Intranasal Route Of Immunization Research Articles

The impact of primary immunization route on the outcome of infection with SARS-CoV-2 in a hamster model of COVID-19.

The COVID-19 pandemic, caused by the SARS-CoV-2 virus, has resulted in over 6.7 million deaths worldwide. COVID-19 vaccines administered parenterally via intramuscular or subcutaneous (SC) routes have reduced the severity of respiratory infections, hospitalization rates, and overall mortality. However, there is a growing interest in developing mucosally delivered vaccines to further enhance the ease and durability of vaccination. This study compared the immune response in hamsters immunized with live SARS-CoV-2 virus via SC or intranasal (IN) routes and assessed the outcome of a subsequent IN SARS-CoV-2 challenge. Results showed that SC-immunized hamsters elicited a dose-dependent neutralizing antibody response but of a significantly lower magnitude than that observed in IN-immunized hamsters. The IN challenge with SARS-CoV-2 in SC-immunized hamsters resulted in body weight loss, increased viral load, and lung pathology than that observed in IN-immunized and IN-challenged counterparts. These results demonstrate that while SC immunization renders some degree of protection, IN immunization induces a stronger immune response and better protection against respiratory SARS-CoV-2 infection. Overall, this study provides evidence that the route of primary immunization plays a critical role in determining the severity of a subsequent respiratory infection caused by SARS-CoV-2. Furthermore, the findings suggest that IN route of immunization may be a more effective option for COVID-19 vaccines than the currently used parenteral routes. Understanding the immune response to SARS-CoV-2 elicited via different immunization routes may help guide more effective and long-lasting vaccination strategies.

Nasal vaccine as a booster shot: a viable solution to restrict pandemic?

The coronavirus disease 2019 (COVID-19) pandemic revolutionized the vaccine market and initiated the momentum for alternative routes of administration for vaccines. The intranasal route of immunization is one such possibility that appears to be the most promising since it has some significant advantages, particularly in the prevention of respiratory infection. To analyze and summarize the role of nasal vaccines over conventional vaccines during COVID-19 and the need for the nasal vaccine as a booster shot. In this narrative review, the required data was retrieved using keywords “COVID-19,” “Intranasal,” “Immunity,” “Nasal spray,” and “Mucosal” in databases including PubMed, Scopus, Embase, Science Direct, and Web of Sciences. The results of the study showed that the nasal vaccines were both effective and protective according to the current researches approaching during the COVID-19 period and the preclinical and clinical phase trials prove the intranasal vaccination elicits more robust and cross-protective immunity than conventional vaccines. In this narrative review article, mechanisms across the nasal mucosa will be briefly presented and the current status of nasal vaccines during the COVID-19 pandemic is summarized, and advantages over traditional vaccines are provided. Furthermore, after exploring the primary benefits and kinetics of nasal vaccine, the potential for consideration of nasal vaccine as a booster dose is also discussed.

Intranasal immunization with coxsackievirus A16 virus-like particles confers protection against lethal infection in neonatal mice.

Coxsackievirus A16 (CV-A16) is one of the main causative agents of hand, foot and mouth disease (HFMD) in young children and has become prevalent in the Asia-Pacific region in recent years. However, no approved vaccines or drugs are available for CV-A16 infection. CV-A16 virus-like particles (VLPs) are a potential vaccine candidate; however, whether the intranasal route of immunization is suitable for inducing immune responses against CV-A16 infection has not been clarified. In this study, the comprehensive immunogenicity and protective efficacy of the CV-A16 VLP vaccine were evaluated by multiple methods in a mouse model. In mice, a high neutralizing antibody (NTAb) titre could be elicited by intranasal immunization with CV-A16 VLPs, which produced NTAb levels similar to those induced by intranasal immunization with inactivated CV-A16. Passive immunity with NTAbs provided very good protection, as the survival rate of the immunized neonatal mice was 100% after challenges with CV-A16 at a dose of 1000 LD50. Passive protective effects were transferred to the neonates via the mother, thus protecting all the pups against challenges with the homologous or heterologous strains of CV-A16 at a dose of 1000 LD50. In addition, intranasal immunization with CV-A16 VLPs also induced the production of mucosal secretory IgA (s-IgA) antibodies, which may inhibit CV-A16 virus invasion. This study provides valuable supplemental information to facilitate our understanding of the specific protective efficacy of CV-A16 VLPs and has significance for development of the candidate vaccine into a safe and effective vaccine.

