The World Health Organization (WHO) estimates that healthy adults do not require an additional dose of Covid vaccines, beyond primary vaccination and a first booster, as the health benefits are minimal .

For this group of people under 60 said to be at medium risk – to which are also added children and adolescents with comorbidities from 6 months to 17 years – there is no risk in receiving additional injections but “returns to terms of health are low,” WHO vaccine experts said. WHO’s Strategic Advisory Group of Experts on Immunization (SAGE) has released updated recommendations after its meeting this week in Geneva. The new SAGE recommendations reflect the impact of Omicron and the high level of immunity now achieved in the global population due to infections and through vaccination, the WHO said.

SAGE has proposed three new priority categories for Covid vaccination based on the risk of developing a severe form of the disease or death: high, medium and low.

On the other hand, older people, other adults with comorbidities, all immunocompromised people, pregnant women and front-line health workers are advised for more vaccination at a booster dose after the initial regimen of vaccination and a first booster. SAGE recommends an interval of 6 to 12 months between boosters depending on morbidity.

On the other hand, the evidence “lacks consistency” with regard to the impact of anti-Covid vaccines on the long Covid, which sees the initial disease develop into often very disabling symptoms such as extreme fatigue or an inability to concentrate. Nearly 13.3 billion doses of Covid vaccine have been administered worldwide.

The WHO is looking for new Covid vaccines that cover a wide range of variants, have a longer lasting effect and show better performance against infection and transmission. The organization is also investigating new methods of administering nasal, oral or dermal serums.

Discussing two nasally administered vaccines, including one used in China, SAGE Executive Secretary Joachim Hombach said: “We know they are immunogenic…but what we really need is data that actually study the impact on transmission — because it could indeed make a big difference.”