WHO Greenlights COVID Boosters for ‘High-Risk’ Groups but Warns that Blanket Campaigns Could Harm Global Pandemic Response
Hard-hit by Omicron, South Africa has launched a mass COVID vaccination booster campaign, as well as a drive to vaccinate adolescents age 12-17. WHO continues to recommend against both moves.

WHO has issued new advice to countries supporting booster campaigns for “high risk groups” but still opposing “blanket” campaigns – or vaccines for children and adolescents under the age of 18.

The latter, top WHO officials contend, could divert too many vaccines from low-and-middle member states that have low vaccination coverage rates – leading to a boomerang of new variants that also prolong the pandemic.

The WHO advice is being widely ignored, however, as 120 countries worldwide are already vaccinating boostering adult populations in order to ward off yet a new wave of the SARS-CoV2 virus, increasingly driven by the Omicron variant.  Among those are South Africa, at Omicron’s epicenter, which earlier this month began offering boosters to anyone already jabbed with two Pfizer shots – as well as second vaccines to teens aged 12-17. On Wednesday, however, South African health officials said they were seeing a drop-off in soaring infection rates – while fewer cases were ending up hospitalised than would have been the case for the previous Delta wave.  

In terms of boosters guidance, the new recommendations by WHO’s SAGE experts paint a very broad brush – recommending that countries  introduce booster campaigns that are “evidence driven and targeted to the population groups at highest risk of serious disease and those necessary to protect the health system”.

While cautious, and still seemingly out of step with what is happening on the ground, the new WHO advice that countries might consider boosters for “high-risk” groups – walks back from Director General Dr Tedros Adhanom Ghebreyesus’ previous calls for a booster “moratorium” – excepting immunocompromised people, such as cancer patients. 

WHO Director General Dr Tedros Adhanom Ghebreyesus

The SAGE statement avoids any specific recommendations about what ‘high-risk’ groups might actually be the best booster candidates – leaving countries to decide if they want to prioritise people at occupational risk, such as health workers, older people and/or those with chronic diseases.  

Speaking at a Wednesday’s pre-holiday press briefing, Dr Tedros conceded that boosters could indeed be selectively administered to unspecified “high risk” groups without jeapordizing global supplies – but stressed that broad-based booster campaigns should still be avoided.  

“Our projections show that supplies should be sufficient to vaccinate the entire global adult population and to give boosters to high risk populations by the first quarter of 2022,” he said. 

“However, only later in 2022 will supply be sufficient for extensive use of boosters in all adults. So I call once again on countries and manufacturers to prioritize COVAX and work together to support those who are furthest behind.”  

He failed to elaborate.

No details on WHO vaccine supply projections

Despite repeated requests by Health Policy Watch, WHO has not provided further details of its vaccine supply and demand projections under different booster scenarios.

Last week, however, a senior WHO official predicted that low-income countries could come up 3 billion doses short in the first quarter of 2022 if boosters were “aggressively” administered in the some 120 high- and middle-income countries that have begun offering third jabs – a statement later challenged by the pharma industry.

The WHO projection assumed that the high-and middle income countries that have launched booster campaigns would reach 90% coverage with primary vaccines and boosters by March 2022 – when in fact coverage in most countries has failed to reach even 70% for just the primary vaccine series.

Financial Times mapping of WHO claims of 3 billion vaccine dose shortfall – based on 90% vaccine coverage in all high/upper middle income countries.

Acknowledges waning immunity for the first time 

Soumya Swaminathan, WHO Chief Scientist

The new SAGE advice also acknowledges, for the first time, evidence of waning immunity against SARS-CoV2 over time, conceding that there is a :”decline in vaccine effectiveness against SARS-CoV2 infection and COVID-19 with time since vaccination, and more significant decline in older adults.

That evidence includes an 8-15% decline in protection against serious COVID disease among all age groups, and a 32% decline in protection against symptomatic disease for people over the age of 50 – from the leading mRNA and AstraZeneca vaccines, according to the WHO expert review.  

The policy statement also acknowledges that the erosion of vaccine-derived immunity might be even more pronounced in the case of the Omicron variant. 

Vacccine efficacy against Omicron – still many uknowns

Speaking at the press briefing, WHO Chief Scientist stressed that there remain many unknowns about vaccine efficacy against the new variant – most knowledge is based upon laboratory assays – not real-life experience.

“Almost all of the lab assays have shown a considerable reduction of neutralization [antibody capacity] against the Omicron variant. But there should still be a good amount of T-Cell immunity,” she added, noting that immunity is grounded in multiple pathways.”

“For now we believe that boosters may be needed for people who have weaker immune systems, older individuals more vulnerable people,” Swaminathan said in a video released shortly before the presser.  

The SAGE experts also point out that administration of booster doses to the more vulnerable might be preferable to the administration of primary doses to low-risk groups – particularly children and adolescents – which WHO still has not recommended be vaccinated at all: 

“Modeling shows that greater reductions in mortality may be achieved by administering booster doses to high-risk populations than using those same doses for primary immunization of lower risk populations. 