Intramuscular and intranasal immunization with an H7N9 influenza virus-like particle vaccine protects mice against lethal influenza virus challenge

The H7N9 influenza virus epidemic has been associated with a high mortality rate in China. Therefore, to prevent the H7N9 virus from causing further damage, developing a safe and effective vaccine is necessary. In this study, a vaccine candidate consisting of virus-like particles (VLPs) based on H7N9 A/Shanghai/2/2013 and containing hemagglutinin (HA), neuraminidase (NA), and matrix protein (M1) was successfully produced using a baculovirus (BV) expression system. Immunization experiments showed that strong humoral and cellular immune responses could be induced by the developed VLPs when administered via either the intramuscular (IM) or intranasal (IN) immunization routes. Notably, VLPs administered via both immunization routes provided 100% protection against lethal infection caused by the H7N9 virus. The IN immunization with 40μg of H7N9 VLPs induced strong lung IgA and lung tissue resident memory (TRM) cell-mediated local immune responses. These results provide evidence for the development of an effective preventive vaccine against the H7N9 virus based on VLPs administered through both the IM and IN immunization routes.

A viable recombinant rhabdovirus lacking its glycoprotein gene and expressing influenza virus hemagglutinin and neuraminidase is a potent influenza vaccine.

The emergence of novel influenza viruses that cause devastating human disease is an ongoing threat and serves as an impetus for the continued development of novel approaches to influenza vaccines. Influenza vaccine development has traditionally focused on producing humoral and/or cell-mediated immunity, often against the viral surface glycoproteins hemagglutinin (HA) and neuraminidase (NA). Here, we describe a new vaccine candidate that utilizes a replication-defective vesicular stomatitis virus (VSV) vector backbone that lacks the native G surface glycoprotein gene (VSVΔG). The expression of the H5 HA of an H5N1 highly pathogenic avian influenza virus (HPAIV), A/Vietnam/1203/04 (VN1203), and the NA of the mouse-adapted H1N1 influenza virus A/Puerto Rico/8/34 (PR8) in the VSVΔG vector restored the ability of the recombinant virus to replicate in cell culture, without the requirement for the addition of trypsin. We show here that this recombinant virus vaccine candidate was nonpathogenic in mice when given by either the intramuscular or intranasal route of immunization and that the in vivo replication of VSVΔG-H5N1 is profoundly attenuated. This recombinant virus also provided protection against lethal H5N1 infection after a single dose. This novel approach to vaccination against HPAIVs may be widely applicable to other emerging strains of influenza virus. Preparation for a potentially catastrophic influenza pandemic requires novel influenza vaccines that are safe, can be produced and administered quickly, and are effective, both soon after administration and for a long duration. We have created a new influenza vaccine that utilizes an attenuated vesicular stomatitis virus (VSV) vector, to deliver and express influenza virus proteins against which vaccinated animals develop potent antibody responses. The influenza virus hemagglutinin and neuraminidase proteins, expressed on the surface of VSV particles, allowed this vaccine to grow in cell culture and induced a potent antibody response in mice that was effective against infection with a lethal influenza virus. The mice showed no adverse reactions to the vaccine, and they were protected against an otherwise lethal influenza infection after only 14 days postvaccination and after as many as 140 days postvaccination. The ability to rapidly produce this safe and effective vaccine in cell culture is additionally advantageous.

