The new COVID BA.4 and BA.5 variants, under scrutiny for their ability to bypass vaccine immunity and infection

The sublineages of omicron BA.4 and BA.5 of COVID-19, much more contagious, already represent half of the samples analyzed in the Community of Madrid and is “very likely” that this variant becomes majority “in a few weeks”.

This has been indicated by the Deputy Minister of Health Care and Public Health, Antonio Zapateroin a message on his personal Twitter account in which he points out that this circumstance “explains the current situation of increased transmission“.

The European Center for Disease Control and Prevention (ECDC) already pointed out this week that these subvariants of omicron will become “dominant” throughout the European Unionwhich “will likely lead to an increase in COVID-19 cases in the coming weeks.”

In Spain, BA.4 and BA.5 represented more than 10% of the samples analyzed by variant-specific PCR in 10 autonomous communities during the last weeks, with a wide variation between Autonomous Communities.

In a report, the ECDC details that, in any case, “no test” that variants BA.4 and BA.5 are associated with increased severity of infection compared to the BA.1 and BA.2 variants, currently the majority in circulation.

The report hints that his biggest infection may have to do with his ability to “evade immune protection against infection induced by previous infection and/or vaccination“This raises more concerns about BA.4/BA.5 infections than BA.1/BA.2, as well as Omicron reinfections,” they add, although they reassure that transmission “continues to decline.” throughout the European environment.

“However, as in previous waves, an increase in COVID-19 cases in general can lead to increased hospitalizations, ICU admissions, and deaths“, warns the European body.

The BA.4 and BA.5 variants were first detected in Europe in March. Portugal it was the first country to observe a significant increase in cases and in the proportion of one of these two variants (BA.5). As of May 30, BA.5 is the dominant variant in Portugal, with an estimated share of around 87%. However, data from recent weeks suggests that the peak of the BA.5 wave may have been reached.

In recent weeks, an increase in the proportion of BA.4 and BA.5 infections has been observed in many European countries, including Spain, Germany, Austria, Belgium, Denmark, France, Ireland, Italy, the Netherlands and Sweden.

In particular, in Belgium BA.5 reached an estimated proportion of 19% and BA.4 represented 7.5% of the sequenced genomes. In the Netherlands, BA.5 reached a proportion of 8%, while BA.4 was detected in a proportion close to 5%.