“As supply increases and vaccination is expanded to lower priority age groups, trade-offs may need to be considered as to prioritizing booster vaccination to high-risk populations over expanding primary immunization coverage to younger populations. WHO is currently not recommending the general vaccination of children and adolescents as the burden of severe disease in these age groups is low and high coverage has not yet been achieved in all countries among those groups who are at highest risk of severe disease,” the SAGE group concluded. 

Global equity and supply 

COVAX supply forecasts – from a vaccine facility for the world, it has become a vaccine supplier largely to the world’s 93 lowest-income countries, including large quantities of donated doses – with huge lags in delivery dates.

A key consideration in the booster recommendations continues to be fears that global vaccine supplies could be diverted from the global COVAX vaccine facility and African Union efforts, which are trying to ensure that vaccine coverage reaches the 40% target in the more than 90 low-income WHO member states that have struggled to roll out vaccines altogether.  

“Only half of WHO member states have been able to reach the target of vaccinating 40% of their populations by the end of the year, because of the distortions in the global supply,” said Dr Tedros in his media comments, adding that: 

“Enough vaccines were administered globally this year that the 40% target could have been reached in every country by September. If those vaccines had been distributed equitably, through COVAX  and others. 

“We are encouraged that supply is improving. Today, COVAX shipped its 800 millionth vaccine dose –  half of those have been shipped in the past three months. 

For national health systems, “the focus of immunization must remain on decreasing deaths and severe disease.” 

Blanket booster programmes likely to prolong the pandemic, rather than ending it

But countries have another good reason to be selective about booster jabs, Tedros added, saying that: “Blanket booster programs are likely to prolong the pandemic rather than ending it.

“Diverting supply to countries that already have high levels of vaccination coverage, gives the virus the opportunity to spread and mutate,” he added. 

 “It’s important to remember that the vast majority of hospitalizations and this are in unvaccinated people, not unboosted. 

“The global priority must be to support all countries to reach the 40% target as quickly as possible. And the 70% target by the middle of this next year [2022]. No country can lose its way out of the pandemic.”

Use N-95 Masks – new  WHO advice to health workers in light of Omicron concerns 

A USA FDA certified brand of N95 particulate respirator mask for health workers; the highest quality ones are rated by national authorities but cheaper imitations from Asia have also flooded markets since the beginning of the COVID pandemic.

In a parallel announcement, WHO also said it is recommending that health workers routinely use more protective N-95 or FFP-2 respirator masks with a rated ability to filter out most fine particles – including virus-bearing aerosols. 

The masks, along with gowns, gloves and eye protection, should be worn by any health care workers entering any room where suspected or confirmed COVID patients might be lodged.  

The recommendation was accompanied by a call from Dr Tedros to mask manufacturers to step up their production of the masks saying: 

“We are painfully aware that many health workers around the world are unable to access respirators. We therefore ask manufacturers and countries to scale up the production procurement and distribution,” he said. 

In light of respirator [mask] shortages and burgeoning mask waste disposal issues, he noted that WHO also has issued an initial summary of evidence around methods for reprocessing the higher-quality N-95 respirator masks or their equivalent  – including UV light exposure, heat exposure, sterilization, and chemical treatment, e.g. with hydrogen peroxide vapours.

Omicron is clearly more transmissible, but is it as severe as Delta? 

Maria Van Kerhkove, COVID-19 Technical Lead

The recommendations come as certainty mounts that the  Omicron variant of SARS-CoV2  is more transmissible than its Alpa, Beta, Gamma or Delta predecessors – although it’s too soon to conclude if the variant is less or as severe as Delta, which swept the world in spring 2021.

“What we are learning about Omicron is certainly that we have this increased transmission, but the information on severity is still uncertain,” said Maria Van Kerkhove, WHO COVID technical lead on the Health Emergencies team. 

“We don’t have that complete picture yet it is too early to conclude whether or not Omicron is less severe than Delta or is as severe. 

“Now we do have some data suggesting that rates of hospitalization are lower, that people who are hospitalized don’t need as much oxygen or invasive ventilation. 

“But again, we have not seen this variant circulate for long enough in populations around the world, certainly in vulnerable populations. We did learn some information this week that older people with Omicron tend to have more severe disease. That’s unsurprising. 

“We know people have died from Omicron… but the data is a little bit messy, it’s being generated right now,” she added, concluding with a plea that groups celebrating the Christmas and New Years holidays curb their social contacts in order to cut down on the variants’ rapid advance across the globe.  

“We have been asking people to be cautious. We’ve been asking governments to be caution and to really think, especially as these holidays are coming up, and there are very difficult decisions that need to be made in terms of making sure that we keep ourselves safe.”

Image Credits: Gauteng Department of Health, The Financial Times , Airfinity, ACS Material/BYD Brand .

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