Following the news that Russia has approved the first COVID-19 vaccine;
Philipp Rosenbaum, PhD, Senior Infectious Diseases Analyst at GlobalData, a leading data and analytics company, offers his view:
“The available clinical trial data for Russia’s COVID-19 vaccine, comprising 38 trial participants that have been followed for two months, is simply not enough to convince the global community of this vaccine’s potential. Only large-scale trials with longer duration can determine if the vaccine can protect against SARS-CoV-2 with a durable response while being safe – the latter being especially important when it is planned to be given to hundreds of millions of people.
“Saying that, the Gamaleya vaccine may well work – it is based on adenovirus vectors Ad5 and Ad26, similar technology to which have shown good signs – but the push for such speed is likely being fueled by political aims. Being the first country to successfully develop a COVID-19 vaccine would be a big boost economically and for the country’s morale, since Russia has seen the fourth most number of confirmed COVID-19 cases. Companies and regulatory agencies from the US and China have both noted that a longer study than Russia has conducted is necessary to demonstrate protection, as well as pointed out that standards for clinical trials are not as transparent in Russia as in other countries.
“Gamaleya is planned to be offered out in stages, with Russian health workers treating COVID-19 patients and Phase III participants getting first access. It is unclear when enough vaccine doses will be available in the country for the start of mass-vaccination, making this approval announcement less impactful. Collaborations with other countries for the production of ‘Sputnik V’ – as the vaccine will be called internationally – are planned, but other countries will likely wait for additional protection and safety data before rolling out the vaccine. In China for example, multiple vaccines have shown some form of efficacy; however, China did not approve any of them, likely because regulators well understood that these data are insufficient for determining overall effectiveness. That said, China has begun using CanSino’s COVID-19 vaccine, but only in the military, and this was not touted as approval.
“In addition to the lack of long-term durability data, the use of adenovirus vectors poses the risk of reduced vaccine efficacy due to high pre-existing immunity to the viral vector, as studies of CanSino’s vaccine have shown. These vaccines will be very useful as first-generation vaccines to slow the spread of SARS-CoV-2 and disease, but if no long-term immunity can be achieved with two doses of the adenovirus vector-based vaccine, it is unclear whether annual vaccinations using this technology will offer sufficient protection going forward.“