The World Health Organization (WHO) said Tuesday it is no longer suggesting additional Covid-19 extra vaccine doses for regular, medium-risk adults as the benefit was marginal.
For those people who have received their prior vaccination course and one booster dose, there is no threat of having additional jabs but the returns are slight, the WHO’s vaccine experts said.
The UN health agency’s Strategic Advisory Group of Experts on Immunisation (SAGE) issued updated suggestions after its regular biannual meeting.
SAGE’s new recommendation reflects the influence of the dominant Omicron variant of the virus and the high-level immunity now conducted in the population through infection and vaccination, the WHO said.
SAGE came up with three further, simplified primacy categories for Covid vaccination: high, medium, and low, based on the threat of severe disease or death. SAGE recommended further booster shots after the first one only for people at the highest risk of generating severe Covid-19 disease.
They include older adults; younger adults with comorbidities such as diabetes, people with immunocompromising conditions like HIV, pregnant women, and frontline health workers.
The medium primacy group includes healthy adults, usually under 60, and children and adolescents with comorbidities. SAGE recommends a primary series and a first booster dose.
When it comes to the medium-risk group, additional booster doses are no longer recommended. The vaccine is safe and it’s efficient against serious disease and death, but for this risk group, while there was no harm in having another shot, the benefit of these additional boosters is actually quite marginal.”
SAGE chair Hanna Nohynek
The low-priority group includes healthy children aged six months to 17 years. While primary and booster doses are secure and sufficient for this group, regarding the low hurdle of Covid disease, SAGE said countries’ vaccination judgments should be based “on contextual factors” such as health program preferences and cost-effectiveness.
As for the impact of Covid-19 vaccines on Long Covid, or post-infection conditions, “the evidence on the extent of their impact is inconsistent”, said SAGE. Nearly 13.3 billion Covid vaccine doses have been administered around the world.
WHO vaccines chief Kate O’Brien said that versus Omicron, the current vaccines deliver very good immunity against tough disease, but “honestly they don’t last very long for the performance that they do have against mild disease or infection”.
WHO is scrutinizing new Covid vaccines that protect a wide scope of variants, have longer durability, and have more useful performance against infection and transmission. It is also pursuing vaccines that are moving on from injection methods and ultra cold chain storage, O’Brien said, citing nasal, oral, and skin patch vaccine methods.
We know that they are immunogenic… but what we really need is data that actually studies the impact on transmission — because that could indeed make a major difference.”
Joachim Hombach-SAGE executive secretary
