MOSCOW (Reuters) – A Russian trial that tests the effectiveness of revaccination with the Sputnik V injection to protect against new coronavirus mutations is producing solid results, the researchers said on Saturday.
Last month, President Vladimir Putin ordered a review by March 15 of vaccines produced in Russia for their effectiveness against new variants that spread in different parts of the world.
“(A) A recent study by the Gamaleya Center in Russia showed that revaccination with the Sputnik V vaccine is working very well against new coronavirus mutations, including coronavirus strains from the UK and South Africa,” said Denis Logunov, deputy director of the center, who developed the Sputnik V shot.
The test results are due to be published soon, but this was the first indication of how the tests are going. No additional details were available yet.
So-called viral vector injections – such as Sputnik V and an injection developed by AstraZeneca – use harmless modified viruses as vehicles, or vectors, to carry genetic information that helps the body build immunity against future infections.
The revaccination used the same injection as Sputnik V, based on the same adenovirus vectors. The trial indicated that it did not affect effectiveness, Logunov said in a statement to Reuters.
Some scientists have raised the possible risk that the body will also develop immunity to the vector itself, recognizing it as an intruder and trying to destroy it.
But the developers of Sputnik V disagreed that this would pose long-term problems.
“We believe that vector-based vaccines are actually better for future revaccination than vaccines based on other platforms,” said Logunov.
He said the researchers found that antibodies specific to the vectors used by the injection – which could generate an anti-vector reaction and impair the work of the injection itself – decreased “as early as 56 days after vaccination”.
This conclusion was based on a trial of an Ebola vaccine previously developed by the Gamaleya Institute using the same approach as the Sputnik V vaccine.
Vector immunity is not a new problem, but it is under renewed scrutiny, as companies like Johnson & Johnson predict that regular COVID-19 vaccinations, such as annual flu vaccines, may be needed to combat new variants of the coronavirus.
(Reporting and writing by Polina Ivanova; Editing by Frances Kerry)