Experts explain to CNN Portugal that for several months there have been no cases of this multisystemic syndrome associated with covid-19 in children, a disease which, they warn, can be fatal.
Covid-19 vaccines and characteristics of the Ómicron variant have slowed cases of MIS-C in Portugal, the multisystem inflammatory syndrome associated with SARS-CoV-2 in children and who had a increase in cases during delta propagation. Specialists in pulmonology and pediatrics assure CNN Portugal that serious cases of the disease have not been detected in hospitals for several weeks, even with the general increase in infections during the pandemic. sixth wave.
The president of the Portuguese Society of Pediatric and Medical Cardiology at the Centro Hospitalar de São João, Maria João Baptista, says there has been “a clear decrease” in MIS-C cases in recent months and that in her unit “there there have been no cases for several weeks”. This decrease, he explains, was “gradual” and totally different from what happened in 2021, the year in which 33 children with the syndrome were hospitalized, including nine in intensive care.
every time it happens a new spike in covid-19 infections“usually this is accompanied by an increase in cases of MIS-C”, notes however Maria João Baptista, “the increase in the number of cases of covid-19, with the end of the compulsory wearing of the mask and with the easing of restrictions, has not been verified in MIS-C cases”.
This scenario is in line with a recent study carried out in Denmark and which was published on June 8 in the scientific journal JAMA Pediatrics. It describes that the risk of a child suffering from MIS-C after infection with the Ómicron variant is “significantly lower” than in other strains, such as Delta, and that the risk of contracting the multisystem syndrome is “significantly lower in children. and adolescents who have been vaccinated compared to those who have not been vaccinated”.
“This is the great strength of this study,” explains Manuel Magalhães, pediatric pulmonologist at the Centro Materno Infantil do Norte and Lusíadas do Porto Hospital, who has also not registered a case of MIS-C “for several weeks”. For the doctor, the work carried out in Denmark “clearly shows that the vaccine protects a lot against this MIS-C, one of the most serious diseases that exist”. “What this study shows is that those who are vaccinated have ten times greater protection against MIS-C than those who are not,” he points out.
On the other hand, the study also shows that Ómicron produces ten times fewer cases of MIS-C in unvaccinated children. Indeed, as Maria João Baptista explains, there is “less aggressiveness on the part of the variant”, which is “less capable of triggering an exuberant inflammatory response”.
Reduced risk of reinfections
The doctor also points out that there is a much lower risk of a child developing MIS-C when reinfected with covid-19, because, “if there is a new infection in a child, a prior exposure to the virus causes the immune system to have memory and makes development of the syndrome much less likely.
Besides the characteristics of Ómicron and the vaccination campaign, there are other reasons why MIS-C seems to be slowing down in the country, explains doctor Manuel Magalhães, pointing out the development of natural immunity and the “seasonal variation of environmental factors”. . , such as temperature, sun exposure and humidity that influence the transmission of SARS-CoV-2”.
Even so, Maria João Baptista and Manuel Magalhães guarantee that the possibility of registering an increase in MIS-C cases must be taken into account, since it only takes one case to be “pretty serious”, says the Centro doctor Materno Infantil du Nord, and being able to generate “long-term consequences for children that we do not yet fully know”.
Maria João Baptista also recalls that MIS-C is a disease characterized by inflammation of different organs, “including the heart, lungs, kidneys, brain, skin, eyes and gastrointestinal organs”, which appears in children and adolescents who have been exposed. to SARS.-CoV-2. Not being a frequent disease, adds the president of the Portuguese Society of Pediatric Cardiology, “affecting less than 1% of children infected with covid-19”, it can be very serious or even fatal. “The literature tells us that up to 70% of children with MIS-C may need intensive care, with a mortality rate of between 1 and 2%,” says Maria João Baptista.