10 Questions About Inhaled COVID-19 Vaccine
Q1: Why choose inhaled COVID-19 vaccine?
A: Inhaled COVID-19 vaccine solves the inconvenience of crowds, time, and location that need to be concentrated for injection and vaccine injection, as well as the risks of operation, safety and cross-infection.
Q2: How do inhaled vaccines work?
A: Vaccination induces a systemic immune response, which is not specifically targeted at the pathogen-infected area. At the same time, inhaled vaccines specifically target mucosal surfaces - nose, throat and lungs, the entry points of pathogens-to induce local immune responses.
Research in the 1960s and 1970s showed that inhaled influenza and measles vaccines provided some protection.
Q3: Why choose Mesh Nebulizer?
A: The mesh nebulizer is a new generation of atomized inhalation devices. It has the characteristics of both compression nebulizer and ultrasonic nebulizer. Using electronic high-frequency oscillation (no harm to humans or animals), through the high-frequency resonance of the atomizer, the liquid water molecular structure is dispersed to form particles of about 3-30μm, which can be targeted at the nasal cavity, oral cavity, pharynx, and throat respectively. Targeted drug delivery to the lungs and targeted adjustable atomized particles to achieve high-efficiency absorption. The FEELLIFE mesh nebulizer uses piezoelectric ceramic titanium alloy sheets, which have the advantages of stable temperature, stable rate, extremely small drug residue, rechargeable, and convenient to carry. It is very suitable for small doses of vaccines and short-time administration.
Q4: At what age can people get inhaled vaccines?
A: From the design of clinical observation, vaccination has been observed for all age groups over 3 years old, and clinical trial data of the population have been made. All age groups over 3 years old can be vaccinated. It is limited to 18 years of age or older in the early stage, because the adult group is the first to join the group, the data is the most complete and comes out the fastest, so it is recommended that these groups be vaccinated first.
Q5: What kind of COVID-19 vaccine can be atomized?
A: At present, atomization is suitable for adenovirus vector vaccine of COVID-19.
Q6: Are there any side effects from aerosolised vaccines?
A: The COVID-19 vaccine will have different levels of side effects for some people. Compared with injection, the probability of side effects such as fever, headache, muscle and joint aches and so on is greatly reduced with aerosolised vaccine, which is a safer vaccination method.
Q7: Are inhaled vaccine and injection vaccines the same medicine?
A: The formulations and production processes of the inhaled COVID-19 vaccine and the injected vaccine are exactly the same, but the vaccination route is changed, inhaled COVID-19 vaccine is more efficient and safer.
Q8: What are the benefits compared with injected vaccines?
A: Inhaled vaccines can generate mucosal immunity. The traditional way of vaccination generally can only achieve humoral and cellular immunity. If new immunization methods are added, the other two methods can be combined to better protect everyone's health.
Injected vaccines usually require refrigeration and well-trained health personnel, which is problematic in non-industrialized countries and remote areas. On the other hand, inhaled vaccines can be vaccinated through a disposable device without the need for trained personnel, making it easier to vaccinate on a large scale.
It could also appeal to those who are afraid of needles. Also, it is a painless vaccination, suitable for all ages, young and old, with higher vaccination efficiency. It can greatly increase people's willingness to be vaccinated.
Experts said the inhaled vaccine required much lower doses than the injected one, which would make it easier to produce more.
Professors Yuen Kwok-yung and Chen Honglin, from the University of Hong Kong, have developed an inhaled vaccine that is in the early stage of clinical trials. They said injected vaccines would induce a systemic immune response but it was not clear how far that extended into the respiratory tract, according to a HKU statement in March. Nasal spray vaccines are designed more specifically to induce immunity in the airways and animal experiments show they can also induce systemic immunity. They are also expected to produce a low number of allergic reactions.
Q9: How about the challenges?
A: One paper, by Wouter Hinrichs, from the University of Groningen, published in Expert Review of Vaccines in March suggested that inhaled vaccines, especially when stored in a dry powder form, could be kept for much longer in a stable form than liquid vaccines meant to be injected.
But questions about their durability have yet to be conclusively resolved. While the CanSino study found no serious side effects among the phase 1 participants, it also could not rule out the possibility of such side effects.
Hinrichs's study also found that while the immune response observed in mucosal surfaces was likely to play a key role in defending the respiratory tract from pathogenic invasions, it could also damage the lungs or worsen the effects of the disease if the response was too strong.
Q10: Who else is developing inhaled vaccines?
A: Inhaled vaccines are relatively new and mostly used for influenza, but CanSino is not the only one looking at developing one to tackle Covid-19.
The spray by Yuen and Chen from HKU is designed to offer protection against influenza and Covid-19 and is being developed with the support of the Coalition for Epidemic Preparedness Innovations. Oxford University is also studying the immune responses from the nasal administration of the Covid-19 vaccine it developed with AstraZeneca, with a 30-volunteer initial trial. Another trial to test the safety and immune response of COVI-VAC, a single-dose, intranasal vaccine from the US firm Codagenix, is being tested in Britain. Similar vaccines are also being tested in Australia and India.
However, one proposed nasal spray vaccine, from the US company Altimmune, has been scrapped after it failed to induce a satisfactory immune response.