Salivary IgA Responses Research Articles

Salivary immune responses after COVID-19 vaccination.

mRNA-based COVID-19 vaccines have played a critical role in reducing severe outcomes of COVID-19. Humoral immune responses against SARS-CoV-2 after vaccination have been extensively studied in blood; however, limited information is available on the presence and duration of SARS-CoV-2 specific antibodies in saliva and other mucosal fluids. Saliva offers a non-invasive sampling method that may also provide a better understanding of mucosal immunity at sites where the virus enters the body. Our objective was to evaluate the salivary immune response after vaccination with the COVID-19 Moderna mRNA-1273 vaccine. Two hundred three staff members of the U.S. Centers for Disease Control and Prevention were enrolled prior to receiving their first dose of the mRNA-1273 vaccine. Participants were asked to self-collect 6 saliva specimens at days 0 (prior to first dose), 14, 28 (prior to second dose), 42, and 56 using a SalivaBio saliva collection device. Saliva specimens were tested for anti-spike protein SARS-CoV-2 specific IgA and IgG enzyme immunoassays. Overall, SARS-CoV-2-specific salivary IgA titers peaked 2 weeks after each vaccine dose, followed by a sharp decrease during the following weeks. In contrast to IgA titers, IgG antibody titers increased substantially 2 weeks after the first vaccine dose, peaked 2 weeks after the second dose and persisted at an elevated level until at least 8 weeks after the first vaccine dose. Additionally, no significant differences in IgA/IgG titers were observed based on age, sex, or race/ethnicity. All participants mounted salivary IgA and IgG immune responses against SARS-CoV-2 after receiving the mRNA-1273 COVID-19 vaccine. Because of the limited follow-up time for this study, more data are needed to assess the antibody levels beyond 2 months after the first dose. Our results confirm the potential utility of saliva in assessing immune responses elicited by immunization and possibly by infection.

Serum and Salivary IgG and IgA Response After COVID-19 Messenger RNA Vaccination

There is still considerable controversy in the literature regarding the capacity of intramuscular messenger RNA (mRNA) vaccination to induce a mucosal immune response. To compare serum and salivary IgG and IgA levels among mRNA-vaccinated individuals with or without previous SARS-CoV-2 infection. In this cohort study, SARS-CoV-2-naive participants and those with previous infection were consecutively included in the CoviCompare P and CoviCompare M mRNA vaccination trials and followed up to day 180 after vaccination with either the BNT162b2 (Pfizer-BioNTech) vaccine or the mRNA-1273 (Moderna) vaccine at the beginning of the COVID-19 vaccination campaign (from February 19 to June 8, 2021) in France. Data were analyzed from October 25, 2022, to July 13, 2023. An ultrasensitive digital enzyme-linked immunosorbent assay was used for the comparison of SARS-CoV-2 spike-specific serum and salivary IgG and IgA levels. Spike-specific secretory IgA level was also quantified at selected times. A total of 427 individuals were included in 3 groups: participants with SARS-CoV-2 prior to vaccination who received 1 single dose of BNT162b2 (Pfizer-BioNTech) (n = 120) and SARS-CoV-2-naive individuals who received 2 doses of mRNA-1273 (Moderna) (n = 172) or 2 doses of BNT162b2 (Pfizer-BioNTech) (n = 135). The median age was 68 (IQR, 39-75) years, and 228 (53.4%) were men. SARS-CoV-2 spike-specific IgG saliva levels increased after 1 or 2 vaccine injections in individuals with previous infection and SARS-CoV-2-naive individuals. After vaccination, SARS-CoV-2-specific saliva IgA levels, normalized with respect to total IgA levels, were significantly higher in participants with previous infection, as compared with the most responsive mRNA-1273 (Moderna) recipients (median normalized levels, 155 × 10-5 vs 37 × 10-5 at day 29; 107 × 10-5 vs 54 × 10-5 at day 57; and 104 × 10-5 vs 70 × 10-5 at day 180 [P < .001]). In contrast, compared with day 1, spike-specific IgA levels in the BNT162b2-vaccinated SARS-CoV-2-naive group increased only at day 57 (36 × 10-5 vs 49 × 10-5 [P = .01]). Bona fide multimeric secretory IgA levels were significantly higher in individuals with previous infection compared with SARS-CoV-2-naive individuals after 2 antigenic stimulations (median optical density, 0.36 [IQR, 0.16-0.63] vs 0.16 [IQR, 0.10-0.22]; P < .001). The findings of this cohort study suggest that mRNA vaccination was associated with mucosal immunity in individuals without prior SARS-CoV-2 infection, but at much lower levels than in previously infected individuals. Further studies are needed to determine the association between specific saliva IgA levels and prevention of infection or transmission.

