The World Health Organization (WHO) recommended a second booster vaccine against covid 19 for the most vulnerable groupsthat is, those who are more likely to develop severe disease. They do this after verifying that the immunity against the omicron is waning.
This group includes people that each country considers older according to age criteria, immunocompromised, pregnant women, patients with chronic diseases or healthcare personnel. WHO recommends inoculation between 4 and 6 months after the first booster dose.
How many additional booster doses will there be?
Various studies have shown a decrease in the protection of vaccines against the omicron variant. Originally they were bred against the previous variants and although they are still effective, a loss of immunity “insignificant, but sufficient in the case of severe cases”.
“We make this recommendation based on the information we currently have, but it is not a projection into the future. We are not saying that from now on we will have to be vaccinated every four or six months, we will see how the pandemic evolves ”Joachim Hombach, one of the experts in the group advising the WHO on this issue, told reporters.
The WHO leaves door open for future booster doses beyond the second it currently offers: “Additional doses are likely to be needed within four to twelve months of the second booster, especially in people who are at risk of serious illness or at risk of death.”
They point out, however, that this recommendation does not apply to the healthy adult population, among whom the risk of suffering from severe covid is very low.
On this subject, the president of the group, the Mexican scientist Alejandro Cravioto, underlines that “vaccinating everyone, without knowing if it will have an impact on transmission could be a waste of vaccines and time because it would require a lot of staff,” he explained.
The WHO Expert Group on Immunization held an extraordinary meeting during which it reviewed the evolution of the pandemic from the perspective of immunization and also concluded that countries could consider administering covid-19 vaccines at the same time as the flu vaccine.