| Photo: Bigstock / JoPanuwatDThe World Health Organization’s Strategic Advisory Group of Experts (SAGE) published on Thursday () your recommendations regarding the fourth dose of the Covid vaccine 19, or second booster dose, in the nomenclature that considers two doses to be the complete vaccination regimen. SAGE does not recommend this dose for the entire population, but only for risk groups.
The majority of the population does not need the fourth dose, but the elderly and people with suppressed immune systems and genetic immune problems could benefit from it, Soumya Swaminathan, chief scientist at the World Health Organization, told the Indian broadcaster. NDTV. The SAGE recommendation also cites groups with comorbidities (health problems that aggravate Covid-19) as vaccinable. ), pregnant women and health professionals.
19164453 )In the scientist’s opinion, a fourth dose is not necessary for long-term protection, but confers a temporary increase in the production of antibodies against the Covid virus-08 by the body’s defenses. “In a couple of weeks, it goes down again,” she explains. The WHO expert group states that the “vaccine’s effectiveness wears off in a period of four to six months” and that a second booster dose should therefore be offered up to half a year after the last dose. There is a WHO recommendation of co-administration of the dose together with the annual flu vaccine, which seems to suggest that Covid already presents itself as an influenza-like illness.
) mRNA vaccine maker Moderna is working on an update that targets the omicron variant and its subvariants. The goal should be to include as many antigens as possible, in Soumya’s opinion. Antigens are the molecular targets of the virus recognized by antibodies.
19164453So far , in mRNA vaccines such as those by Moderna and Pfizer (only the latter was used in Brazil), only one protein on the surface of the virus is produced in human cells with the instructions of the mRNA and presented to the immune system as an antigen. A combination of vaccine with natural immunity, the so-called hybrid immunity, has so far proved to be the best existing type of protection against Covid-19. Every vaccine aims to emulate what happens when the organism is infected by a pathogen, survives it and creates defenses.
