There is no significant difference in the viral load of the coronavirus Delta variant between vaccinated and unvaccinated infected persons, nor between symptomatic and asymptomatic persons, according to a new American scientific study.
The researchers, led by Dr Richard Mitchelmore of the University of California-Davis, who made the pre-publication in medRxiv (there has not yet been a regular publication in a scientific journal), according to Reuters, analysed data on 869 patients diagnosed with coronavirus, of whom 632 were asymptomatic. Most were infected by Delta variant of the virus.
The study of the viral load of each individual found no significant difference in the mean viral load between vaccinated and unvaccinated individuals, neither between those with and without symptoms, nor by other criteria (age, sex, type of vaccine). Approximately one in five (20%) coronavirus positive vaccinees were found to have a high viral load and, of these, one in three were asymptomatic. This was also observed in children under 12 years of age, so they were probably contagious, which, according to the researchers, justifies testing the students.
«Our study does not provide information on transmissibility», stressed Mitchelmore, clarifying that the transmission of coronavirus is influenced by several factors, not only by the viral load or whether someone has been vaccinated. «However, it is not right to assume that because someone has been vaccinated, they cannot become infected themselves or infect others, even if they are asymptomatic,» he added.
As other studies have shown, Covid-19 vaccines reduce the chance of infection even for others with whom a vaccinated person comes into contact, but there is always the possibility that the latter will either become infected with the coronavirus (so-called breakthrough infections) or spread it to others. For this reason, the researchers stated that, although vaccination is the best protection, given the not insignificant proportion of asymptomatic breakthrough infections among vaccinated persons, vaccinated persons should probably continue to wear a mask in certain places and to take other precautions, which is particularly important for unvaccinated persons.
