The continued evolution of SARS-CoV-2 into new variants, each as contagious or more contagious than the last, underscores the continued need to update our vaccine defenses against the virus. For which they are designed, the virus evolves to become more contagious and evade our last immune defenses. This push underscores the need for a universal, potentially revolutionary vaccine that can neutralize the entire bureaucracy of SARS-CoV-2 and even other similar coronaviruses. A recent study by Peter Halfmann and colleagues at the University of Wisconsin offers promising indications that this universal vaccine is on the horizon.
In the 4 years and millions of deaths since the virus emerged in early 2020, we have noticed several iterations of the COVID-19 vaccine. Many corporations have worked with their federal governments through multiple methods, aggregating mRNA, killed viruses, and purified subunits, to expand vaccines with varying efficacy. The most effective were the mRNA vaccines from Pfizer and Moderna.
The first Pfizer and Moderna vaccines were announced in 2021 as a two-dose regimen, followed by a booster six months earlier. At the end of 2022, they released updated bivalent vaccines targeting Omicron BA. 4 and BA. 5. Finally, at the end of 2023, they released another updated booster for Omicron XBB. 1. 5. The similarities between this strategy and what we see with annual flu shots are obvious: An updated booster is rolled out each year to target the strain of the virus that’s been circulating lately.
Over time, the virus develops a number of mutations in the spike protein and other genes that contribute to immune evasion, resulting in a new variant and reduced efficacy of the newer vaccine. The need for a universal vaccine is as evident as day. however, it has not yet been realized.
Halfmann and his colleagues seek to fill this gap in their study published in Nature, by creating a vaccine that neutralizes not only the bureaucracy of SARS-CoV-2, but also transmits coronaviruses to SARS-CoV-2 and SARS-CoV. a strategy to avoid outbreaks in the long term.
Halfmann and his colleagues expanded their vaccine to include elements of 8 Spike proteins, namely the 614D, BA. 1, BA. 5, BA. 2. 75. 2, and XBB variants of the SARS-CoV-2, SARS-CoV, and bat coronaviruses SHC014 and WIV1.
To maximize the universality of their vaccine, they used a spike protein nanoparticle platform instead. Imagine making a salad with just lawn ingredients. The spike proteins of a SARS-CoV-2 particle are identical, like a lawn with only lettuce. The nanoparticle platform, known as MS2-SA, makes it possible to bind many spike proteins to the same base, such as a lawn with lettuce, tomatoes, radishes and cucumbers, resulting in a much more physically powerful salad.
The nanoparticle platform can incorporate various protein antigens, allowing the progression of many other multivalent vaccines or “cocktails” that offer broad protection.
By testing combinations, they discovered a trivalent candidate with promising efficacy data.
A mixture of nanoparticles, adding 614D, SHC014, and Omicron XBB (shown in the figure above in blue), created a physically powerful cover point that not only opposes Omicron’s dominant bureaucracy but also opposes bat coronaviruses SHC014 and WIV1, indicating a wide diversity of neutralization potential in this branch of the coronavirus lineage, namely, SARS-CoV-2 sarbecoviruses, SARS-CoV, and some coronaviruses that cause the usual cold. In particular, this mixture may not neutralize some coronaviruses.
In addition, the vaccines were more than functionally effective in vitro; They protected live hamsters from viruses. The trivalent mixture of 614D, SHC014 and Omicron XBB particularly reduced lung virus titers in hamsters inflamed with BA. 5 and XBB. 1. Similar effects are noted when hamsters are inflamed with bat coronaviruses WIV1 or SHC014 and are vaccinated. with the trivalent vaccine.
There are three main takeaways from this research. First, the progression of a broadly protective vaccine is to end the evolutionary cat-and-mouse game with SARS-CoV-2. The trivalent vaccine from Halfmann and colleagues may be the solution.
Second, the ability of this trivalent vaccine to produce cross-reactive neutralizing antibodies and provide full coverage against coronaviruses in animal models suggests that it could be an effective strategy for potential long-term coronavirus outbreaks.
Third, if this vaccine proves effective in clinical trials, vaccine methods could be adapted to target other emerging viral threats beyond SARS-CoV-2 and its variants. This means that we can simply adjust the viruses used in the formula to locate anything that works if many other viruses threaten an outbreak in the near future.
I look forward to further testing and advancement of this vaccine and urge that its availability to consumers be accelerated to create a strong defense against the ongoing COVID-19 pandemic.