the SARS-Cov2 is helping in developing immunity against the infection. Other vaccine candidates are also showing good efficacy with a single dose application.
Significance of the study:
Thus, one can conclude that immunity against the SARS-CoV2 naturally acquired by the body can be effectively enhanced by one dose of the Sputnik V. But more research is needed into the duration of immune response and the levels of antibodies generated against the virus. Also, the large dose amount poses a challenge that can be addressed through further studies. The only fatalities reported in different studies have been in participants with major comorbidities and are being concluded as unrelated to the vaccine use. The vaccine has proven effective for all age groups by decreasing the severity of the disease in an infected individual which makes it a suitable candidate for use in the current scenario.
Also read: Closteroviridae: An exceptional virus family in wild citrus plants
References:
1. Rossi, A., Ojeda, D. S., Varese, A., Sanchez, L. N., Gonzalez Lopez Ledesma, M. M., Oviedo Rouco, S., Pallares, H. M., Costa Navarro, G., & Gamarnik, A. (2021). Sputnik v vaccine elicits seroconversion and neutralizing capacity to sars cov-2 after a single dose—Dataset. 1. https://doi.org/10.17632/5bjwph8xkr.1
2. van Tulleken C. (2021). Covid-19: Sputnik vaccine rockets, thanks to Lancet boost. BMJ (Clinical research ed.), 373, n1108. https://doi.org/10.1136/bmj.n1108
Author info:
Kanikah Mehndiratta is an avid researcher in the field of Genetics with a background in Biotechnology. She is a postgraduate from the University of Glasgow in their Medical Genetics and Genomics program. Currently, based in Chandigarh as a scientific writer, she involves herself mainly in projects related to neurological disorders. Outside of academics, she likes to read novels, travel and is involved in volunteer work mostly.
LinkedIn profile– https://www.linkedin.com/in/kanikah-mehndiratta-301830171
Other publications:
2. https://bioxone.in/news/worldnews/iga-virus-immune-complex-neutrophils-trap-for-sars-cov-2/
3. https://bioxone.in/news/worldnews/understanding-cancer-pathophysiology-via-isotopic-tracing/
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