Does the Moderna vaccine work against the new COVID-19 variants?

does moderna vaccine work against variants
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  • This story is regularly updated for relevance. Last updated: July 12, 2021

Moderna, one of the three vaccines to be approved in the U.S., announced on Jan. 25 that its version of the vaccine has been shown to work against the coronavirus variants that have put much of the world on edge.

The U.K. variant, aka alpha, and the South African variant have spread across much of the world, worrying people about their potentially higher infectious rates, whether they’re more deadly than the original strain of COVID-19, and how much younger adults who have not yet been vaccinated are in danger. People have also questioned whether the current vaccines in the U.S., the ones made by Pfizer and Moderna, can work against those variants.

Moderna said the answer is yes.

But what about the delta variant—the one that originated in India that, as of early July, had become the most dominant strain in the U.S. and the one that a former Biden administration official called, “COVID-19 on steroids?” According to Dr. Anthony Fauci, both Moderna and Pfizer are about 88% effective against that version.

In May, researchers also showed Moderna was likely effective against delta. “What we found is that the vaccine’s antibodies are a little bit weaker against the variants, but not enough that we think it would have much of an effect on the protective ability of the vaccines,” Nathaniel “Ned” Landau, the senior author of a research study that determined this, told AFP.

In a news release issued on Jan. 25, Moderna said its vaccine “produced neutralizing titers against all key emerging variants tested, including B.1.1.7 and B.1.351, first identified in the U.K. and Republic of South Africa, respectively.” But Moderna also said it is testing “an additional booster dose” of its vaccine that it hopes will increase the vaccine’s effectiveness against the South African strain.

In late December, the U.K. variant was discovered in California, Colorado, and a handful of other states. Fauci, the nation’s top infectious disease expert, said he thought the Pfizer and Moderna vaccines would still work against the variants. Now, Moderna has confirmed it. But the company still plans to evolve its vaccine to keep pace with the variants.

“As we seek to defeat the COVID-19 virus, which has created a worldwide pandemic, we believe it is imperative to be proactive as the virus evolves. We are encouraged by these new data, which reinforce our confidence that the Moderna COVID-19 vaccine should be protective against these newly detected variants,” Stéphane Bancel, Moderna’s CEO, said in a statement. “Out of an abundance of caution and leveraging the flexibility of our mRNA platform, we are advancing an emerging variant booster candidate against the variant first identified in the Republic of South Africa into the clinic to determine if it will be more effective to boost titers against this and potentially future variants.”

Dr. Tal Zaks, the company’s chief medical officer, said the booster is basically an insurance policy. “I don’t know if we need it,” Zaks told the New York Times, “and I hope we don’t.”

In April 2021, two more independent studies showed Moderna was effective against multiple variants. “The take-home message is that the vaccines are going to work against the New York variant and the South African variant and the U.K. variant,” Nathan Landau, a virologist at N.Y.U.’s Grossman School of Medicine, told the New York Times.

Said Michel Nussenzweig, an immunologist who helped publish one of the studies: “We’re not seeing big differences. … Get vaccinated.”

Now that a new COVID variant has been discovered in Vietnam, more questions likely will be raised about Moderna’s response to it.

Dr. Supriya Narasimhan, the chief of infectious diseases at Santa Clara Valley Medical Center in California, told Nautilus recently that the currently available vaccines could be tweaked to combat the coronavirus variants.

“We we have not yet distributed enough vaccine to see what vaccine selection pressure does to the virus,” Narasimhan said. “In other words, the vaccine pressure may cause the emergence of more mutations (I certainly hope this does not happen), and if it does, we may have to tweak the vaccine in the future. But what the last year has shown is that we are capable of engineering a novel vaccine in a span of months, so re-engineering them to include mutations is not insurmountable. What seems a bigger issue is the culture of denialism and vaccine hesitancy in the community—people have to take the vaccine for it to work.”

Here’s how Vox explained how Moderna could accomplish that: “… Developers only need to modify the code of DNA or mRNA to tweak the vaccine to reorient it to new variants, something they can do quickly if necessary. But while it may be possible to alter the vaccine to adapt to new mutations, it’s not ideal: It requires expensive changes in the vaccine production process and eats up valuable time.”

The Pfizer vaccine also appears to work against the variants. As noted by CNN, some of the antibodies created by the vaccines were not effective against some of the mutations, but the many varied antibodies that appeared in the bodies of volunteers was enough to keep the mutations at bay overall. Those who have received both doses of the Pfizer vaccine reportedly have had positive responses against the U.K. and South Africa variants.

“When you start putting all these mixtures of antibodies together, what it means is that together they can take care of the variants,” Dr. Michel Nussenzweig of the Rockefeller University, told CNN.

Meanwhile, researchers said the AstraZeneca vaccine could be ready to fight the variants by the fall of 2021, because, according to the BBC, “tweaking [the] vaccine was a relatively quick process.” But it’s still not approved for use in the U.S. It’s also had issues with whether its data is accurate, but so far, AstraZeneca hasn’t been shown to protect against the variant from South Africa.

On March 30, it was reported that the Moderna and Pfizer versions were “robustly effective in preventing infections in real-life conditions,” according to the Washington Post. In a study of thousands of healthcare workers, police, and firefighters, it was found that those vaccines reduced the risk of COVID infection by 90% after they were fully vaccinated (and 80% after just one dose).

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Sources: Moderna, CNN, New York Times

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