WHO gives green light to wider use of Covid vaccine boosters

The World Health Organization has recommended wider use of Covid-19 vaccine boosters, updating its previous guidance when it backed the use of a third shot only in very limited circumstances.

The Strategic Advisory Group of Experts on Immunisation, an independent panel of experts, advised expanding booster programmes alongside the administration of primary doses, with the priority on vulnerable people, the WHO said on Friday.

The new recommendations mark a shift in the WHO’s supply outlook after severe constraints last year that contributed to huge disparities in the rollout of vaccines around the world. Vaccine shortages plagued many countries during much of 2021, prompting the WHO to call for a moratorium on boosters to aid the global uptake of jabs.

According to the new guidelines, countries with moderate-to-high coverage of inoculation in priority groups, such as older people and healthcare workers, should first focus on giving the booster to protect those groups against coronavirus before offering it to others.

Where primary vaccination coverage is low, authorities should focus on achieving high coverage with two shots.

Kate O’Brien, the WHO’s head of vaccines, told reporters the health body saw a “very positive outlook for supply” for 2022. However, she cautioned that this was predicated on dose sharing continuing and manufacturers continuing to honour deals brokered under Covax, the WHO-backed scheme to give people in poor countries equitable access to vaccines.

O’Brien said unequal distribution could continue to complicate global access to vaccines, rather than upstream supply. “This does not mean giving boosters as a priority in all ages,” she said, clarifying the guidance.

About 86 countries continue to have vaccine coverage rates below 40 per cent, a target the WHO had set for 2021. The health body is now targeting 70 per cent coverage in every country globally by mid-2022.

The panel recommended extending the use of the BioNTech/Pfizer shot to children as young as five with a reduced, 10-microgram dose.

Boosters of that jab should be administered four to six months after primary vaccination, and first be given to priority groups.

Alejandro Cravioto, chair of the panel, told reporters a “significant amount of new evidence” had informed the policy update but it was still “grounded” in supporting equitable access, which health authorities have repeatedly said will be key to ending the acute phase of the pandemic.

The spread of the highly transmissible Omicron coronavirus variant has pushed countries to accelerate their booster programmes in their attempts to slow its infection rate. Existing vaccines offer good protection against severe outcomes, though efficacy against infection wanes relatively quickly compared with other variants, even with boosters.

The WHO distinguishes between third shots, which are used to complete vaccination schedules in those who are immunocompromised or particularly vulnerable, and boosters, which are instead used on the general population.