As worrying coronavirus variants appear to be popping up and spreading everywhere, lead vaccine manufacturers are wasting no time trying to address the growing threat.
This week, Moderna and its partners Pfizer and BioNTech announced that they have launched new clinical trials for vaccinations to increase the efficacy of their authorized vaccines against new ones, regarding SARS-CoV-2 variants – mainly B.1.351, a variant that first identified in South Africa. .
In a set of studies published in the New England Journal of Medicine last week, the Modern mRNA vaccine and the Pfizer / BioNTech mRNA vaccine detected antibodies in vaccines that could neutralize the B.1.351 variant. But the levels of those neutralizing antibodies were significantly lower than those seen against previous versions of the virus. (Both vaccines performed well against the B.1.1.7 variant, first identified in the UK, which is expected to become the dominant strain in the US next month.)
Although vaccine manufacturers still expect the current vaccines to protect against B.1.351 and other variants – at least to ward off serious illnesses and deaths – they are preparing for the worst. The good news is that the design of the mRNA vaccine is relatively easy to adapt to the variants.
The variants contain dangerous mutations in critical parts of their ear protein, making the virus more transmissible and virulent than the original SARS-CoV-2. The adaptation of the current vaccines to target the variants simply involves the code of the spike mRNA molecule used in both vaccines to match the variants’ mutations. Moderna and Pfizer / BioNTech said such adjustments could only take a few weeks to complete.
But the vaccine manufacturers are starting their fight against the variants with an even simpler strategy: to give people a third uptake of current vaccines. The idea is that a third dose on top of the current two-dose regimen could further increase the levels of antibodies and other protective immune responses. As mentioned above, the data so far indicate that the vaccines encourage the production of neutralizing antibodies against the variants – this is relatively low. A third shot – or a second booster – can further increase levels and increase protection.
More of the same
Pfizer and BioNTech announced Thursday that they have begun an experiment with the three-shot strategy. They use 144 people who were vaccinated in their Phase I trial six to 12 months ago. After the third survey, the companies will look at side effects as well as levels of antibodies in the participants. As the companies put it, the trial will assess the promotion of the vaccine.
“Although we have not seen any evidence that the varying variants result in a loss of protection by our vaccine, we are taking several steps to take action and be ready if a strain resists the protection afforded by the vaccine. , “said Pfizer. Albert Bourla, chief executive, said in a statement. “This promotion study is critical to understanding the safety of a third dose and immunity to circulating strains.”
Meanwhile, the companies are also working on plans to export a B.1.351-specific vaccine.
Moderna, meanwhile, continues its vaccine-specific vaccinations. It has already manufactured a B.1.351-specific vaccine which it has sent to collaborators of the National Institutes of Health for initiating clinical trials. In addition, Moderna will also be testing a combination vaccine that contains both the original vaccine and the B.1.351-specific component. Finally, the company has already begun a trial to test a third survey of its current vaccine.
“While we want to defeat COVID-19, we must be vigilant and proactive as new variants of SARS-CoV-2 emerge,” Moderna CEO Stéphane Bancel said in a statement. ‘Taking advantage of the flexibility of our mRNA platform, we are quick to check for vaccine updates that address emerging variants of the virus in the clinic. Modern is committed to making as many updates to our vaccine as possible until the pandemic is under control. ”
The U.S. Food and Drug Administration released new guidelines this week on how vaccine manufacturers are authorized for their updated vaccines. In short, the regulatory agency has made it clear that companies can submit data from smaller trials – relative to the massive ones they needed to prove the effectiveness of their initial authorization. The trials may also focus on immune responses seen in participants to evaluate efficacy rather than the number of COVID-19 cases in vaccines compared to those in a placebo group.