Enlarge / A phlebotomist draws blood meant for antibody testing. (credit: Frederic J. Brown / Getty Images )

We've tended to treat the RNA-based vaccines from Moderna and Pfizer/BioNTech as functionally equivalent. They take an identical approach to producing immunity and have a very similar set of ingredients. Clinical trial data suggested they had very similar efficacy—both in the area of 95 percent.

So it was a bit of a surprise to have a paper released yesterday indicating that the two produce an antibody response that's easy to distinguish, with Moderna inducing antibody levels that were more than double that seen among people who received the Pfizer/BioNTech shot. While it's important not to infer too much from a single study, this one was large enough that the results are likely to be reliable. If so, the results serve as a caution that we might not want to base too many of our expectations on relatively crude measures of antibody levels.

The new study

The work itself was remarkably simple. A Belgian medical center was vaccinating its staff and asked for volunteers willing to give blood samples. Samples were taken both prior to vaccination and six to 10 weeks after, with the levels of antibody specific to the SARS-CoV-2 spike protein tested at both points. About 700 participants received the Moderna vaccine, while roughly 950 took the one from Pfizer/BioNTech.

Enlarge (credit: Mario Tama | Getty Images)

On Monday, the US Food and Drug Administration gave formal, full approval to the Covid-19 vaccine made by the drug companies Pfizer and BioNTech. You might’ve already gotten a dose of it, of course; millions of Americans have, thanks to an “ emergency use authorization ” awarded in December 2020. But the new designation was more than just a formality. “If you’re one of the millions of Americans who said they will not get the shot until it has full and final approval from the FDA, it has now happened,” President Joe Biden said when he announced the approval. And, in the same speech: “If you’re a business leader, a non-profit leader, a state or local leader who has been waiting for full FDA approval to require vaccinations, I call on you now to do that—require it.”

Pretty much right away, a lot of places did. Vaccines are safe, effective, and free, but somewhere around 30 percent of Americans haven’t got their shots. Carrots didn’t work; here come the sticks. And they might be able to crush the fourth wave of the Covid pandemic in the US—if they’re done right.

Like the other vaccines still available under EUA, the Pfizer drug is extraordinarily good at keeping people from getting really sick or dying from Covid. But with more than 100,000 people in the hospital with Covid in the US—the most since January—and with the vast majority of them unvaccinated, it’s clear that alone isn’t enough. States, localities, and businesses have tried inducements like prizes, cash, or lotteries , little tricks designed to corral people into doing what’s good for them. In the language of behavioral economics, that’s called a nudge. But in states with low vaccine uptake, those nudges didn’t change the momentum. So now, it’s time for mandates . If you’re one of the 30 percent or so of Americans who haven’t gotten vaccinated yet, get ready for a good hard shove.

Enlarge / President Joe Biden speaks to a member of the media after delivering remarks in the East Room of the White House with Vice President Kamala Harris, left, in Washington, DC, on Monday, May 17, 2021. Biden plans to send an additional 20 million doses of vaccines abroad by the end of June. (credit: Getty | Bloomberg )

President Joe Biden announced on Monday that the United States will share at least 20 million doses of Pfizer-BioNTech, Moderna, and Johnson & Johnson COVID-19 vaccines with other countries over the next six weeks.

The pledged doses will be in addition to 60 million stockpiled doses of AstraZeneca’s vaccine the administration has previously said it will donate after they’re cleared by the Food and Drug Administration.

The announcement comes amid mounting pressure for the US and other rich nations to share doses with low- and middle-income countries, some of which are struggling with COVID-19 surges amid a dearth of doses. It also comes as the US has a glut of vaccine doses and is now struggling to convince a vaccine-hesitant portion of the population to take the available shots.

Enlarge (credit: Luis Alvarez )

Before the COVID-19 pandemic, it was possible to believe that the US public's skepticism of scientific information had some limits. Once a crisis hit a critical point—when things became a matter of life and death—people would come around, the thinking went.

Obviously, that hasn't been the case. The US public's skepticism toward science is extending toward one of its most important developments: vaccines. The COVID-19 vaccines offer both the prospect of a return to normal life and limits on the risk of dangerous coronavirus variants evolving—but only if enough people are vaccinated. And that "but" is looming larger as states are having to experiment with various inducements to get more people to take the vaccine.

Given this situation, any data that helps us understand why people might be hesitant to get vaccinated could be valuable. Some researchers have now found a hint that trust in science is more complicated than an individual belief. The societal consensus on trust in science matters, too.

Enlarge / If you've been vaccinated, the CDC now says you can skip the mask and spacing. (credit: Luis Alvarez/Getty Images )

As part of an ongoing press conference, the Centers for Disease Control responded to recent data on the effectiveness of vaccines and updated its guidance on mask use and physical distancing. Under the new guidance, anybody who is fully vaccinated (meaning two weeks after the final dose of their vaccine) can now skip mask use and social distancing both indoors and outdoors.

"Anyone who is fully vaccinated can participate in indoor and outdoor activities—large or small—without wearing a mask or physical distancing," said CDC Director Rochelle Walensky. There are some limits to the locations where this applies, like hospitals, airplane, and other forms of public transport. But, for the most part, people who have been vaccinated can return to normal activities.

The press conference is ongoing, and we'll update this story once it's over.

