According to the Milken Institute COVID-19 Treatment and Vaccine Tracker, there are over 276 vaccines currently in development. Oral and intranasal vaccines are currently in trial phases for use in the U.S., but with injectable vaccination being the most familiar to vaccine developers, this technology has led the way. Other countries, including China, India, and Russia, have approved nasal vaccines, but American versions that are being developed are not ready for approval at this time. Currently, the only option in the United States is the injectable vaccines, which are approved and recommended for use in everyone aged 6 months and older.
Injectable Vaccine
Front-runner injectable COVID-19 vaccines, such as the Pfizer-BioNTech and Moderna vaccines currently being distributed, have led the way because the technology is so well understood by vaccine manufacturers. The urgency of this vaccine means that familiar technologies are the fastest way to produce results. “There has been a persistent interest in developing more vaccines that are given by a mucosal route," says Zhengrong Cui, PhD, professor of molecular pharmaceutics and drug delivery at the University of Texas. “However, injectable vaccines are relatively more straightforward to develop.” The injectable route also ensures that the vaccine is secured in the body to take effect. The sneezing and vomiting responses of the body may risk the ejection of mucosal vaccines. On the downside, injectable vaccines have less thermostability (the ability to maintain efficacy at different temperatures), needles pose a risk for injury to healthcare workers, and injections cause pain. This pain and fear of needles alone may prevent some members of the public from opting for vaccination. Additionally, this technology only offers systemic immunity, meaning that an immune response is only mounted once the virus enters the bloodstream. Although systemic immunity is needed, the oral and nasal routes claim to offer systemic immunity in addition to mucosal immunity.
Mucosal Vaccine
Mucosal vaccines combine both oral and intranasal vaccines under this umbrella term. The reason is that both vaccines work on inducing a mucosal immune response as well as a systemic immune response. A mucosal immune response means that when the virus enters the nasal cavity or mouth, the immune cells of the mucosa (the lining of the nose and mouth) will mount a defense locally. Sarah Browne, MD, infectious diseases specialist and senior director of vaccine development at Altimmune, explains that even after an injectable vaccine, people can still carry the virus in their noses. “Many people do not realize that they may need to wear masks after vaccination,” she says. “While they may be protected against disease, they may still carry [the] virus in their nose.” However, says Dr. Browne, “a vaccine given intranasally could sterilize the nose and block transmission to others. This will help kids go back to school and lower [the] risk of the infection spreading between school friends, teachers, or bringing the virus home to older, more vulnerable household members.”
Intranasal Vaccine
Animal studies of intranasal vaccines have been promising, and scientists are working on developing formulas that are effective for humans. According to one 2022 review study, research is showing promising results for these oral and nasal vaccines against SARS‐CoV‐2 that might become viable alternatives to current injectable COVID-19 vaccines. An intranasal vaccine in development by the biotechnology company Meissa has had more success. Initial results in an ongoing Phase 1 study that began in 2021 showed that its vaccine produced a robust immune response in human participants, but more research needs to be completed before approval is a possibility.
Oral Vaccine
U.K.-based iosBio (formerly Stabilitech) is one company currently trialing an oral COVID-19 vaccine. Similar to intranasal vaccines, the company claims that this route of administration offers mucosal immunity and systemic immunity, thermostability, and wider acceptance in the community. For the adult population, the idea of taking a capsule versus getting a needle may indeed be more appealing. But it should be pointed out that this may not be suitable for adults with pre-existing concerns involving gut problems or absorption issues. Additionally, for most children, swallowing a capsule is not only impractical but poses a choking risk for younger children.
How to Help Children Get Their Shots
For now and in the near future, shots are the only available option for COVID-19 vaccines. Vanessa Anderson, a specialist child health nurse, provides tips for parents and caregivers to help their children through any vaccination.
Be honest with your child. Tell them it will sting a little, but it is quick.Talk about why vaccination is important a few days prior to the appointment. This is especially useful with older children who can see what effect COVID-19 is having around us. Remember to explain it in terms your child will understand, depending on their age.Allow your child to bring a special toy or blanket with them for comfort, and be available for cuddles and reassurance.Be available to hold your child on your lap to allow the provider to give the injection (or nasal vaccine) safely.Consider doing something fun afterward as a treat, something your child can look forward to. See a doctor or nurse that you are familiar with, or that is trained in working with kids, if possible.
The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.
