How are the BA.4 and BA.5 omicron subvariants behaving that are causing the seventh wave of COVID in Spain?

The BA.4 and BA.5 omicron COVID-19 variant lineages were first detected in South Africa in January 2022, and have since become the dominant variants there, as explained by the European Center for Disease Prevention and Control (ECDC). In May 2022, cases began to grow in Portugalwhich already by then sequenced that BA.5 represented 37% of the positive cases in the country.

Now, the wave of new cases has reached Spain, which The incidence in people over 60 years of age has already skyrocketed above 1,300 cases. This is, in fact, the only conclusive data about this seventh wave, since the Health strategy contemplates that only those older than that age or people with severe symptoms notify their positives.

They can reinfect, although they are not more serious

One of the causes of this increase in cases could be behind the loss of immunity for people infected by omicron previously. The (limited) data from studies accessed by ECDC show that both BA.4 and BA.5 can reinfect unvaccinated people who have already experienced a previous BA.1 infection.

Regarding research with vaccinated people, indicates the European health organization, “although performed better in the in vitro studies carried out so farthe protection derived from the currently available vaccines decreases over time against the omicron variant”. With these data, the ECDC already pointed out in May the real probability of a generalized increase in COVID cases in the European Union and, despite that he ruled out an increase in the severity of infections, he did warn that these increases are usually followed by a certain level of increase in ward and ICU hospitalizations.

An end that confirmed the general direction of Public Health in a statement released last week. According to the Ministry of Health in the document, lineages BA.4 and BA.5 are expected to displace the omicron subvariant BA.2. However, he highlighted what the ECDC already pointed out two months ago: “Until now, none of them have been associated with an increase in the severity of cases.”

He also noted that “given its ability to partially evade the immune response generated by vaccines and prior infection (including infection by the BA.1 lineage) substitution of BA.2 by any of these lineages could be associated with an increased incidence of cases.”

“Currently, the effect on the impact is considered very low although a very marked increase in the incidence could lead to a high number of severe cases“, specified.

According to the conclusions of the Ministry of Health, these variants have shown a greater growth than that of BA.2 when it displaced the original omicron variant and there are already four investigations that show that the capacity to neutralize vaccinated people is lower for BA.4 and BA.5 than that observed for BA.2. It is also lower in vaccinated people who have suffered an infection by BA.1 or BA.2, who can suffer reinfections although, explains the Ministry, “in this case, the degree of decrease is less”.

Health Recommendations

The Minister of Health, Carolina Darias, has already asked to reinforce protection measures against COVID-19 in the face of this exponential increase in cases. Thus, she has asked the population “prudence” and the use of protection measures such as the use of masks in closed spaces and among the vulnerable population.

Darias has also appealed to citizens so that they come to get the booster dose of the vaccine, especially those under 50 years of age, and explained that the Conference on Vaccines will address the decision to inoculate those over eighty years of age with a fourth dose, deciding whether it will be done before autumn, as requested by Catalonia, or will wait for the that a beginning marked Health.