Enlarge / With new data, we're able to expand vaccinations to ever-younger populations. (credit: Roberto Jimenez Mejias / Getty Images )

On Wednesday, the CDC's Advisory Committee on Immunization Practices recommended that the CDC approve the use of the Pfizer/BioNTech COVID-19 vaccine for the 12- to 15-year age group. The decision comes two days after the FDA granted an emergency use authorization for the same age group and will help the US further limit the pool of people who can spread infections or foster the evolution of new viral variants. Formal CDC approval could come quickly, given recent history.

Given the FDA's earlier decision, the move might seem anticlimactic. But having the FDA and CDC officially on the same page is reassuring, and several state-run vaccination programs are awaiting the CDC's OK before expanding into that age group. Private providers and insurance companies were also varied in their response to the FDA's decision and were waiting for the CDC.

The data that supported the approval was pretty decisive, as a small Phase III clinical trial of 2,260 adolescents saw 16 cases of COVID-19, with every single one occurring in the placebo group. Side effects were similar to those experienced by older people, with a brief period of flu-like symptoms. The committee was tasked with considering whether the benefits outweighed the risks; given the minor side effects and the increasingly obvious benefits of vaccination , it's not a surprise that the vote in favor of approval by the committee was 14 in favor, none opposing, and a single recusal. The CDC director, Rochelle Walensky, is overwhelmingly likely to follow the committee's recommendation, most likely before the day is over. (We'll update this story if and when this occurs.)

Enlarge / Picture of vials of Russia's Sputnik V vaccine against the novel coronavirus disease, COVID-19, seen at the Cotahuma Hospital in La Paz, Bolivia. (credit: Jorge Bernal/Getty Images )

Yesterday, the people behind Russia's leading vaccine, termed Sputnik V, issued a preliminary analysis of its function. The news was quite good: while the trial is ongoing and final results will have to wait, the interim data suggest that the vaccine could be over 90 percent effective.

Sputnik V is based on similar technology to the vaccines being developed by Johnson & Johnson and the Oxford/AstraZeneca collaborations. Strikingly, however, the preliminary efficiency is quite a bit higher than those vaccines are showing, and it's not clear how the Sputnik-specific features could possibly account for the difference.

Sounds great!

The results come out of a Phase III clinical trial involving roughly 21,000 participants being run in Moscow. Participants were all over the age of 18, hadn't received other vaccinations recently, weren't pregnant or drug users, and met a number of other criteria. PCR-based SARS-CoV-2 tests were performed at enrollment, and participants were also tested for the presence of antibodies against the virus.

Enlarge (credit: CDC.gov )

As the world races to get vaccines into arms, one of the most concerning coronavirus variants appears to be getting a little more concerning.

Researchers in the UK have detected at least 15 cases of B.1.1.7 variants carrying an additional mutation: E484K—a mutation already seen in other concerning variants , and one that may make current vaccines less effective at preventing infection. The B.1.1.7 variant, first identified in the United Kingdom, is already known to spread more easily among people than earlier strains of the pandemic coronavirus SARS-CoV-2. And according to some preliminary evidence, it may cause more severe disease.

So far, B.1.1.7 variants carrying E484K appear rare. On Monday, Public Health England reported in a technical briefing that it had detected E484K in just 11 B.1.1.7 variants among more than 200,000 viruses examined. For now, it’s unclear if the augmented mutants will take off and become dominant in the population or fizzle out. It’s also not entirely clear what the addition of E484K means for B.1.1.7 in people. Preliminary laboratory experiments suggest the mutation alone and its presence in B.1.1.7 specifically may help the virus evade immune responses. But more studies and clinical data are necessary to understand the full effect of the new addition.

Enlarge (credit: Getty Images )

Last December, when Caleb Chung, a 12-year-old in Durham, North Carolina, first heard from his dad that he might be eligible for a local clinical trial of a COVID-19 vaccine, his reaction was a little muted. He was “interested,” he tells me over Zoom. Not excited, exactly, not jumping for joy at the thought of joining the rarefied ranks of the immune. Interested. He had heard about side effects , for one thing, while watching the news with his parents. But mostly he just wasn’t sure what to make of the idea.

So Caleb and his dad, a pediatrician who works with adolescents, started talking. They covered the science of creating vaccines and testing them and how trials had helped bring vaccines to vulnerable people in the past. Plus, Caleb missed seeing his friends indoors, and seventh-grade Zoom school was slow. Getting shots to more people would bring a quicker end to the tedium. So he signed up. In late December, he got his first shot of what was either the Pfizer-BioNTech vaccine or a placebo. Then, three weeks later, he received his second. Both times, he kept a daily log of how he was feeling, recording a slight fever and soreness in his arm on day two. He took it in stride. “I hope this means I got the vaccine,” he says.

At the moment, two COVID-19 vaccines have been greenlit for emergency use by the US Food and Drug Administration, but both are only available to people older than Caleb. The Moderna vaccine is authorized for people over 18, while Pfizer’s is allowed for people as young as 16 because people that age were included earlier in its trials. But that could be changing. Last week, Pfizer officials announced they had finished enrolling more than 2,200 people in an expanded vaccine trial that includes kids as young as 12, and Moderna is currently in the process of signing up teens. That likely sets the stage for the companies to include teens in their requests for FDA approval, expected later this spring.