Nigerian virologist, Dr Solomon Chollom, on Thursday warned against the use of Russian Coronavirus (COVID-19) vaccine, Sputnik V, stating that it has not gone through entire clinical trials protocols.
Chollom told the News Agency of Nigeria (NAN) in Abuja, that this should be a cause for concern for all health care practitioners and the Nigerian public.
According to him, it is only the full clinical trials that will guarantee evidence-based approval from regulatory bodies and confident use by professionals.
He said that for the purpose of clarity, vaccine development was a combination of intensive laboratory-based work and extensive field or clinical trials to generate evidence around safety, efficacy and potency.
”We are expressing our interest for the COVID-19 vaccine so that we will have the opportunity to work elaborately,” he said.
Chollom said that clinical trials for vaccines are in four phases.
“Phase one has to do with administration of the candidate vaccine to a very small group of healthy volunteers to assess safety parameters.
”At this stage, the bioavailability and tenure of the vaccine in the target area is also assessed.
“Phase two is usually carried out subsequent to the success of phase one trials.
”A larger group of healthy volunteers is usually mobilised and administered the vaccine and then exposed to the disease-causing agent to assess if they will come down with the disease or stay protected by the administered vaccine.
”This phase is out to generate evidence around the effectiveness (efficacy) and dosage of the product,” he explained.
Chollom said that the success and proven evidence from Phase two would guarantee the Phase three trials.
“Here, the trial is done in a very large population, usually a multi-national study involving volunteers in thousands.
”This stage is peculiar because it brings on board different races, demographics and other possible human and environmental factors under scrutiny.
”Safety, efficacy and most importantly, potency are assessed on a larger scale across many parameters; some are host-specific and others environment-specific.
“Phase III trials usually take a long time. After successful and proven evidence from this phase, regulatory bodies are at liberty to approve the drug for clinical use,” he said.
Chollom said that the last phase was the Phase IV trials. This, he said was usually done as postmarket evaluation/validation of claims on the vaccine.
He said that parameters of safety and efficacy along with emerging realities in the population were generated during this phase in real life experience.
The virologist said that this was critical to monitor safe and efficacious use of the vaccine, adding that Scientists were curious that the Russian vaccine was at best a fast food.
He said this was because it had not gone through the gamut of protocols to generate rounded scientific evidence to convince the world on safety (especially long term adverse effects on essential human organs or the possibility of reversion to a virulent strain or the virus.
Chollom said that the efficacy and potency of a vaccine, given stiff competition from both host and environmental factors that might not have been envisaged.
According to him, this caution is timely in light of the disturbing development over the re-emergence of polio virus in Sudan and Republic of Chad arising from the administration of oral polio vaccine.
“This is coming barely two weeks after Africa was given certificate of freedom from polis virus by World Health Organisation (WHO),” he said.
Chollom, however stated that a little compromise in the process of vaccine development could have severe consequences on safety, efficacy and potency of the vaccine.
He also drew attention to the emerging development as reported by Associated Press that AstraZeneca has put on hold late-stage clinical trials of another Corona vaccine trial as a volunteer in the exercise developed a strange illness.
“The body reported that the halt in the trials was in tandem with global best practices to unravel the cause of the untoward reaction by the volunteer as it raises sincere questions on safety.
“Such is the meticulousness involved in vaccine development process” Chollom added.