Not only a shield effect against Covid, but also a lower viral load in cases where the virus still manages to infect. It is the possible ‘double strike’ of the Coronavirus mRna vaccine. Some initial reports have photographed it and suggest a lower infectivity of those who become positive after being vaccinated. Specifically, a study published in ‘Nature Medicine’ takes into consideration this potential of the Pfizer vaccine. Approximately 95% effective in preventing symptomatic disease from approximately 7 days after the second dose, the shield product also provides early protection starting 12 days after the first injection. But what if someone becomes infected in this time frame?
The work analyzes a set of (real-life) data on Sars-CoV-2 positive tests after vaccination. The authors found that “viral load is substantially reduced for infections occurring 12-37 days after the first dose of the vaccine,” reads an excerpt from the research. “These reduced viral loads suggest potentially lower infectivity“, a lower contagiousness that” further contributes to the effect of the vaccine on the spread “of Covid-19.
The study was conducted in Israel. The authors, researchers from the Technion – Israel Institute of Technology and Maccabi Healthcare Services (Mhs), exploited a dataset obtained thanks to the fact that the MHS vaccinated over 1 million people as part of a rapid national launch of the Covid shield injection. By also running tests in the central laboratory, this provided an opportunity to monitor post-vaccination infections.
“In addition to the substantial protection of vaccinated subjects – explain the authors – the anti-Covid vaccines could reduce the viral load in infections” that occur after shield injection “and thus further suppress subsequent transmission” of the virus. “As countries are rushing to vaccinate a substantial portion of their population in the coming months, it is hoped that the virus’ base reproduction number”, ie the contagion rate “will decrease. This effect can be achieved by reducing the number of people. susceptible, as well as reducing viral load. The effect of vaccination on this aspect, ie on viral load in post-vaccination infections, is currently unknown “, note the experts.
To learn more, the researchers then looked at the Ct value (cycle threshold), which indicates how many amplification cycles must be performed to detect the presence of viral Rna in a buffer. A very high Ct value signals a lower viral load. The observed population was 4,938 people. The researchers observed lower viral loads in tests that turned positive after the 12th day after the first dose and also significantly lower viral loads when compared to those found in the unvaccinated population.