WHO recommends second COVID-19 booster vaccine for at-risk groups

The World Health Organization (WHO) this Thursday recommended for the first time the use of a second vaccine revaccination against COVID-19 in groups most likely to develop a severe clinical picture, after observing a decrease in immunity against the omicron variant.

These groups include all older people (each country should establish at what age according to national criteria), immunocompromised people, all adults with chronic diseases, and pregnant and to medical staff.

The ideal interval between the first and second revaccination should be four to six months, the same period during which the effectiveness of COVID-19 vaccines begins to decline. If this period is exceeded, a person at risk should be vaccinated as soon as possible.

HOW MUCH AGAIN WILL WE NEED TO BE VACATIONATED?

Scientific studies have shown that because pandemic dominated omicron variantimmunity offered by vaccines or created by a previous infection is reduced “not very much, but enough in case of severe cases”.

“We are making this recommendation based on the information we have now, but it is not a forecast for the future. We are not saying that from now on it will be necessary to vaccinate every four or six months, we will see how pandemic”, one of the experts of the group, which advises WHO in this question Joachim Hombach.

However, a document published by the group WHO notes that “additional doses are likely to be required within four to twelve months after the second revaccination, especially among people vulnerable to severe disease or at risk of death.”

Hombach also clarified that the recommendation for a second boost (in most cases this will be the fourth dose) is not directed at healthy adults who are at very low risk of getting sick. severe covid.

In this regard, the president of the group, Mexican scientist Alejandro Cravioto, mentioned recent studies showing that half of the people who were infected with omicron were unaware of it because they had no symptoms, which could provide new insights into the functioning of natural immunity against it. option.

“Vaccinating everyone without knowing if it will affect transmission can be a waste of vaccines and time because it would require a lot of staff,” he explained.

Immunization Expert Group WHO held an extraordinary meeting to review the evolution of the pandemic in terms of vaccination, and also concluded that countries could consider introducing vaccine against COVID-19 together with flu shot.

NEW VACCINES

As part of the development of several vaccine stop the spread of covid, pharmaceutical modern She was the first to produce a bivalent vaccine based on the original coronavirus and its omicron variantand whose use was originally approved United Kingdom.

In this regard, WHO announced today that it recommends a second dose of this vaccine It is administered eight weeks after the first, as it has been observed that the efficacy is higher with this interval and that the risk of myocarditis is reduced.

He added that all of this must be judged against the urgency that the person at risk of protection might face.

This vaccine can also be used, according to experts, as the first or second revaccination recommended from today.

The organization also reaffirmed its position that people can receive doses vaccine different manufacturers and different technologies.

On the other hand, a group of experts from WHO approved the use vaccine French-made Valneva in persons aged 18 to 50 years, which must be administered in two doses intramuscularly.

Between the first and second dose of the initial treatment regimen vaccination must elapse at least 28 days, although when administered as a booster dose, four to six months must elapse (like the rest vaccine).

(EFE)