It’s fall, which means it’s time to get your winter vaccinations up to date. This includes influenza, respiratory syncytial virus (for infants and seniors), and COVID-19 vaccines for those 6 months and older.
While the COVID-19 vaccine conversation has been dominated by the new mRNA vaccines from Moderna Inc. and Pfizer-BioNTech, there is another type of vaccine that uses more traditional vaccine-making techniques, from Novavax Inc. This vaccine has generated interest among some online people who prefer the company’s vaccine’s more proven approach, so here’s what you need to know.
How is Novavax’s vaccine different from mRNA vaccines?
Novavax uses a protein-based vaccine strategy, whereby recipients receive a protein produced by the virus, which the body’s immune system then recognizes as foreign and mounts a response. In contrast, mRNA vaccines contain snippets of mRNA genetic material extracted from the spike protein of the COVID-19 virus.
Novavax makes its vaccine by first inserting a gene for a SARS-CoV-2 viral protein into an insect virus, then using this engineered virus to infect the larvae of a cabbage moth called the armyworm, which allows the virus to make more copies of itself, and of course more copies of the SARS-CoV-2 proteins, which are then used in the vaccine.
Novavax’s chief medical officer, Bob Walker, says this approach nicely mimics the way the SARS-CoV-2 virus naturally infects the body, and could theoretically lead to some advantage in terms of the immune response the vaccine generates, but the company and other researchers are still conducting more detailed studies to see if that’s the case. “The structure is virus-like in how[the body’s]immune cells recognize it — it’s the full-length spike protein, which represents the natural configuration of viral proteins,” Walker says. “And it has certain potential advantages.”
The protein is combined with additional compounds that vaccine manufacturers call adjuvants, which further activate the immune system to boost the body’s response to the virus. “One of the big benefits of adjuvants is that they don’t just act on the antibody side in terms of the immune response, they also activate T cells,” Walker says. “T cells have many functions in the body: one is to fight viruses, and another is to help antibody-producing cells make more antibodies.”
Is the Novavax vaccine approved by the U.S. Food and Drug Administration (FDA)?
Novavax’s COVID-19 vaccine has not yet been approved by the FDA, but it is available in the United States under an emergency use authorization the FDA issued to the company in July 2022, allowing the company to manufacture and distribute the product during the public health emergency while the FDA continues to review more extensive data on safety and effectiveness. Novavax’s vaccine is safe and effective, but the FDA is still reviewing more robust, longer-term data. Novavax has applied for full approval of its COVID-19 vaccine and expects a decision from the FDA by April 2025.
Pfizer-BioNTech and Moderna were the first to receive emergency use authorization in 2020 and are seeking approval of COVID-19 vaccines for adults in 2021 and 2022, respectively. The timeline is shorter, mainly because mRNA technology allows for more efficient vaccine development and manufacturing times. Novavax’s vaccine manufacturing process requires more time and different types of testing, so it took longer to complete the regulatory requirements for approval, Walker said. But “we’re getting faster and more efficient at making vaccines with each passing season, and we think that time gap can be shortened,” he said. “But I’m not sure we can beat the mRNA (tech timeline) just because of the difference in technology and testing requirements.”
Which vaccine offers better protection against COVID-19?
Studies conducted by academic researchers over the past few years have consistently shown few major differences in the immune responses generated by the mRNA and Novavax vaccines. Researchers typically measure this by looking at the levels of neutralizing antibodies produced by the body against SARS-CoV-2, which have been similar for all three vaccines. Some studies have also looked at T-cell responses, which also appear to be similar across the three doses so far.
Do certain vaccines offer better protection against new COVID-19 variants?
Over the summer, the FDA encouraged vaccine makers to target the KP.2 strain of SARS-CoV-2 for the upcoming fall and winter seasons, and studies by Moderna, Pfizer-BioNTech and Novavax have shown that their improved vaccines all offer strong protection against this strain as well as newer strains that have emerged in recent months, as all variants remain related and are part of the Omicron group.
I heard the Novavax vaccine has fewer side effects. Is that true?
A rigorous comparison of side effects and adverse events between the mRNA and Novavax vaccines has yet to be done, with each manufacturer submitting reports of side effects identified in their respective studies to the FDA. However, so far, people who received the Novavax vaccine appear to report fewer symptoms, such as fever, muscle pain, and headaches, than people who received either of the mRNA vaccines. All three COVID-19 vaccines have been associated with an increased risk of inflammation of the heart muscle, or pericarditis and myocarditis, and most of the research on the risks of the Novavax vaccine was conducted outside the United States.
Which vaccine should I get this year?
“The best vaccine is the one that you get in your arm,” Walker said. “We’re in the fortunate position that we have multiple options and don’t have to rely on one technology to achieve a very high level of protection and safety. The FDA has determined that all of these vaccines are safe and effective.”
