The FDA has authorized new booster shots targeting Omicron subvariants. The boosters, approved today (Wednesday), were developed by Pfizer and Moderna. They will be available to the public in the United States as early as next week. 

BENJY RENTON; bhrenton@gmail.com, @bhrenton 
    Renton is a research assistant supporting Ariadne Labs’ Covid-19 vaccine delivery work.

ROB SWANDA; contact via https://www.drswanda.com/contact, @ScientistSwanda
     Swanda is an mRNA biochemist and a science communicator known for his popular online educational videos about topics involving infectious diseases and immunology. 

MEGAN RANNEY; megan_ranney@brown.edu 
    Ranney is a practicing emergency physician, researcher, and advocate for innovative approaches to public health at the School of Public Health at Brown University. 

Renton told the Institute for Public Accuracy on Wednesday: “These updated boosters will be a key tool for those at high risk of severe disease. We can expect more data behind today’s decision tomorrow at the CDC’s Advisory Committee on Immunization Practices.” Renton stressed the importance of these boosters for vulnerable Americans. “With every successive booster,” he said, “we have seen lower uptake and widening disparities among racial/ethnic lines. Additionally, many of those over the age of 50––who are at higher risk for severe illness––have not received their first or second booster.”

Last week, Swanda released a viral Twitter video summarizing how the bivalent mRNA vaccine boosters for Covid-19 work. Swanda’s videos seek to make science content “accessible to anyone… I want to create scientific content that is not hidden behind paywalls and that is available in multiple languages,” he told the Institute for Public Accuracy. “As someone who didn’t grow up with clear, understandable access to science information, this issue is close to my heart.”

Swanda’s video explains how the mechanism of immune response action is the same as the vaccine series previously developed by Pfizer and Moderna. In these shots, however, the vaccine administers two sets of instructions in one shot, which includes protection against newer strains of the virus that have evolved since the first vaccines were rolled out in early 2021.

Swanda said: “The bivalent mRNA boosters are a way for our immune systems to ‘upgrade’ their response to current and future mutated forms of SARS-CoV-2. This vaccine allows our cells to remember what both the ancestral strain of SARS-CoV-2 looks like, and what the Omicron variant of SARS-CoV-2 looks like. Due to the high mutation rate of SARS-CoV-2 and the increased infections recently, the Covid-19 vaccine needed to be updated. The concept of upgrading a vaccine is not a new concept, as this is what is done each year for the flu. Additionally, having a vaccine that targets multiple strains of a pathogen is also not new. Various vaccines, including HPV and Pneumococcal, target several strains of the pathogen.” Swanda noted that companies are working on additional boosters using a variety of technologies, including the possibility of a nasal spray to reduce transmission or a combination seasonal vaccine that would fold flu and Covid-19 shots together.

Ranney told the Institute for Public Accuracy: This “booster approval is really exciting; it marks the first time that our vaccines will be targeted towards the variants of Covid-19 that are currently in dominant circulation. We all know how well the original vaccine worked against the original strain of the virus––but variants have led to decreases in the vaccine’s efficacy.” 

Ranney calls the boosters “potentially transformative” new strategies to combat the virus. The boosters represent new targeted vaccines for the next phase of the pandemic, but scientists will have to continue to modify tools for prevention. Ranney cautions that BA4 and BA5––the Omicron variants that are currently dominant worldwide––may not be dominant forever. Further, “we have seen low uptake of boosters in the last year and a half. My hope is that 25 to 30 percent of the population, especially immunocompromised and older folks, will get these shots. That could potentially be really impactful.”