Possible Russian COVID-19 vaccine is safe, according to The Lancet

The COVID-19 vaccine candidate being developed by Russian scientists has caused no adverse incidents and generates antibodies, according to preliminary results from clinical trials, detailed in a study released Friday by the British medical journal "The Lancet".

The report comes weeks after Russia announced that it had a vaccine against covid-19, called Sputnik V, but without providing details of the clinical trials, which caused concern in the scientific world.

The study details the first findings of two early-stage clinical trials involving 76 people.

The expert group found that two formulations - one frozen and one freeze-dried - of a two-part vaccine are "safe" as they did not identify serious adverse reactions for more than 42 days and induced antibody responses in all participants within 21 days.

The secondary results of the trials (not as relevant as the primary results) also led to the conclusion that the vaccines also produce, within 28 days, T-cell responses, which detect and kill invading pathogens or infected cells.

The frozen formulation is designed for large-scale use, while the freeze-dried formulation is developed with hard-to-reach regions in mind, as it can be stored at temperatures between 2 and 8 degrees Celsius.

The study explains that the vaccine includes two adenovirus vectors-the so-called "recombinant human adenovirus type 26" or rAd26-S and the "recombinant human adenovirus type 5" or rAd5-S-modified to express the SARS-CoV-2 "peak protein", a key tool the virus uses to invade human cells.

In the tests, the adenoviruses were weakened so that they cannot replicate in human cells and cannot cause disease (as they usually cause the common cold).

Such adenovirus vectors have already been safely used in many clinical trials, according to the study, which suggests that these vaccines aim to stimulate both arms of the immune system: antibodies and T-cell responses, so that they attack the virus when it circulates in the body and also the cells infected with SARS-CoV-2.

The lead author, Denis Logunov of the National Research Centre for Epidemiology and Microbiology (Russia) commented that "when adenovirus vaccines enter people's cells, they generate the genetic code of the SARS-CoV-2 spike protein", which causes the cells to produce this protein.

This helps, he said, to "teach the immune system to recognise and attack the SARS-CoV-2 virus" although "to form a strong immune response against the virus, it is important to provide a booster vaccine".

In this regard, Logunov pointed out that booster vaccines that use the same adenovirus vector "may not produce an effective response, as the immune system may recognize and attack the vector" and this "would prevent the vaccine from entering the body's cells.

This is why two different types of adenovirus vectors have been used "in an attempt to prevent the immune system from becoming immune to the vector".

The trials were conducted in two Russian hospitals with adults aged 18 to 60, who were isolated as soon as they registered for the clinical trials and remained in the medical centres for the first 28 days.

Among some of the findings, they found both formulations to be safe and well-tolerated, and the most common adverse events included pain at the injection site (in 58 percent of participants), hyperthermia (in 50 percent), headache (in 42 percent), asthenia (in 28 percent), and muscle and joint pain (in 24 percent).

Following the experiments, the scientists considered that using different adenoviruses is an effective approach to trigger a "robust immune response" but warned that further research is still needed.

On the 'limitations' of the study, they included the short follow-up period (42 days); that it was a 'small' investigation; that some parts of the first phase of the trials included only male volunteers and that there was no placebo.

In terms of the next steps in the research, Professor Alexander Gintsburg from the centre said that phase three of the vaccine clinical trial will include 40,000 volunteers from different age and risk groups and will be carried out with constant monitoring.

Epidemiologist Naor Bar-Zeev, from the International Center for Vaccine Access (USA), who is not involved in the research, warned that all the vaccine candidates must show "that they are safe and prove lasting clinical efficacy (including in higher risk groups) in large randomised trials before they can be used".

The World Health Organization (WHO) said today that mass vaccinations against COVID-19 will most likely have to wait until mid-2021. "Realistically, we do not expect to see mass vaccinations until the middle of next year," WHO spokesperson Margaret Harris told reporters today.

Realistically, we don't expect to see mass vaccinations until the middle of next year," Margaret Harris told the press today. She said six to nine vaccine candidates are in advanced stages of research, with some in Phase 3 clinical trials, which require the participation of 30,000 or more volunteers and from which efficacy information is extracted and confirmed as safe.

The race to develop a vaccine against COVID-19, which has seen dozens of pharmaceutical and biotech firms launch, has generated both hope and confusion about the timeframe in which one or more vaccines might actually be available to the public.

Harris acknowledged that this confusion exists and that it has been partly fuelled by the fact that people are being vaccinated as part of clinical trials being conducted with several candidate vaccines, but it is not known whether they actually work.

"The different research groups are vaccinating people, but at the moment we don't have a clear signal that a sufficient level of efficacy and safety has been reached," explained Harris. He added that, given the resources that are being put into this, it is very likely that more than one vaccine will end up being available and that those that do come to market could be used in different population groups.

However, Harris acknowledged the danger of "raising false hopes" among the population because this can "increase complacency" about the virus and cause basic prevention gestures, such as social distance, mask wearing and hand washing, to be neglected. "Let's remember that at the beginning of this pandemic many people downplayed it and said it would be over soon. That attitude has led us into very difficult times," said the spokesperson.

His words were reminiscent of the positions taken by political leaders, such as the presidents of the United States, Donald Trump; or Brazil, Jair Bolsonaro, who minimised the severity of the coronavirus when it began to circulate in their countries. Eight months after the discovery of the new virus, the USA and Brazil are the countries-in that order-with the most cases and deaths from COVID-19 worldwide.

Faced with impatience around the search for a vaccine, Harris said that phase 3 clinical trials take the longest time, but must be well conducted to fully understand the level of protection offered by the vaccine and its level of safety. He added that the results of different vaccine candidates should be compared to see which is the best, and to do that, research data should be shared.

China and Russia claim to have discovered vaccines that work against COVID-19 and have indicated that they have started using them in their populations or are about to do so, even though they have not completed phase 3 clinical trials. Harris was unable to confirm whether the WHO has received the scientific data it has requested from Russia on its vaccine.