US officials on Wednesday formally announced plans to offer COVID-19 vaccine booster shots to Americans—and the plans are already under fire from experts at the World Health Organization.

US officials are recommending that all Americans vaccinated with two doses of an mRNA vaccine (either the Moderna or Pfizer/BioNTech vaccine) get a third booster dose of the same vaccine eight months after receiving their second dose. As such, boosters will be rolled out based on the order in which people were initially offered vaccines, i.e., with frontline health workers, nursing home residents, and other seniors at the front of the line.

US officials are prepared to begin offering booster shots the week of September 20. However, the timing of the boosters is pending authorization from the Food and Drug Administration and the recommendation of the Advisory Committee on Immunization Practices, an independent committee of experts that advises the Centers for Disease Control and Prevention.

Like the initial doses, booster doses will be free to all Americans, with no identification or health insurance required. The federal government will dole out enough doses for every American to get a booster, which will be offered at roughly 80,000 administration sites nationwide, including local pharmacies.

So far, nearly 200 million Americans have received at least one dose of a vaccine, and nearly 170 million are fully vaccinated. Included in those figures are the nearly 14 million Americans who have received the one-shot Johnson & Johnson vaccine.

Officials expect that those who have received the Johnson & Johnson vaccine will also need a booster, but they are awaiting further data—expected in the coming weeks—before announcing booster plans for those individuals.

Criticism

The Biden administration’s decision to offer boosters was revealed to the press in advance and reported late Monday. In a White House press briefing Wednesday morning, officials outlined their plan for the booster rollout and the thinking and data behind it. Their arguments for third doses were carefully crafted to withstand criticism, which is already coming.

Just hours earlier on Wednesday, the World Health Organization held its own press briefing. Its experts minced no words on why they think the booster rollout is a bad idea.

“The reality is right now, today, if we think about this in terms of an analogy, we’re planning to hand out extra life jackets to people who already have life jackets while we’re leaving other people to drown without a single life jacket. That’s the reality,” Dr. Mike Ryan, executive director of the WHO’s Health Emergencies Programme, said at the briefing. “The science is not certain on [boosters],” he added. “There are clearly more data to collect. But the fundamental, ethical reality is [that] we’re handing out second life jackets while leaving millions and millions of people without anything to protect them.”

The WHO’s sharp criticism of the US plan is no surprise. Earlier this month, the United Nations agency called for a moratorium on booster shots until at least the end of September, which would provide more time to try to vaccinate at least 10 percent of every country worldwide. In making the announcement, WHO Director-General Dr. Tedros Adhanom Ghebreyesus noted that high-income countries had administered 100 doses per 100 people, while low-income countries had only administered 1.5 doses per 100 people due to inequitable access to supplies.

But the argument for equal distribution of vaccines worldwide isn’t merely a moral one; it’s also in the best interest of public health globally. While the pandemic coronavirus is able to freely spread among unvaccinated people anywhere, it will have new opportunities in each infected person to mutate and generate more variants.

Currently, US officials are focused on the delta variant, which was first identified in India and is more than twice as contagious as the original strain of the pandemic coronavirus, SARS-CoV-2. Delta can also escape some immune system defenses, knocking back the efficacy of vaccines. And there is also some data to suggest that it causes more severe disease in infected people.

Variant concerns

Still, delta may not be the worst variant we encounter. There are plenty of opportunities for new SARS-CoV-2 variants to emerge. Health experts are particularly concerned about so-called “escape” variants that can evade all immune responses, rendering our current generation of vaccines ineffective. The CDC has a special designation for such a variant, called “variant of high consequence” or VOHC. So far, no SARS-CoV-2 VOHCs have been identified. (Delta is considered a VOC, or variant of concern.)

“We’re talking about everyone in high-income countries getting a booster,” WHO Chief Scientist Dr. Soumya Swaminathan said. “This is an impossible situation, and I’m afraid that this will only lead to more variants, more escape variants, and perhaps we are heading into more dire situations.”

WHO Senior Advisor Dr. Bruce Aylward echoed the point. “What makes most sense is [to] get at least two doses into the unvaccinated before we get more doses into the well vaccinated.” Right now, vaccine supply is a “zero-sum game,” he said.

In their defense of the booster rollout, US officials noted that the country has already donated more doses than any other country in the world.

“We have already shipped more than 115 million vaccine doses to 80 different countries—more vaccine doses donated than all the other countries in the world combined,” Jeff Zients, White House COVID-19 Response Coordinator, said in the press briefing today, responding to the criticism lobbed by WHO experts. Zients added that the US has also started shipping the half-billion Pfizer vaccine doses that it pledged to purchase and donate to 100 low- and lower-middle-income countries.

Surgeon General Vivek Murthy continued, arguing against the idea of a zero-sum game. “I do not accept the idea that we have to choose between America and the world. We clearly see our responsibility to both… We’ve got to do everything we can to protect people here at home while recognizing that clamping down the [pandemic] across the world and getting people vaccinated is going to be key to preventing the rise of future variants. We know that. We see that clearly. And we believe we have to work on both fronts, as we have been.”

The US officials also used the briefing to explain the scientific data they relied upon to make the call for boosters. Experts at the WHO repeatedly noted in their criticism that the data on the need for boosters is not yet certain—and the US officials didn’t necessarily dispute that.

Calling the shots

The decision to roll out boosters at the eight-month mark for Americans was based on the trajectory of trends and clinical judgment rather than firm evidence that vaccines are failing. In fact, CDC Director Rochelle Walensky and top infectious disease expert Anthony Fauci noted that, so far, vaccines are continuing to offer relatively high levels of protection against severe disease, hospitalization, and death.

But as expected, antibody levels against SARS-CoV-2 are declining in vaccinated people. Though antibodies are not a perfect proxy for overall protection (other, cell-based immune responses also offer protection), antibodies are generally linked to overall protection levels, Dr. Fauci noted in a slide presentation. Moreover, fresh data suggests that protection against asymptomatic and symptomatic infections is declining along with antibodies. And that decline is independent of the fact that vaccines are also less effective against the delta variant compared with previous variants. On top of the worrying trends, data from Pfizer/BioNTech and Modern shows that a third vaccine dose can increase antibody levels more than tenfold.

Together, the officials anticipate that the vaccines will approach ineffectiveness and made the call to offer boosters before that occurs.

“It has been such [an] almost reproducible phenomenon with COVID-19: If you wait for something bad to happen before you respond to it… you’re considerably behind,” Fauci said. “If you look at the indications that we’ve had… you don’t want to find yourself behind, playing catch-up. Better stay ahead of it than chasing after it.”

As for why the officials chose the eight-month mark for boosters, Murthy noted it was merely a judgment call. “There’s nothing magical about this [eight-month] number,” he said. “Could it have been one week earlier, one week later? This is where judgment comes in, and it’s why we’ve put so much time and thought into this decision.”

But for now, Murthy tried to reassure Americans that current vaccine protection remains strong. “What we have said before—which is still true today—is we do not believe that the general population needs booster shots today,” he said. “That was true yesterday. It was true five days ago. It was true a few weeks ago. We are announcing a plan for the future.”

https://arstechnica.com/?p=1788293