Moderna Vaccine Not Effective Against “Mutant” South African COVID Strain, But Works With UK Variant

Moderna’s latest trial data includes some good news…and some bad news.

The good news is that the biotech company’s original COVID jab is effective against two mutations of SARS-CoV-2 which were first isolated in the UK and South Africa, respectively.

The bad news is that, at least when it comes to the South African variant, Moderna’s jab is much less effective than scientists had expected. That’s a bad sign, because it suggests the vaccines might not perform as well, particularly in elderly patients, or that the immunity they provide might not last as long, as various strains of the virus continue to mutate.

However, perhaps due to the optimistic tone of the press release, investors took the news as a positive and bid Moderna shares higher.

Here’s some more details from the FT:

Laboratory tests show Moderna’s Covid-19 jab still works against the variant named 501.V2, which emerged in South Africa, and B.1.1.7, which was first discovered in the UK, the company said. But it warned that the neutralising antibody response to 501.V2 was sixfold lower than to the original variant, raising concerns that immunity to it may wane significantly, particularly in older people.

Moderna has launched a series of trials intended to test its vaccine’s efficacy against several different mutant strains.

But don’t worry, because even though Moderna’s CEO acknowledges that this is an extremely serious situation and the company is preparing for the worst-case scenario, everything is going to be okay.

Stéphane Bancel, Moderna CEO, said the company was preparing for a “worst-case scenario,” even though he had “zero concerns” about the vaccine’s efficacy in the coming months.  “If something needs to be done in the summer, we’ll do something, but we cannot be late,” he told the Financial Times. “We don’t want the virus to win, we want the human race to win.”

That doesn’t exactly sound reassuring.  As it turns out, Moderna is the first vaccine maker in the West to announce a trial for a booster against a new variant, after having its initial jab authorised across the world including in the US, the EU and the UK. Its messengerRNA technology can be quickly adapted for new variants.

The company is working with the US National Institutes of Health on the trials. Mr Bancel said a few thousand trial participants would be given a booster shot, divided into two groups: one to receive the original vaccine again, and another to get a new vaccine formulated to target 501.V2. The trial will also test to see what dose is needed for a booster.

Read the full press release below:

CAMBRIDGE, Mass.–(BUSINESS WIRE)–Jan. 25, 2021– Moderna Inc. (Nasdaq: MRNA), a biotechnology company pioneering messenger RNA (mRNA) therapeutics and vaccines, today announced results from in vitro neutralization studies of sera from individuals vaccinated with Moderna COVID-19 Vaccine showing activity against emerging strains of SARS-CoV-2. Vaccination with the Moderna COVID-19 Vaccine produced neutralizing titers against all key emerging variants tested, including B.1.1.7 and B.1.351, first identified in the UK and Republic of South Africa, respectively. The study showed no significant impact on neutralizing titers against the B.1.1.7 variant relative to prior variants. A six-fold reduction in neutralizing titers was observed with the B.1.351 variant relative to prior variants. Despite this reduction, neutralizing titer levels with B.1.351 remain above levels that are expected to be protective. This study was conducted in collaboration with the Vaccine Research Center (VRC) at the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH). The manuscript has been submitted as a preprint to bioRxiv and will be submitted for peer-reviewed publication.

The two-dose regimen of the Moderna COVID-19 Vaccine at the 100 µg dose is expected to be protective against emerging strains detected to date. Nonetheless, Moderna today announced its clinical strategy to proactively address the pandemic as the virus continues to evolve. First, the Company will test an additional booster dose of its COVID-19 Vaccine (mRNA-1273) to study the ability to further increase neutralizing titers against emerging strains beyond the existing primary vaccination series. Second, the Company is advancing an emerging variant booster candidate (mRNA-1273.351) against the B.1.351 variant first identified in the Republic of South Africa. The Company is advancing mRNA-1273.351 into preclinical studies and a Phase 1 study in the U.S. to evaluate the immunological benefit of boosting with strain-specific spike proteins. Moderna expects that its mRNA-based booster vaccine (whether mRNA-1273 or mRNA-1273.351) will be able to further boost neutralizing titers in combination with all of the leading vaccine candidates.

“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,” said Stéphane Bancel, Chief Executive Officer of Moderna. “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.”

First detected in September 2020 in the United Kingdom, the SARS-CoV-2 B.1.1.7 variant has seventeen mutations in the viral genome with eight mutations located in the spike (S) protein. The B.1.351 variant, first detected in South Africa, has ten mutations located in the spike (S) protein. Both variants have spread at a rapid rate and are associated with increased transmission and a higher viral burden after infection1,2.

The in vitro study assessed the ability of mRNA-1273 to elicit potently neutralizing antibodies against the new SARS-CoV-2 variants, using sera from eight Phase 1 clinical trial participants (aged 18-55 years) who received two 100 µg doses of mRNA-1273, and separately using sera from non-human primates (NHPs) immunized with two doses of 30 µg or 100 µg of mRNA-1273.

For the B.1.1.7 variant, neutralizing antibody titers remained high and were generally consistent with neutralizing titers relative to prior variants. No significant impact on neutralization was observed from either the full set of mutations found in the B.1.1.7 variant or from specific key mutations of concern. Although these mutations have been reported to lessen neutralization from convalescent sera and to increase infectivity, sera from the Phase 1 participants and NHPs immunized with mRNA-1273 were able to neutralize the B.1.1.7 variant to the same level as prior variants.

For the B.1.351 variant, vaccination with the Moderna COVID-19 Vaccine produces neutralizing antibody titers that remain above the neutralizing titers that were shown to protect NHPs against wildtype viral challenge. While the Company expects these levels of neutralizing antibodies to be protective, pseudovirus neutralizing antibody titers were approximately 6-fold lower relative to prior variants. These lower titers may suggest a potential risk of earlier waning of immunity to the new B.1.351 strains.