Abstract

This lab report aims to discuss the findings of multiple studies performed to test the function, efficacy, and safety of inhalation vaccines. Intramuscular vaccines, those that are injected through the muscle, are not as effective as they can be, simply because the body has a stronger immune response at mucosal surfaces such as the lining of the lungs. Therefore, several scientists and doctors such as Darrell Irvine and Michael Diamond performed studies to test the efficacy of a vaccine that is inhaled through the nose or mouth, rather than injected through the muscle. They found a significantly greater immune response, and also better protection against the targeted virus, giving a whole new potential to the effectiveness of future vaccines.

Analyzing How Vaccination by Inhalation Can Provide More Effective Protection Than Traditional Methods of Vaccination

Introduction

Since the first vaccine was developed to defend against smallpox in 1796, the method of delivery has never changed. We’ve always used some sort of injection, usually through the muscle. It’s been the easiest way for health professionals to deliver a vaccine, and there was no real need for a new method. However, that is no longer the case. The rise of the current COVID-19 pandemic has created a new demand for vaccine administration that we haven’t experienced since the Spanish flu pandemic over a century ago. We need to administer vaccines to everyone quickly, safely, and efficiently. This has led to research into delivering vaccines by inhalation. It has been known by scientists that the immune system’s response to a pathogen at a mucosal surface, such as the lungs or gastrointestinal tract, is often stronger than one at a muscular surface, simply because pathogens tend to enter the host through those mucosal surfaces. “Because the lungs are constantly being exposed to pathogens from the air, they likely have a high level of immune defense activity, and therefore represent an efficient site for immune protection against airborne pathogens.” (Cell Press, par. 4). “[The mucosal tissue] contains high levels of immune proteins, called IgA, that give better protection against respiratory viruses.” (Paton, par. 5). This has led to scientists and researchers working on developing a vaccine that targets those specific mucosal surfaces, to trigger a stronger immune response and consequently give the patient better immunity against the virus.

Methods and Materials

Several studies were conducted and are still being conducted to test the efficacy and safety of delivering vaccines through inhalation. Since scientists and researchers are trying to innovate a method of delivery that allows the vaccine to enter through mucosal surfaces, they needed a new approach. Dr. Darrell Irvine, a professor at MIT, was a senior author on a study performed to test a new form of vaccine delivery. He and his team aimed to create a peptide vaccine that would enter through the lung’s mucosal surfaces. A peptide vaccine would be safer and more effective than a vaccine with the live virus. (Trafton, par. 8). Irvine and his team attached the peptide vaccine to a protein called albumin to help it cross the mucosal barrier and began to test its effectiveness compared to intramuscular vaccines in mice. (Trafton, par. 10). Several other studies were done in a similar manner, such as Dr. Wadih Arap and Dr. Renata Pasqualini. They also used a protein to deliver a peptide vaccine through the mucosal surface, just a different one than the albumin used by Dr. Irvine. (Cell Press, par. 7). Michael Diamond, an infectious disease specialist at Washington State University also conducted similar research to test the efficacy of this new delivery method. (Paton, par. 7).

Results

The various research conducted on this specific type of vaccine delivery all yielded similar results. In Dr. Irvine’s study, he found that “this type of delivery generated a 25-fold increase in memory T cells in the mouse lungs, compared to injecting the albumin-modified vaccine into a muscle site far from the lungs.” (Trafton, par. 12). The efficacy of this new lung-delivered vaccine was significantly larger than the traditional method of injecting it through the muscles, which is expected because of the way the body responds to pathogens at mucosal surfaces. Diamond’s study also yielded similar results. When his team tested their vaccine on mice, the mice all had much stronger immune responses and created more antibodies, especially in the nose and lungs. (Paton, par. 8). In Arap and Pasqualini’s study, their method of delivery also produced “very strong and sustained immune responses, without producing toxic side effects.” (Cell Press, par. 8). It is evident from all the research conducted on inhalation vaccines that they are significantly more effective than intramuscular vaccines, and don’t pose any greater a risk since they both use peptide vaccines instead of live viruses.

Discussion

The implications of these results are vast, especially in the current pandemic we are living in. Firstly, all current vaccines against COVID-19 have yet to reach 100% efficacy, the largest of which being the Pfizer vaccine with a 95% efficacy (Katella, par. 5). However, that’s just the Pfizer vaccine, and Moderna with a similar efficacy. Other vaccines, such as the Johnson & Johnson vaccine, which has a 72% efficacy, are much lower. (Katella, par. 27). Had these vaccines all been developed to be delivered through the respiratory system, the efficacy could be much higher because it would provoke a much stronger immune response and incite more antibody production. However, efficacy isn’t the only factor to consider. Inhalation vaccines are also much more versatile than intramuscular ones. They can be administered faster without the need for a healthcare professional and can also be stored with less strict conditions. (Paton, par. 9). This means that they will cost less to produce, store, and administer, making mass production and administration a much smoother and easier task. Having an inhalation vaccine during this COVID-19 pandemic could’ve served the world well, potentially ending the pandemic within months or even weeks of development of the first inhalation vaccine. It’s an innovation that would benefit the whole world immensely, because having such an easy to store and administer vaccine could allow it to be shipped to third world countries, those that can’t afford to have healthcare professionals at every corner. Human trials by several companies are underway, and the world will hopefully see its first inhalation peptide vaccine soon.

Acknowledgements

I’d like to thank the efforts of all the scientists, researchers, and doctors who contributed to all the studies done on the topic. I’d like to give special thanks to Dr. Darrell Irvine and his team, Dr. Arap and Dr. Pasqualini and their team, and Michael Diamond and his team.

References

Katella, Kathy. “Comparing the COVID-19 Vaccines: How Are They Different?” Yale Medicine, Yale Medicine, 13 Apr. 2021, www.yalemedicine.org/news/covid-19-vaccine-comparison.

Paton, James. “Inhaled Vaccines Aim to Fight Coronavirus at Its Point of Attack.” Medical Xpress – Medical Research Advances and Health News, Medical Xpress, 13 Oct. 2020, medicalxpress.com/news/2020-10-inhaled-vaccines-aim-coronavirus.html.

Trafton, Anne. “Vaccination by Inhalation.” MIT News | Massachusetts Institute of Technology, MIT News Office, 19 Mar. 2021, news.mit.edu/2021/vaccination-inhalation-0319.

Cell Press. “Inhaled vaccine induces fast, strong immune response in mice and non-human primates.” ScienceDaily. ScienceDaily, 10 Dec. 2020, www.sciencedaily.com/releases/2020/12/201210112118.htm.