" The results of clinical trials of the Russian vaccine Sputnik V have demonstrated impressive results, which have now been recognized by the international medical community. The vaccine has been shown to be safe and effective with no serious side effects identified and uses a proven platform based on human adenoviral vectors, which is currently the safest mechanism for introducing the genetic code of the virus spike into the human body. This approach has been thoroughly studied not only in Russia but also internationally. Russia has a long and successful track record developing vaccines and remains a global leader in this field. We hope that the vaccine will soon become available across the world to help stop the devastating pandemic and enable people to return to normal life. "

"The two studies by Logunov and colleagues have several strengths. First, adenoviruses are ubiquitous, so humans might not be immunologically naive. A second strength is the threshold for neutralisation used in the two studies. A third strength is that the vaccine, similar to other before it, induced broad immune responses. Although not specifically discussed, the results imply a T-helper1-cell-weighted response that might be important for vaccine safety, potentially reducing the risk of antibodydependent enhanced disease. A fourth strength was development of two vaccine formulations, frozen and lyophilised. A lyophilised formulation could mean stability within the existing global vaccine refrigerated cold chain that is needed to maintain vaccine efficacy from factory to recipient, a hurdle other vaccines are yet to address. Although more costly to produce at scale, product stability will maximise reach in remote terrain, a must if universal and equitable coverage is to be achieved."

"There are features that make Sputnik V a promising candidate. The idea of using two different adenoviruses as vector is superior over many vaccines in the frontline. Generally, the immune system perceive the vector proteins as antigen similar to the S protein of SARS-CoV-2, so it elicit immune response against those proteins as well. If people are reimmunized (as second dose or repeated vaccine), the pre-existing immunity can compromise the efficacy of second vaccine dose. Using a vector of different nature, as is the in Sputnik V, will avoid this problem."

"The data on the Russian vaccine studies reported in the Lancet are encouraging - demonstrating the safety and immunogenicity of the adenovirus-based COVID-19 vaccines."