Once again there is a new omicron variant: the subtype BA.5. This could soon be responsible for a large part of the new infections. How worrying is the situation?
Infections with the latest omicron variant BA.5 are increasing. That is why the World Health Organization (WHO) classifies this omicron subtype as at least of concern. The German Robert Koch Institute (RKI) expects BA.5 and other omicron subtypes to continue to spread rapidly because they are more easily transferrable than was the case with Delta. The institute warns of an increase in infections this summer.
“The currently strongest growth is shown by the proportion of the BA.4 and BA.5 sublines,” reported the RKI on June 9th. The Institute concludes that these two new omicron variants could soon be responsible for the majority of cases. The BA.5 variant already accounts for ten percent of current infections. That’s twice as many as a week earlier, in early June.
BA.5 first appeared in South Africa
The BA.5 variant had already raised concerns in South Africa in early May. However, the wave was smaller than the previous one and is already subsiding. In Portugal, however, the new subtype Omicron BA.5 is already responsible for 80 percent of all new infections. The hitherto unknown sub-variant is more contagious than its predecessors. It cannot be recognized as well by the neutralizing antibodies and can spread more quickly. However, the gradients are milder than with Delta, for example.
Do booster vaccinations protect against infection with omicron variants?
The protection provided by the corona vaccine decreases over time as antibody levels drop. The same applies to people who have gone through a corona infection. Even those who have been vaccinated and those who have recovered do not have optimal protection against new omicron subvariants and can become infected again. BA.5 has already gained a foothold in several countries – such as Portugal – where the number of new infections has risen sharply within a very short time.
New infections with subvariants are therefore possible despite vaccination and/or past infection and occur more frequently than with the Delta variant.
But there are fewer deaths and hospital admissions. According to experts, this is because many millions of people are now vaccinated and have antibodies, even if the levels are not consistently high. General immunity is higher than at the beginning of the pandemic. Nevertheless, the RKI recommends risk groups and older people in particular to have another booster vaccination to increase the number of antibodies again.
More infections but less deadly
The vaccines were administered to target the variant of the spike protein that was active at the beginning of the pandemic. However, the virus has now changed in such a way that the antibodies no longer respond so well to the vaccine. Fewer antibodies are formed and the virus can evade them more easily.
But the new variants, including BA.5, seem to be less dangerous. One theory is that the variants can affect the upper respiratory tract very quickly and massively, but the lung cells are affected less frequently. Fewer people die. In the early infections, the lungs were much more severely affected, resulting in more deaths.
Protection against infection with omicron
At around three days, the time between the actual infection and the first symptoms is shorter in Omicron than in the Delta variant. The protection that current vaccines offer against infection with omicron is not optimal, but they still protect against severe cases. Basic immunization is probably sufficient for this. A booster vaccination ensures that more antibodies are formed again. There is better protection again.
Although omicron with its various subtypes is usually much milder than delta, severe symptoms can also occur in rare cases. And: It is not yet clear what long-term consequences an omicron infection can have.