Russia's COVID-19 vaccine shows immune response; larger trials to follow

Russia’s COVID-19 vaccine candidate codenamed Sputnik-V has been successful at inducing an immune response against the new coronavirus infection, according to the results of the study published in the scientific journal Lancet.

Russia, which has been severely affected by the COVID-19 pandemic in recent months, became the first country to approve a vaccine against the respiratory infection caused by the SARS-CoV-2 virus on 11 August, and has been derived from two adenovirus vectors, which are the common viruses behind the common cold infection among people.

According to the report published on 4 September, every participant in two small trials conducted over the months of June and July indicated that they had developed antibodies against the coronavirus without any serious side effects.

Sputnik-V vaccines were tried with two formulations on 76 people during non-randomized trials in the initial phase, which were found to be safe during the 42-day observation. These doses have been claimed to produce antibody response in the body of the participants within 21 days. The researchers have also claimed to have seen T cell responses in participants under the influence of the vaccine, which is important for having long-term immunity against the viral infection.

However, it must be emphasised that the number of participants that the trial recruited is not enough to prove the vaccine to be completely safe and competent. A vaccine formulated against a disease is considered to be truly competent and safe when it is tried on thousands of participants as part of the final trial. Russia recently announced that it would include as many as 40,000 people in its next phases of the trial to test the effectiveness of the vaccine.

Both vaccine formulations found to be safe

Both vaccine formulations found to be safe

The Lancet made these claims based on the results of two small-level human trials that lasted 42 days. One of these trials used a frozen formulation of the vaccine, while a lyophilisation (freeze dried) based formulation was used in the second trial.

The frozen formulation was tried with a large-scale vaccine in mind, and the freeze-dried formula was created keeping in mind areas where it is inaccessible to reach and the vaccine may need to be stored at a temperature of two to eight degrees Celsius for a longer duration.

The study explains that the vaccine has been developed in such a way that it spreads in the body towards the spike protein of SARS-COV-2. According to the researchers, it can cause a common cold, but the virus cannot make copies in human cells. In such a situation, the body is not vulnerable to any disease and generates immunity against the new coronavirus infection.

The trials were conducted in two hospitals in Russia, and both tests were open-label and non-randomized, meaning that the participants knew they were going to be vaccinated. The age of these participants ranged between 18 and 60 years and they were perfectly healthy.

The group stayed in the hospital for 28 days after the vaccine was administered to them. In each trial under the first phase, the component of both types of vaccines was given to these participants. Four groups of nine participants were given a frozen and freeze-dried formula based vaccine.

The participants were given full doses of both vaccines in the second phase, while the main vaccination was performed on the first day. The booster vaccine that follows the main dose was given on the 21st day of the trial.

To differentiate between immunity and natural immunity from the vaccine, the researchers sought the help of 4,817 normal and moderate patients' convalescent plasma, after being cured from COVID-19.

The investigations revealed that both vaccine formulations are safe and have no serious side effects. According to the researchers, during the trial, there are common side effects such as pain at the site of the injection, hyperthermia, headache, asthenia (weakness or lack of energy), body pain and joint pain that can be experienced. The report added that these side effects have also appeared in other vaccines.

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