Asymptomatic omicron infections explain the high number of infections
(CNN Spanish) — The omicron variant of the new coronavirus continues to leave scientists with more questions than answers. Not only has it managed to circumvent the antibodies against covid-19 due to previous infections, but it also generates asymptomatic cases.
In this episode, Dr. Elmer Huerta discusses a new study published in JAMA that addresses precisely these infections.
You can listen to this episode on Spotify or your favorite podcast platform, or read the transcript below.
Hi, I’m Dr. Elmer Huerta and this is your dose of information about the new coronavirus. Information that we hope will be useful to take care of his health and that of his family.
The omicron variant circumvents antibodies from previous infections
As we have heard in previous episodes, in addition to the characteristic that the omicron family viruses have of circumventing the antibodies produced by previous infection and vaccines, this lineage of viruses is capable of being very contagious.
The consequence of these two characteristics is that the number of infections caused by omicron is very high in almost all the countries that report their data.
The point is that, in addition to these biological characteristics of the virus, there are other conditions in society that contribute to the explosive increase in cases of covid-19 that are being observed with viruses of the omicron family.
For example, the behavior of the population in relation to the use of masks and the observance of attending closed and unventilated spaces can also explain the greater increase in cases.
In this context, there is an element that, despite having been considered as a cause of the increase in cases, has been difficult to evaluate. It is the one that refers to the number of people who may be sick, have not realized that they are infected and are obviously contagious.
Today we will see a published study in the journal JAMA, of the American Medical Association and dated August 17, 2022, which precisely quantifies the proportion of people infected with the omicron variant, who did not know they were infected.
The study, carried out in the city of Los Angeles, analyzed the data of 6,385 people, all of them employed in an academic hospital center and participants in a study designed to find out — through blood tests — whether or not they were infected with SARS. CoV-2.
Let us remember that blood tests, called serological, measure the antibodies or immunoglobulins produced by the defense system when a person is infected or when they are vaccinated.
Precisely to distinguish the antibodies produced in response to a vaccine or an infection, the researchers measured the concentration of a special antibody, called anti-nucleocapsid, which is produced only when a person has been infectedbut not when you have been vaccinated.
That way, if a person is found to have anti-nucleocapsid antibodies, it only comes from an infection, and not from a vaccination.
All participants, with a mean age of 51 years and 65% women, answered questions about their health status at various intervals throughout the study.
Of the more than 6,300 participants:
- 2,479 people complied with the blood test and of them,
- 264 had serological evidence that they had been infected with the omicron variant.
Of those 264 people with evidence of having been infected, 54 were excluded for not completing the study requirements, so the analysis was done on the remaining 210 volunteers, of whom 94% had been vaccinated.
The omicron variant and symptoms: study results
Analysis of questionnaires in which participants responded to the presence of respiratory symptoms indicated that 92 of those 210 infected people (44%) did realize they had been infected. While the majority, that is, the remaining 118 or 56%, did not realize that they had had covid-19. In the few who did have any symptoms, he attributed it to a cold.
The authors conclude that a large proportion of infections caused by the omicron variant can be explained by the fact that people do not realize that they are infected, which obviously prevents them from taking precautionary measures to avoid contagion.
They also say that the increased use of home antigen tests could help people who suspect they have had an opportunity to discover if they are infected and initiate precautionary measures.
Do you have questions about covid-19?
Send me your questions on Twitter, we’ll try to answer them in our next episodes. you can find me at @DrHuerta.
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