Inhaled COVID Vaccine Could Protect Against Variants by Targeting Lungs

A COVID vaccine that is inhaled rather than injected could provide protection against the disease, according to the researchers developing it.

It is thought that the vaccine could be particularly effective compared to a traditional injected vaccine since it would be administered directly to the respiratory system.

In addition, the researchers hope that the vaccine could also provide long-lasting protection against COVID since it targets three parts of the SARS-CoV-2 virus rather than just the spike protein, which has shown a remarkable ability to mutate throughout the pandemic.

However, the inhalable vaccine is nowhere near approval for humans yet and the most recent details are based on preclinical data from animal models. The proposed vaccine is yet to complete the first phase of clinical trials.

COVID vaccines, which are proven to be safe and effective at protecting people against the disease, have proven contentious for some people throughout the pandemic due to vaccine hesitancy around the world. There have also been concerns about their effectiveness waning over time as new variants emerge.

The inhalable vaccine, being developed by researchers at McMaster University in Canada and Southern Medical University in Shenzhen, China, could help overcome some such hurdles to COVID vaccination.

"There is a pressing need to develop next-generation vaccine strategies for broader and long-lasting protection," the researchers say in a new study published in the journal Cell on February 8th. They added that the strategy of making a new vaccine for each variant is one such strategy but described this as "cumbersome and expensive".

Instead, they propose a type of recombinant viral-vectored vaccine—the same type of vaccine as the AstraZeneca and Johnson & Johnson shots—that could target more variants in a broader way by making use of T-cells. These are immune system cells that target specific foreign particles in the body and have been associated with longer-lasting immunity against COVID than antibodies.

The Canada/China research so far suggests that by inhaling the vaccine, "all-around respiratory mucosal immunity" could be induced against ancestral COVID as well as the Alpha and Beta variants.

The researchers tested their vaccine prototype on mice via a traditional muscular injection or an inhaled or intranasal method. Their findings suggested that the inhaled method was better in terms of inducing antibodies as well as T cells in mucus tissue.

However, the study does have limitations. Namely, mice and humans are biologically different and it remains to be seen whether the results will be similar in human studies. It also did not specify effectiveness against more recent variants like Delta or Omicron.

A stock photo shows an illustration of some lungs overlaid with depictions of the SARS-CoV-2 virus. An inhalable vaccine could be superior to an injected one, researchers have suggested. Natali_Mis/Getty