This Monday the Government of Mexico City started managing the booster dose from Covid-19 vaccine to adults from 40 to 49 years old, in the 16 municipalities. People in this age group will be given component 1 of the vacuna Sputnik V, developed by the Instituto Gamalea de Rusia.
When giving the announcement, last Friday, January 28, Eduardo Clark Garcia Dobarganes, director of Digital Government of the Digital Agency for Public Innovation, indicated that the capital’s government has already received authorization from the Federal Commission for the Protection against Sanitary Risks (Cofepris) to apply the first component of the Russian vaccine as a booster for all the vaccines applied in the City.
For its part, the Secretary of Health of the CDMX, Oliva Lopez Arellano, indicated that the first component of the Russian vaccine will be used on this occasion, since Sputnik V is the vaccine that is available.
“All the vaccines are already recommended in their different combinations, so it is safe to apply component 1 of Sputnik V as a booster,” he said.
Given the rapid spread of Omicron coronavirus variant, the need has been seen to apply a booster dose, apart from the complete vaccination schedule against Covid-19, to counteract the possible decrease in antibodies against this disease that the vaccines could have after a few months.
How effective is the Sputnik V vaccine against Omicron?
According to a small preliminary independent study conducted by the Spallanzani Italian Institute, the levels of Omicron neutralizing antibodies in people immunized with the Russia’s Sputnik V vaccine did not decrease as much as those of those who received injections of Pfizer.
In the study, which was carried out by a team of Italian-Russian researchers representing the Institute and the Gamaleya Center, it was found that the Sputnik V vaccine shows a significantly lower reduction in virus-neutralizing activity against Omicron compared to the Wuhan reference variant than the Pfizer vaccine.
The study notes that 100% of people vaccinated with Sputnik V were able to neutralize the Omicron variant compared to 83.3% of people vaccinated with Pfizer.
The trial included 51 people vaccinated with Sputnik V and 17 after two injections of the Pfizer vaccine.
The study, which will seek certification by peer review, showed that Omicron-specific neutralizing antibodies were detected in the blood serum of 74.2% of people vaccinated with Sputnik and 56.9% of those vaccinated with Pfizer/BioNtech.
Sputnik Light, as a booster shot
According to preliminary data from a study conducted by the Gamaleya Institute, using Sputnik Light (the one-dose version of the vaccine) as a booster for the Sputnik V vaccine increases the virus neutralizing activity against Omicron significantly 2 to 3 months after receiving the serum-based booster dose.
The study indicates that the expected efficacy against Omicron of the vacuna Sputnik V added to the reinforcement of Sputnik Light, it could be greater than 80%, since Sputnik V showed an efficacy of more than 80% against wild strains of the virus 6 months after vaccination.
The Gamaleya Institute reported that the preliminary study reveals that 100% of the individuals who received the biological Sputnik Light as a booster developed neutralizing antibodies against Omicron and demonstrated to maintain a high level 2 to 3 months after its application, compared to only 25 % of people who received the Pfizer booster who showed a detectable level of neutralizing antibodies 3 months after being vaccinated.
In a communication released last December, the Institute indicates that it is recommended to use Sputnik Light as a booster to strengthen the efficacy of other vaccines, including Sputnik V, against Omicron.
It should be noted that this study has not been peer-reviewed and the samples analyzed are of a relatively small number; and more studies are needed to understand the efficacy of Covid-19 vaccines against the Omicron variant of SARS-CoV-2.