Look Who’s Rushing Covid Vaccines Now

The FDA is in a tough spot. The original vaccines, which targeted the Wuhan variant, are much less effective against Omicron and even less so against subvariants that evolved in rapid fire—BA.2, BA.2.12.1, BA.4 and BA.5. Vaccine makers spent this winter and spring testing vaccine configurations for Omicron and future variants. Some variants—including those that never became widespread in the U.S., such as Beta—share many of the same mutations. The trouble is nobody knows how the virus will evolve.

In late June, Pfizer and Moderna presented data to an FDA advisory committee on their experimental boosters, which targeted Omicron both alone and in combination with the Wuhan variant. The BA.4 and BA.5 variants had surged relatively recently, so the vaccine makers hadn’t had time to devise and test shots targeting them.

The FDA advisers found themselves in conflict, and so were the data. Pfizer’s data showed that its Omicron-specific booster generated a stronger antibody response to Omicron than its combination vaccine. Yet Moderna’s combo booster produced a more durable immune response—i.e., antibody levels stayed high longer.

Some advisory members worried that the FDA was moving too fast with too little data. “I think we need a higher standard than what we’ve been given. I think it’s uncomfortably scant,” said

Paul Offit

of the Children’s Hospital of Philadelphia. Members also were wary of recommending new boosters that target the BA.4 and BA.5 variants given the lack of evidence. With the advisory committee at loggerheads, the FDA made the executive decision—as is its prerogative—to direct Moderna and Pfizer to reconfigure their vaccines for the BA.4 and BA.5 variants in combination with the Wuhan variant.

The White House wanted the boosters available in the fall, which didn’t leave the FDA time to wait for more studies. Even so, last week’s decision was hasty. Antibodies wane after a few months, so even if the new shots are initially effective, those who get boosted in September will be susceptible to infection again by Christmas. The FDA surely could have waited for more efficacy data.

Alternatively, it could have limited its authorization to elderly and high-risk patients, for whom the benefits, while uncertain, are more likely to outweigh the potential risks. Yet the agency couldn’t do this without acknowledging the shots carry risks, which it appears loath to do lest it encourage vaccine hesitancy.

Last Wednesday an independent analysis of the Pfizer and Moderna vaccine trials in 2020 was published in the journal Vaccine. It found that serious adverse events like kidney disorders were 36% more common in the Pfizer vaccine than the placebo group, at a rate of one in every 555 patients dosed. A similar discrepancy wasn’t found in the Moderna trial.

This followed a Journal of the American Medical Association study this summer that found veterans who received the Pfizer vaccine were significantly more likely to experience severe health problems, including myocarditis, heart attacks and hemorrhagic stroke, in the 38 weeks after vaccination than those who got the Moderna shot.

Yet the FDA summarily concluded, “based on the totality of the scientific evidence available, that the known and potential benefits” of the Pfizer bivalent booster outweigh its “potential risks” in people 12 or older. In fact, the benefits have yet to be proved, and the FDA didn’t conduct a risk-benefit analysis.

Drugs can cause severe side effects, which sometimes are so rare that they aren’t discovered until after large numbers of people have taken them. When new evidence about risks comes to light, public-health authorities normally revise their guidance to ensure that the benefits outweigh the risks. The U.S. Preventive Services Task Force last fall revised earlier guidance by recommending against older adults taking low-dose aspirin daily to reduce the risk of stroke and heart attack after evidence showed that the risk of internal bleeding from the drug exceeded the benefit.

The FDA’s failure to analyze the new boosters’ potential risks against their potential benefits for different age groups leaves Americans on their own, having to decide whom to trust. Officials have only themselves to blame when vaccine skeptics fill the vacuum of information.