Canine zona pellucida glycoprotein-3: Up-scaled production, immunization strategy and its outcome on fertility

Zona pellucida (ZP) glycoproteins based contraceptive vaccines have been proposed for the management of wildlife population. In the present study, a fusion protein encompassing promiscuous T cell epitope of tetanus toxoid [TT; amino acid (aa) residues 830–844] followed by a dilysine linker and an ectodomain of dog ZP3 (ZP3; aa residues 23–348) without any affinity tag (TT-KK-ZP3) has been expressed in Escherichia coli. The recombinant protein was successfully produced in fed-batch fermentor and purified. The average yield of purified refolded protein was 12.20±0.61mg/2g wet cell pellet. Female FvB/J mice immunized with the varying doses of recombinant TT-KK-ZP3 supplemented with alum/PetGel A as adjuvants following a three injection schedule, showed dose dependent increase in serum IgG titer. Antibodies against TT-KK-ZP3 recognized native mouse/dog ZP and significantly inhibited mouse in-vitro fertilization (p=0.012). Immunized mice showed significant reduction in fertility (p<0.05). Higher antibody titers were associated with a decrease in the number of pups born to the immunized female mice. To reduce the number of injections, two injection schedule using various dose combinations of TT-KK-ZP3 supplemented with alum revealed lower immunogenicity and contraceptive efficacy as compared to the three injection schedule. To overcome this, CpG motif was included in addition to alum and both intraperitoneal and intranasal route of immunization following the two injection schedule was investigated. Inclusion of CpG significantly enhanced the antibody titer and improved contraceptive efficacy. In the mice immunized following intraperitoneal route, serum/vaginal IgG and in the mice immunized through intranasal route, vaginal IgA seemed to be important for curtailment in fertility. To conclude, the recombinant protein described herein may be a good candidate for developing contraceptive vaccine for the wildlife population management, in particular street dogs.

Induction of pulmonary mucosal immune responses with a protein vaccine targeted to the DEC-205/CD205 receptor

It is of great interest to develop a pneumonic plague vaccine that would induce combined humoral and cellular immunity in the lung. Here we investigate a novel approach based on targeting of dendritic cells using the DEC-205/CD205 receptor (DEC) via the intranasal route as way to improve mucosal cellular immunity to the vaccine. Intranasal administration of Yersinia pestis LcrV (V) protein fused to anti-DEC antibody together with poly IC as an adjuvant induced high frequencies of IFN-γ secreting CD4+ T cells in the airway and lung as well as pulmonary IgG and IgA antibodies. Anti-DEC:LcrV was more efficient to induce IFN-γ/TNF-α/IL-2 secreting polyfunctional CD4+ T cells when compared to non-targeted soluble protein vaccine. In addition, the intranasal route of immunization with anti-DEC:LcrV was associated with improved survival upon pulmonary challenge with the virulent CO92 Y. pestis. Taken together, these data indicate that targeting dendritic cells via the mucosal route is a potential new avenue for the development of a mucosal vaccine against pneumonic plague.

Cell-mediated immune response to epitopic MAP (multiple antigen peptide) construct of LcrV antigen of Yersinia pestis in murine model

Yersinia pestis is the causative agent of plague. Cellular immunity seems to play an important role in defense against this disease. The subunit vaccine based on V (Lcr V) antigen has been proved to be immunogenic in animals and in humans. The multiple antigen peptide (MAP), incorporating all the relevant B and T cell epitopes is highly immunogenic in mice through intranasal route of immunization in PLGA particles containing CpG-ODN as an immunoadjuvant inducing humoral and mucosal immune response. In the present study, cell-mediated immune response using same MAP was studied in murine model. Primary and memory T cell responses were studied in outbred and inbred mice immunized intranasally with MAP in the presence of two immunoadjuvants (Murabutide and CpG-ODN). All the three compartments (Spleen, Lamina propria and Peyer’s patches) of the lymphoid system showed increased lymphoproliferative response. Highest lymphoproliferative response was observed especially with CpG-ODN. Cytokine profile in the culture supernatant showed highest Th1 and Th17 levels. FACS analysis showed expansion of both CD4+ and CD8+ T cells producing gamma-interferon, perforin and granzyme-B with major contribution from CD4+ T cells.

