Two new members of the Omicron family, BA.4 and BA.5, seem to be responsible for the increase in coronavirus infections in many countries, with the relaxation of hygiene measures.
Mostly in South Africa and Portugal, these mutations are causing uncertainty in the face of a new wave of covid-19 in the months ahead.
Where are they located?
These new omicron subvariants, identified in early April by researchers from Botswana and South Africa, appeared likely between mid-December and early January.
After becoming the majority among new cases in South Africa and Portugal, they are now the protagonists of new waves of the pandemic.
In South Africa, where “BA.4 and BA.5 were first detected, where BA.5 is currently most prevalent, the peak of the pandemic ended in mid-May and its impact was moderate. BA.5, Most importantly, the incidence “in Portugal, a country where it is increasing, albeit at lower levels than in the previous wave,” the French Public Health Agency announced on Friday.
And the increase in cases is now threatening other countries.
In Europe, strains BA.4 and BA.5 are increasingly common in France and are expected to surpass the main strain BA.2 since the beginning of the year. The French health institution confirmed the acceleration of cases with its latest weekly figures and the increase in these two sub-variables.
A situation similar to what happened in Germany and England.
According to experts, the end of sanitary control measures supports this increase in infections.
Are they more contagious?
The two subvariants appear to spread even faster than previous omicron mutations.
“BA.4 and BA.5 can spread faster than BA.2 due to the double advantage: reduction in transmission factors and immune protection. Therefore, BA.4 and BA.5 trigger a faster wave than BA.2” , AFP Mircea T., a professor at the University of Montpellier in the south of France, explains to Sofonea.
In Europe, spending more time outside in summer (northern hemisphere, winter in Brazil) could put a brake on the increase in cases. But this epidemiologist prefers to be cautious: “We can count on summer to leave a lower incidence than winter, but this alone is not a factor that could prevent a wave of infections as seen in the delta in July 2021.”
Are they more dangerous?
The scientists note that so far there have been no warning signs that BA.4 and BA.5 are more severe than previous subvariables. But “it’s too early to know,” explains Mircea T. Sofonea.
But what has been seen in South Africa and Portugal suggests some experts have lower risks of hospitalization and death.
“The BA.4/5 wave in South Africa did not translate into more hospitalizations and deaths because there was more immunity in the population,” tweeted Tulio de Oliveira, a virologist at the University of Kwazulu-Natal in South Africa. Omicron was detected in the fall of 2021. “But we don’t know the long-term effects…”
In Portugal, the vaccination rate is higher, but the population is older, hospitalizations have reached the levels of the previous wave.
However, unlike other countries, South Africa and Portugal were not affected by BA.2.
The French Public Health Agency said in May that the presence of BA.2 in a country could “provide greater protection against BA.4 and BA.5” because they are “genetically close”. Although this is something that has not yet been confirmed.
In either case, immune protection diminishes over time.
“The protection afforded by being infected with Omicron or getting the third dose of the vaccine decreases against any infection after five months, although it is still significant against particularly severe forms,” Sofonea stressed.
Some countries, such as Brazil, recommend a fourth dose for the most vulnerable people.
And although it is not mandatory, experts continue to recommend the use of masks in different situations.
source: Noticias
[author_name]
