The WHO recommends keeping an eye on the BA.2 variant of Omicron because it is spreading, but it does not appear to cause more serious disease or escape vaccination. Don't be fooled by its evocative nickname: it is perfectly detectable. The misconception that tests do not identify it was propagated by a headline that was corrected.

In Spain, since 13 January, the booster vaccination against covid-19 has been recommended for the general adult population. 78.8 % of those over 50 and 88.9 % of those over 60 have already had it, said the Minister of Health yesterday. If those who are missing have doubts, here we try to solve them.

The terms "endemism" and "seasonality" are increasingly used to refer to the covid-19 pandemic. They are sometimes incorrectly associated with the severity of the disease or with the premature end of the pandemic. What do they mean? Does SARS-CoV-2 fit these definitions? Will it ever do so thanks to vaccines?

The first solid work on the ability of vaccines to stop infection with the omicron variant, which has just been published, reinforces the need for a third dose. Experts recall, however, that the aim of vaccines was never to stop infection, but to prevent severe disease. We summarize what is known so far about it.

The recommendation is to vaccinate children from 5 to 11 years old with the vaccine approved in Europe for this age group, Comirnaty (Pfizer) with one third of the dose used in children over 12 years old. But parents still have doubts. Here we answer the classic ones (safety, risk/benefit) and other more specific ones: allergies, genetic syndromes, high-risk individuals...

"Equity in the distribution of vaccines is not a matter of charity; it benefits all countries," said Tedros Adhanom, director of the WHO. However, his data speak of a very unequal distribution: more than 80 % of the vaccines have gone to G20 countries, while poor countries, mostly African, have received only 0.6 %. Three Spanish experts analyze what went wrong.

The new B.1.1.529 variant, dubbed Omicron, has spread across the globe, with new countries announcing its detection with each passing day. While questions such as whether it is more transmissible are being investigated, the biggest question surrounds its relationship with vaccines - will they cease to be effective, and will this variant escape our immune systems? Several experts answer.

The message that we must continue to protect ourselves with masks, distance, ventilation and hand washing has been repeated since the beginning of vaccination, but in the midst of the pandemic in Europe it is even more important. Several experts warn that the high vaccination coverage in Spain will mitigate the new wave but will not eliminate it: although vaccines prevent serious disease, they are not an insurmountable shield and must be complemented with behavioral measures.

European countries are implementing anti-covid strategies in the unvaccinated population. Austria will make vaccination mandatory after extending its confinement targeting the unvaccinated to the entire population. In Germany, the unimmunized have restricted access to restaurants and hotels, and must show a negative test on public transport. Slovakia has also imposed restrictions on those who have chosen not to be vaccinated. Sweden will introduce a covid passport at events of more than 100 people. What is the effect of these policies?

The United States has already approved the vaccination of children aged 5-11 years against covid-19. In Europe, the European Medicines Agency (EMA) will decide in the coming weeks on the use of the Comirnaty vaccine in this population. Here is what several Spanish paediatricians think about it.