One time intranasal vaccination with a modified vaccinia Tiantan strain MVTT ZCI protects animals against pathogenic viral challenge

To combat variola virus in bioterrorist attacks, it is desirable to develop a noninvasive vaccine. Based on the vaccinia Tiantan (VTT) strain, which was historically used to eradicate the smallpox in China, we generated a modified VTT (MVTT ZCI) by removing the hemagglutinin gene and an 11,944 bp genomic region from HindIII fragment C2L to F3L. MVTT ZCI was characterized for its host cell range in vitro and preclinical safety and efficacy profiles in mice. Despite replication-competency in some cell lines, unlike VTT, MVTT ZCI did not cause death after intracranial injection or body weight loss after intranasal inoculation. MVTT ZCI did not replicate in mouse brain and was safe in immunodeficient mice. MVTT ZCI induced neutralizing antibodies via the intranasal route of immunization. One time intranasal immunization protected animals from the challenge of the pathogenic vaccinia WR strain. This study established proof-of-concept that the attenuated replicating MVTT ZCI may serve as a safe noninvasive smallpox vaccine candidate.

Induction of mucosal and systemic humoral immune responses in murine system by intranasal immunization with peptide antigens of P. vivax and CpG oligodeoxynucleotide (ODN) in microparticle delivery

In the present study we have investigated the immunomodulatory effects of two adjuvants, CpG 1826 (two copies of CpG motifs) and CpG 2006 (three copies of CpG motifs) to the five peptide antigens of Plasmodium vivax derived from circumsporozoite protein (CSP), merozoite surface protein-1 (MSP1#1, MSP1#23), apical membrane antigen-1 (AMA-1) and gametocyte surface antigen (Pvs24) in alum and microparticle formulations, using intramuscular and intranasal routes of immunization. Alum formulation without CpG ODN generated low serum IgG and IgA antibody titers and the predominant IgG isotypes were IgG1 but with the addition of CpG ODN (1826 or 2006), the antibody titers were increased by four fold with the predominance of IgG2a/2b isotypes. The SIgA peak titers in lung and intestinal washes were significantly increased with the intranasal mode of administration. Specific activity measurement was done to calculate for the accurate amounts of total serum IgG, IgA and SIgA in washes and showed direct correlation between antibody titer and its concentration. High titer anti-Pvs24 antibodies have significant inhibitory effects on parasite development in the mosquito midgut when tested in membrane feeding assays. The immunofluorescence results show that the peptide specific antisera reacted with the air-dried parasite antigens isolated from P. vivax patients. The present study demonstrates that intranasal route of immunization appears to be an alternate mode of inducing protective immunity in P. vivax malaria.

Immunization with Vibrio cholerae Outer Membrane Vesicles Induces Protective Immunity in Mice

The gram-negative bacterium Vibrio cholerae releases outer membrane vesicles (OMVs) during growth. In this study, we immunized female mice by the intranasal, intragastric, or intraperitoneal route with purified OMVs derived from V. cholerae. Independent of the route of immunization, mice induced specific, high-titer immune responses of similar levels against a variety of antigens present in the OMVs. After the last immunization, the half-maximum total immunoglobulin titer was stable over a 3-month period, indicating that the immune response was long lasting. The induction of specific isotypes, however, was dependent on the immunization route. Immunoglobulin A, for example, was induced to a significant level only by mucosal immunization, with the intranasal route generating the highest titers. We challenged the offspring of immunized female mice with V. cholerae via the oral route in two consecutive periods, approximately 30 and 95 days after the last immunization. Regardless of the route of immunization, the offspring was protected against colonization with V. cholerae in both challenge periods. Our results show that mucosal immunizations via both routes with OMVs derived from V. cholerae induce long-term protective immune responses against this gastrointestinal pathogen. These findings may contribute to the development of "nonliving," OMV-based vaccines against V. cholerae and other enteric pathogens, using the oral or intranasal route of immunization.

