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Why Hitting Pause On A Vaccine Trial Is A Good Thing

  • 3 min read

Sometimes, hitting the pause button is a good thing. Especially when you’re working on a lifesaving vaccine during a pandemic…

News of the recent suspension of the so-called Oxford trial in the UK after one of the participants fell ill sparked concern around the world, including in South Africa which is one of four global centres trialling the highly-anticipated ChAdOx1 nCoV-19 vaccine. It raised questions about whether vaccine trials are in fact safe, and whether the upset would scupper the entire project.

But, says Caryn Fenner, technical director of local biotech startup Afrigen Biologics, the suspension in fact provided welcome reassurance that the highest safety standards are being applied to this all-important experiment. “The decision to pause the trial means that the very highest clinical practices and necessary safety protocols are in place,” she stresses, adding that when such a trial is put on hold, the data is independently reviewed by a safety committee.

“We have to remember that often a participant falls ill due to causes unrelated to the trial. Half of the recipients are receiving the placebo, so if they do fall ill, it may have no relation to the vaccine trial.” The results of the review are then sent to the regulatory authority of the country in which the incident occurred, in this case the Medicines and Healthcare products Regulatory Agency (MHRA) in the UK.

Fenner says South Africa, along with Brazil, the UK and the United States, were proactive in getting involved in the trial due to the importance of understanding the effects of the vaccine within our local context. “It’s not enough to test the vaccine in higher-income populations. We need to know how it will work across diverse economic, ethnic and age groups,” she explains. And this rigorous testing is one of the reasons why it can sometimes take between 10 and 15 years for a vaccine to come to market.

A substantial amount of work is done even before a small cohort of patients are introduced in Phases 1 and 2 of any clinical trial. In Phase 3, which is where the Oxford trial is currently, the cohort is expanded, with thousands of participants tested to ascertain the potential for adverse effects across a broader cross-section of ethnic groups. This phase is also when the vaccine’s efficacy is tested in respect of comorbidities such as tuberculosis and HIV.

“However, this process can be accelerated during a pandemic, making people somewhat nervous that a faster timeline could mean that safety protocols have been overlooked. I think the Oxford trial illustrates that this is not true, and that the highest safety standards are always applied,” says Fenner. The Oxford trial was given the green light to resume within four days of the participant falling ill.

Afrigen Biologics has a reputation for its collaborative work on vaccines, and is involved in a long-term clinical trial for a therapeutic TB vaccine. While adjuvants – an adjuvant enhances the immune system’s response to vaccine antigens – are its core business, the company also applies the same technology it uses for vaccine adjuvants to other healthcare products such as complementary medicines, vitamins and minerals, which have a faster route to market. Afrigen recently launched the Nanozomal™ CBD+ range, which is a premium quality, highly absorbable cannabidiol (CBD) product with their partner BioDelta Nutraceuticals.