Harnessing Cellular Immunity for Vaccination against Respiratory Viruses

Abstract

Severe respiratory viral infections, such as influenza, metapneumovirus (HMPV), respiratory syncytial virus (RSV), rhinovirus (RV), and coronaviruses, including severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), cause significant mortality and morbidity worldwide. These viruses have been identified as important causative agents of acute respiratory disease in infants, the elderly, and immunocompromised individuals. Clinical signs of infection range from mild upper respiratory illness to more serious lower respiratory illness, including bronchiolitis and pneumonia. Additionally, these illnesses can have long-lasting impact on patient health well beyond resolution of the viral infection. Aside from influenza, there are currently no licensed vaccines against these viruses. However, several research groups have tested various vaccine candidates, including those that utilize attenuated virus, virus-like particles (VLPs), protein subunits, and nanoparticles, as well as recent RNA vaccines, with several of these approaches showing promise. Historically, vaccine candidates have advanced, dependent upon the ability to activate the humoral immune response, specifically leading to strong B cell responses and neutralizing antibody production. More recently, it has been recognized that the cellular immune response is also critical in proper resolution of viral infection and protection against detrimental immunopathology associated with severe disease and therefore, must also be considered when analyzing the efficacy and safety of vaccine candidates. These candidates would ideally result in robust CD4+ and CD8+ T cell responses as well as high-affinity neutralizing antibody. This review will aim to summarize established and new approaches that are being examined to harness the cellular immune response during respiratory viral vaccination.

Protective humoral and cellular immune responses to SARS-CoV-2 persist up to 1 year after recovery

“…Kinetics of SARS-CoV-2 specific T cell immune response. Viral-specific memory T cells can eventually lessen the disease severity by eliminating virus-infected cells 9 , forming another vital branch in combating virus infection when it occurs. To investigate whether protective T cellular immune response could persist, we generated Nucleoprotein (N) peptide pool because of its most abundant viral proteins 10 and Spike peptide pools because of their importance in viral infection and wide application 6 .…”

Rapid, robust, and sustainable antibody responses to mRNA COVID-19 vaccine in convalescent COVID-19 individuals

“…This outpatient cohort's demographics are summarized in Table 1. The median time from COVID-19 symptom onset to the outpatient visit was 47 days (IQR [43][44][45][46][47][48]. As with the hospitalized cohort, it was estimated that the time of infection was 5 days prior to date of symptom onset.…”

Infection-Acquired Versus Vaccine-Induced Immunity Against Covid-19

“…COVID-19 vaccines triggering defensive immune responses are essential for preventing related morbidity and mortality. Humoral and Th1-directed cellular reactions are particularly important for the defense [17][18][19]. While there are no specifically designed comparative studies of the infection-acquired and vaccine-induced immune responses, we can only hypothesize which type of immunity is more beneficial and safe.…”