Russian authorities have proposed trying a combination of British-Swedish drugmaker AstraZeneca's COVID-19 vaccine with Sputnik V to boost efficacy.
"Currently, full dose AstraZeneca regimen resulted in 62 percent efficacy. If they go for a new clinical trial, we suggest trying a regimen of combining the AstraZeneca shot with the Sputnik V human adenoviral vector shot to boost efficacy. Combining vaccines may prove important for revaccinations," the Sputnik V official Twitter handle said.
Sputnik V proposal came following reports about AstraZeneca's plan to run an additional global trial to assess the efficacy of lower dosing regimen of its vaccine.
Bloomberg News quoted AstraZeneca CEO Pascal Soriot as saying that the company is looking to conduct an additional global trial instead of adding a trial arm to its ongoing trials in the US after questions were raised over the results from its late-stage study.
In an interim analysis from the phase-3 trial, published earlier this week, AstraZeneca had reported 90 percent vaccine efficacy for a lower dosing regime and 62 percent for two full vaccine doses. However, AstraZeneca-University of Oxford researchers said the lower dosing was not by design but due to the result of an error in the quantity of vaccine put into some vials in the UK arm. This sparked wide criticism, with people calling the error as an embarrassment and the 90 percent efficacy as cherry-picking.
Frequently Asked Questions
A vaccine works by mimicking a natural infection. A vaccine not only induces immune response to protect people from any future COVID-19 infection, but also helps quickly build herd immunity to put an end to the pandemic. Herd immunity occurs when a sufficient percentage of a population becomes immune to a disease, making the spread of disease from person to person unlikely. The good news is that SARS-CoV-2 virus has been fairly stable, which increases the viability of a vaccine.
There are broadly four types of vaccine — one, a vaccine based on the whole virus (this could be either inactivated, or an attenuated [weakened] virus vaccine); two, a non-replicating viral vector vaccine that uses a benign virus as vector that carries the antigen of SARS-CoV; three, nucleic-acid vaccines that have genetic material like DNA and RNA of antigens like spike protein given to a person, helping human cells decode genetic material and produce the vaccine; and four, protein subunit vaccine wherein the recombinant proteins of SARS-COV-2 along with an adjuvant (booster) is given as a vaccine.
Vaccine development is a long, complex process. Unlike drugs that are given to people with a diseased, vaccines are given to healthy people and also vulnerable sections such as children, pregnant women and the elderly. So rigorous tests are compulsory. History says that the fastest time it took to develop a vaccine is five years, but it usually takes double or sometimes triple that time.
It's not the first time, earlier too the official Twitter handle of Russia's Sputnik V vaccine rival to AstraZeneca took potshots at the latter’s vaccine.
"The possible reason for 62 percent efficacy of AstraZeneca’s full dose regimen is that immunity to Chimpanzee adenoviral vector from the first shot makes the second shot ineffective. Sputnik V addresses this issue by using two different human adenoviral vectors for two shots," it says.