The United States Food and Drug Administration (US FDA) on Friday gave its greenlight to the mass rollout of both Pfizer and Moderna COVID booster shots to all adults over the age of 18, from six months after a person’s second vaccine dose.  J&J vaccine boosters would be authorized after just two months of the single jab vaccine.

The US Centers for Disease Control was due to meet later Friday on a policy recommendation to expand booster shot eligibility to all American adults accordingly – CDC Director Rochelle Walensky was expected to sign off on the recommendation immediately.

“This is a very encouraging step to further protect Americans, especially as we enter the winter months,” said White House press secretary Jan Psaki in a press briefing Friday afternoon.

Boosters of Moderna and Pfizer’s mRNA vaccines have been repeatedly decried by the World Health Organization as pumping global vaccine inequities while lacking an adequate evidence base.

“No more boosters should be administered except to immunocompromised people,” said WHO’s Director General Dr Tedros Adhanom Ghebreyesus earlier this month. “Most countries with high vaccine coverage continue to ignore our call for a global moratorium on boosters at the expense of health workers and vulnerable groups in low-income countries who are still waiting for the first dose.”

The decision was not without its naysayers – some critics pointed out that the critical FDA decision was made largely on the basis of industry data of its clinical trials, but without reference to the FDA’s expert Vaccines and Related Biological Products Advisory Committee, VRBPAC, which usually weighs in first.

The FDA decision was being cheered, however, by many US experts as a correct response to mounting medical evidence about waning immunity after the first two jabs, as well as a nimble way of warding off another winter COVID wave.

“I’ve said since January that Pfizer/Moderna are three dose vaccines,” said Peter Hotez, a vaccine expert at Texas Children’s Hospital and popular media commentator.

Since the beginning I've said the mRNA vaccines = 3 dose vaccines. Reason: We spaced first two doses close together to rapidly immunize vulnerable populations, but that had the downside of acting as a primary immunization, necessitating a third dose. The good news… pic.twitter.com/yuAiWP1JXN

— Prof Peter Hotez MD PhD (@PeterHotez) November 19, 2021

Signal to Europe

The US moves will also surely be seen as a signal to European policymakers – facing sharply rising case rates accompanied in some countries, such as The Netherlands, by partial lockdowns.

In Europe, boosters have not been widely administered yet beyond immuno-comprised individuals and people over the age of 65.  The United Kingdom has been the boldest so far – gradually scaling down eligibility ages.  On Monday, UK officials announced that the age limit for booster eligibility would be lowered once again to people aged 40-49 who received their second shot more than six months ago.

Trying to keep objective.
But looking at the numbers around boosters, my main concern is that the results are being absurdly undersold.
Most people are sick of COVID, sick of being told what to do, and are thinking of boosters are a nice-to-have.
They are transformative.
(1/4) pic.twitter.com/coSDo7YtpD

— Paul Mainwood (@PaulMainwood) November 18, 2021

Boosters sharply opposed by WHO – but appeals likely to be ignored

The booster shot trend has been sharply opposed by the World Health Organization as siphoning off vaccines that are badly needed in low- and middle-income countries to merely administer a first dose.

WHO has repeatedly called for a  moratorium on booster shots until the end of the year for everyone except immunocompromised people – so as to reach a 40% vaccine coverage goal in under-vaccinated countries – including most of Africa.

WHO scientists have contended that even if infection rates are rising right now in the northern hemisphere, as Europe and North America head into winter, people with two jabs remain good immunity against serious disease and hospitalization – which is a more central aim of vaccination that preventing simple infections.

However, WHO’s appeal may be increasingly ignored by countries anxious to head off another winter surge in case rates – in countries that were the epicenter of the COVID storm at its outset in 2020, riding another major wave last winter.

The dilemmas become particularly acute when those surges are also leading to more hospitalization – straining health care services.

Israel’s booster drive cited by US expert Anthony Fauci as example

 Israel’s experience has been widely cited in the United states, which has seen a steady rise in new infections over the past month. In Israel, COVID infection rates soared to the highest in the world in August – pushing hospitals to their limits.

At that point a massive booster campaign was implemented, which officials there now admit was a “calculated gamble”.  Along with stricter social distancing measures in bars and restaurants, the campaign drove case rates down to one of the lowest in the developed world.

But more significantly, the Israeli campaign drove down the incidence of serious infections and hospitalizations among older people, most at risk, said Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, in an interview with CNN.

Recent data from Israel shows that people age 60 and older who received a booster were less likely to become severely ill than vaccinated people who had not received a booster. Rates of severe disease, however, remained highest among those who weren’t vaccinated at all.  In the biggest Israeli study to date, covering some 728,000 people and published 29 October in The Lancet, the booster was estimated to be 93% effective in preventing hospital admissions, and 81% effective in preventing deaths – in comparison to people who received only two doses.

Tackling vaccine inequities – and uncovering the root causes of serious COVID disease

In terms of the continuing vaccine inequalities between the global north and south, some commentators have argued that vaccine hoarding of excess doses by rich countries may be an even bigger equity bottleneck than booster doses.

Others continue to ponder what are the drivers between the strikingly low case rates in most of SubSaharan Africa – South Africa excepting – and chronically high case rates elsewhere in Latin America, India and the Europe.

While partially due to under-reporting, some researchers have speculated that Africa’s generally lower rates may also be partially explained by immunity acquired from other, prior diseases, including possibly malaria.

That, at least, was the conclusion of researchers with the Uganda-based Malaria Consortium, which recently published a study in The Lancet Microbe, suggesting that people with high prior exposure to malaria also may have less severe forms of COVID-19.

The study, which analysed the results of 597 COVID patients at treatment centers in Uganda, found that 30% of the proportion of people with low previous exposure to malaria had suffered severe or critical COVID, as compared to only 5.4% of poeple with high previous malaria exposure.

“The results suggest that if you’ve had a high previous exposure to malaria, you’re likely to control or manage COVID-19 better,” said Jane Achan, senior research manager at the Malaria Consortium in a blog post.

Regardless of mitigating factors, the fact that vaccine rates in some 80 countries have not yet reached the 40% mark, and remain under 5% in much of Africa, continues to frustrate global health officials that see the inequalities as both an ethical stain as well as a health security risk for the rest of the world – creating more fertile territory for COVID variants to flourish long-term.

The US administration’s response to global vaccine constraints has been firstly donations,  followed by negotiated deals with Pfizer and other manufacturers for vaccine supplies at cost to LMICs, and a call for the rapid expansion of its own domestic vaccine manufacturing capacity – to respond to needs in both the domesitc and global markets. But the donations have so far failed to be delivered; similarly Pfizer’s promised supplies as well as more domestic production will only rev up in 2022.

At home, meanwhile, some states have already moved ahead of the US FDA and CDC, issuing their own recommendations that approved booster shots for adults six months after their first jab.

“Vaccines are the best way to protect ourselves, our loved ones, and everyone around us,” tweeted Michigan’s Lieutenant Governor, Garlin Gilchrist II on Friday.  “Today I got my booster, I encourage Michiganders to get their primary doses- for themeslves and their kids 5 and up – or their boosters when eligible.”

https://twitter.com/LtGovGilchrist/status/1461751602554015762

Image Credits: @LtGoVGilchrist, https://covid19globaltracker.org/.