Nasal COVID-19 Vaccines – What You Need to Know
Nasal COVID-19 vaccines mimic the first step in the airborne exposure process, which in turn induces both systemic and mucosal immune responses. But there are a few issues to keep in mind before you take these nasal COVID vaccines. These vaccines are not recommended for older adults.
Intranasal COVID-19 vaccines mimic first step of exposure to airborne pathogens
The safety and efficacy of COVID-19 vaccines have been questioned. There are some concerns about the potential for the COVID-19 vaccine to induce ADE, or antibody-dependent enhancement of disease, in the recipient. ADE occurs when the host produces cross-reactive but subneutralizing antibodies to one virus serotype, resulting in an increased level of disease. ADE is most commonly associated with the dengue virus. It occurs when the immune system becomes infected with a virus that replicates in macrophages and triggers an abnormal response.
Intranasal COVID-19 vaccinations can boost the body’s immune response to the virus. The nasal vaccine mimics the first step of natural exposure, and helps prepare the body’s immune system to defend itself. In addition, intranasal vaccines are painless and require no specialised training.
They induce mucosal and systemic immune responses
Vaccinations elicit robust humoral and cellular responses in susceptible individuals against SARS-CoV-2. The exact mechanisms underlying these responses remain unclear. Nasal COVID-19 vaccines induce both mucosal and systemic immune responses, and they are associated with decreased neutralizing antibodies and higher cellular immunity.
The NALT plays a critical role in the immune response, activating immune cells including T helper 1 (Th1) and Th2-cells, NK cells, resident M and B cells, and immunoglobulin A. Similar immune activation is also observed in GALT (gut-associated lymphoreticular tissues). COVID-19 induces complex interplay of inflammatory, coagulative, and immunological cascades. Despite these promising outcomes, there is no approved therapeutic or prophylactic treatment for this disease.
They are not approved for older adults
The FDA has not yet approved nasal COVID-19 vaccines for older adults. These vaccines do not contain live virus, which is the main concern about them. Rather, they create an immune response in the respiratory tract. This response can limit the transmission and infection of COVID-19.
However, the CDC and FDA have issued an emergency use authorization for the COVID-19 vaccine. They also approved the MenQuadfi (MenACWY) conjugate vaccine, a vaccine that prevents invasive meningococcal disease. Moreover, the FDA has also approved Fluad Quadrivalent, a vaccine that prevents influenza.
