Since then, several countries in Europe have announced new measures, such as lockdowns, the cancellation of mass events and travel restrictions around the world.
So far, omicron is known to be much more contagious than delta. The WHO confirmed on Monday, December 20, that there is evidence that people who have been vaccinated against covid-19 or those who were infected in the past can contract the omicron variant, whose spread is accelerating in the world.
WHO chief scientist Soumya Swaminathan said the variant is managing to evade some immune responses, meaning that booster programs being put in place in many countries should target people with weaker immune systems.
On the effectiveness of the. Vaccines, several studies have been published that indicate that almost all are less effective against this variant, although those made with the Messenger RNA technology (Pfizer / BioNtech and Moderna) may have an advantage.
Swaminathan asked to be very careful with these studies and “not to overinterpret the information on the (apparent) reduction in the effectiveness of the omicron vaccines”, as these laboratory studies do not take into account other aspects of the immune system of individuals who perform a extremely important role when it comes to protecting them against serious infection.
Although the antibody defenses of some courses have been weakened, there is hope that T cells, the second pillar of the immune response, can prevent severe disease by attacking infected human cells.
Most vaccine manufacturers have said they work on a special dose for omicron that would be ready in a few months.