TORONTO -- The U.S. is preparing to embark on an ambitious and controversial program — offering a third dose of the Pfizer or Moderna vaccine starting Sept. 20 in a bid to further fight COVID-19 infections, despite international criticism highlighting that many countries are still fighting to acquire first doses.

U.S. health officials announced on Wednesday that third shots would be available in September to Americans who had received their second dose of the vaccine at least eight months earlier, citing waning protection and the rise of the Delta variant as contributing factors.

It’s a plan that has received criticism from numerous experts.

“If you ask the question in August of 2021, do we need booster vaccines for the general population? The answer is no, we don’t,” Dr. Isaac Bogoch, an infectious disease specialist, told CTVNews.ca in a phone interview. “And when I say that, I'm saying [that] based on the available data.

“I think to make a policy decision like that, you're going to need much more robust data.”

Health-care providers and long-term care residents in the U.S. will be among the first to be eligible for the booster shots due to the eight month rule, but the booster shots are to be available to all Americans, not just those at high risk of COVID-19.

“Recent data makes clear that protection against mild and moderate disease […] decreases over time,” Vivek Murthy, the U.S. Surgeon General, said of the decision.

Officials say the Delta variant is swamping hospitals with severely ill patients. And there are signs from Israel showing immunity drops eight months after the shots. Israel is now giving out booster shots to older adults and those with weak immune systems after seeing a sharp rise in infections. Germany and France have also decided to offer booster shots to these populations.

But some scientists have questioned recent Israel data, saying it fails to provide a full picture. 

“When you compare, for example, vaccinated versus unvaccinated people in the same age group, it's still very clear that the vaccines are extremely effective,” Bogoch said.

Among the scientists saying the call for booster shots is too early is the World Health Organization (WHO), which stated Wednesday that they see no medical need for booster shots at this time.

“The outcomes that we are really concerned about, which is severe disease hospitalization and death, those are clearly being prevented by the vaccines,” Dr. Soumya Swaminathan, WHO’s chief scientist, said Tuesday in a press conference.

There is little evidence that boosters are necessary to protect the general population currently. Studies have only really shown that a third dose benefits those with weaker immune systems.

“So in those people, I think, the booster is necessary. But for the overall population, the jury is still out,” said Dr. Deepali Kumar, an infectious disease expert with the University Health Network. 

This is one reason that boosters for otherwise healthy Canadians aren't on the table at this point.

“In Canada, many people are still relatively newly vaccinated, and we know that the immune response remains very strong in the short term, and we have the data to show that it's dramatically reducing severe disease and hospitalization in Ontario and in Canada,” Dr. Fahad Razak, a clinician scientist at St. Michael’s Hospital, told CTV News Channel on Wednesday.

Bogoch said it’s important to look at the question from two angles.

“Is there a medical reason to get a booster vaccine? Do you actually need booster vaccines now at a population level?” he said. “And is it ethical to give third doses of vaccinations when billions, truly billions of people in low-income countries and middle-income countries haven't even received a first dose of a vaccine? So from a medical and public health standpoint, when we're talking at a population level, no, there doesn't appear to be any reason.”

VACCINE INEQUITY

One of the big concerns with the U.S. plan is that 98 per cent of those living in poorer nations have yet to receive even a single dose of the vaccine. According to the Lancet, by August 9, of the 4.46 billion doses that had been administered globally, only 12.6 million were in low-income countries.

The Infectious Diseases Society of America said in a statement Wednesday that there needs to be a “thorough and transparent evaluation of the evidence” before Americans receive booster shots.

“Making supplemental doses available to individuals in the U.S. must be done in concert with maximizing efforts to provide COVID-19 vaccination to low- and middle-income countries,” the statement says. “We cannot successfully end this pandemic without global vaccine equity.”

World health officials are calling third shots for the wealthy shameful.

“Vaccine injustice is a shame on all humanity,” WHO Director-General Tedros Adhanom Ghebreyesus said in Wednesday’s press conference. “And if we don’t tackle it together, we will prolong the acute stage of this pandemic for years, when it could be over in a matter of months.”

On August 4, WHO called for a moratorium on booster shots in high-income countries until at least the end of September, in order to allow other countries a chance to protect their citizens with those crucial first and second doses.

"We're planning to hand extra life jackets to people who already have life jackets, while we're leaving other people to drown without a single life jacket,” Dr. Mike Ryan, executive director of the WHO Health Emergencies Programme, said in press conference Wednesday. “That's the reality.”

Some experts say that while there is evidence that booster shots may be helpful in the future, getting the rest of the planet vaccinated is more important than wealthy nations stocking up on extra shots.

Jesse L. Goodman, a professor of medicine at Georgetown University, said in an online Q&A with SciLine on Wednesday that while we’re seeing protection against overall infections waning some, we aren’t seeing this have an effect on hospitalization and deaths.

“So far vaccine protection against those more severe manifestations is holding up well,” he stated.

To address more severe outcomes, “we really need to focus first on vaccinating the unvaccinated, both here in the U.S. and globally,” he added.

“Booster shots may help protect some people, particularly our most vulnerable individuals, but are far less likely to impact the overall curve of the pandemic.”

Bogoch said it’s highly likely that we will require booster shots at some point, but added that vaccine manufacturers are already looking at creating vaccines targeted at current variants, and that future booster shots could come from this work as opposed to the existing vaccines.

“I think it's pretty clear that we'll probably need a booster vaccine at some point,” he said. “That should be on our radar.”

However, many experts believe that other developed nations, including Canada, will eventually follow the U.S. in offering third doses soon to citizens, a vaccine nationalism that they agree may not be the best medicine.