Induction of cellular immune responses to simian immunodeficiency virus gag by two recombinant negative-strand RNA virus vectors.

A recombinant Newcastle disease virus (rNDV) expressing simian immunodeficiency virus (SIV) Gag protein (rNDV/SIVgag) was generated. The rNDV/SIVgag virus induced Gag-specific cellular immune responses in mice, leading to a specific anti-Gag antiviral immunity. This was evidenced by the inhibition of growth of recombinant vaccinia virus expressing an identical Gag antigen (rVac/SIVgag) but not of wild-type vaccinia virus in rNDV/SIVgag-immunized mice. Among intravenous, intraperitoneal, or intranasal immunization routes, intranasal administration induced the strongest protective response against challenge with rVac/SIVgag. We further demonstrated that these immune responses were greatly enhanced after booster immunization with recombinant influenza viruses expressing immunogenic portions of SIV Gag. The magnitude of the protective immune response correlated with the levels of cellular immune responses to Gag, which were still evident 9 weeks after immunization. These results suggest that rNDV and influenza virus vectors are suitable candidate vaccines against AIDS as well as against other infectious diseases.

Local and Systemic Opsonic Adherent, Hemagglutinating and Rosette Forming Activity in Mice induced by Respiratory Immunization with Sheep Red Blood Cells

The humoral response in mice after intranasal (IN) instillation of sheep red blood cells (SRBC) was compared to that produced by intraperitoneal route of immunization. Study of opsonic adherent (passive indirect cytophilic) and hemagglutinating antibody levels in serum and bronchial washings after repeated challenge with SRBC showed that serum antibody titers following respiratory immunization does not differ from the general patterns of a humoral antibody response. The bronchial wash antibody titer was higher than the serum titer as calculated per globulin unit. In contrast, the appearance of measurable antibodies in the bronchial washings after repeated intraperitoneal immunization was delayed and in low titer. B. pertussis vaccine administered in conjunction with SRBC was found to be an excellent adjuvant in the intranasal route of immunization. A single administration of SRBC-Pertussis evoked a considerable adjuvant effect as measured by hemagglutinating and opsonic adherent tests. Monospecific anti-mouse IgG nullified the hemagglutinating and opsonic adherent activity of the bronchial washings, while monospecific anti-mouse IgM had no effect in either activity.Lung and spleen cells capable of forming rosettes with SRBC of intranasally immunized and control mice were counted. Mean response on day 14 was 6 × 103 rosettes per million lung lymphoid cells in comparison with less than 103 in control mice. No difference was found in the number of rosette-forming cells in the spleen of control and intranasally immunized mice.

Immunologic responses of atopic and normal individuals to aerosolized dextran

The immunologic response of atopic and normal subjects to an intranasally administered polysaccharide antigen was determined by exposing groups of these individuals to a native dextran at weekly intervals for five months. A pattern of immediate skin reactivity appeared with greater frequency early in the atopic aerosolized group. Almost all subjects regardless of group had small amounts of antibody to dextran prior to intranasal exposure as determined by the bentonite flocculation technique and titers showed a modest increase during the course of immunization. Although the bentonite flocculating antibody appeared to be non-identical with skin-sensitizing antibody, there was a rough correlation between degree of wheal-and-erythema skin reactivity and flocculating antibody in any single subject irrespective of group. These results are similar to those obtained using an aerosolized protein antigen and suggest that the intranasal route of immunization is sufficient for sensitization of atopic as opposed to normal individuals. They further suggest either latent quantitative differences in the immune apparatus of atopic and normal subjects which become manifest by using the intranasal route of immunization or else an enhanced mucosal permeability to inhalant antigens resulting in greater absorption of airborne protein and polysaccharide antigens in such individuals.