Salivary IgA and vimentin differentiate in vitro SARS-CoV-2 infection: A study of 290 convalescent COVID-19 patients

SARS-CoV-2 initially infects cells in the nasopharynx and oral cavity. The immune system at these mucosal sites plays a crucial role in minimizing viral transmission and infection. To develop new strategies for preventing SARS-CoV-2 infection, this study aimed to identify proteins that protect against viral infection in saliva. We collected 551 saliva samples from 290 healthcare workers who had tested positive for COVID-19, before vaccination, between June and December 2020. The samples were categorized based on their ability to block or enhance infection using in vitro assays. Mass spectrometry and enzyme-linked immunosorbent assay experiments were used to identify and measure the abundance of proteins that specifically bind to SARS-CoV-2 antigens. Immunoglobulin (Ig)A specific to SARS-CoV-2 antigens was detectable in over 83% of the convalescent saliva samples. We found that concentrations of anti-receptor-binding domain IgA >500 pg/µg total protein in saliva correlate with reduced viral infectivity in vitro. However, there is a dissociation between the salivary IgA response to SARS-CoV-2, and systemic IgG titers in convalescent COVID-19 patients. Then, using an innovative technique known as spike-baited mass spectrometry, we identified novel spike-binding proteins in saliva, most notably vimentin, which correlated with increased viral infectivity in vitro and could serve as a therapeutic target against COVID-19.

Immunogenicity of COVID-19 vaccines and their effect on HIV reservoir in older people with HIV

Older individuals and people with HIV (PWH) were prioritized for COVID-19 vaccination, yet comprehensive studies of the immunogenicity of these vaccines and their effects on HIV reservoirs are not available. Our study on 68 PWH and 23 HIV-negative participants aged 55 and older post-three vaccine doses showed equally strong anti-spike IgG responses in serum and saliva through week 48 from baseline, while PWH salivary IgA responses were low. PWH had diminished live-virus neutralization responses after two vaccine doses, which were 'rescued' post-booster. Spike-specific Tcell immunity was enhanced in PWH with normal CD4+ Tcell count, suggesting Th1 imprinting. The frequency of detectable HIV viremia increased post-vaccination, but vaccines did not affect the size of the HIV reservoir in most PWH, except those with low-level viremia. Thus, older PWH require three doses of COVID-19 vaccine for maximum protection, while individuals with unsuppressed viremia should be monitored for adverse reactions from HIV reservoirs.

Salivary IgA and IgG Antibody Responses against Periodontitis-Associated Bacteria in Crohn's Disease.

Elevated serum immunoglobulin (Ig) antibody levels are observed in Crohn's disease patients. The aim of this study was to evaluate the salivary IgA and IgG antibody levels against Porphyromonas gingivalis, Tannerella forsythia, Aggregatibacter actinomycetemcomitans, and Prevotella intermedia in Crohn's disease patients. Eighty-eight participants (47 Crohn's disease patients and 41 systemically healthy age- and gender-matched controls) were included in the study. Oral and medical health statuses were recorded and salivary samples were collected. Salivary P. gingivalis, T. forsythia, A. actinomycetemcomitans, and P. intermedia carriage were analyzed with DNA sequencing technique, salivary levels of IgG1, IgG2, IgG3, IgG4, and IgM were measured with the Luminex® xMAP™ technique, and salivary IgA and IgG antibody levels against P. gingivalis, T. forsythia, A. actinomycetemcomitans, and P. intermedia were detected by ELISA. As result, higher salivary IgG2 (p = 0.011) and IgG3 (p = 0.006), P. gingivalis IgA (p < 0.001), A. actinomycetemcomitans IgG (p = 0.001), and P. intermedia IgG (p < 0.001) antibody levels were detected in the Crohn's disease group compared to the controls. Salivary P. gingivalis carriage was lower in the Crohn's disease group in comparison to the controls (p = 0.024). In conclusion, salivary IgA antibody responses against P. gingivalis and IgG antibody responses against P. intermedia have independent associations with Crohn's disease.

Salivary and serum IgA and IgG responses to SARS-CoV-2-spike protein following SARS-CoV-2 infection and after immunization with COVID-19 vaccines.

Background: Secretory immunoglobulin A (sIgA) plays an important role in antiviral protective immunity. Although salivary testing has been used for many viral infections, including severe acute respiratory syndrome (SARS) and Middle East Respiratory Syndrome (MERS), its use has not yet been well established with the SARS coronavirus 2 (SARS-CoV-2). Quantification of salivary IgA and IgG antibodies can elucidate mucosal and systemic immune responses after natural infection or vaccination. Here, we report the development and validation of a rapid enzyme-linked immunosorbent assay (ELISA) for anti-SARS-CoV-2 salivary IgA and serum IgG antibodies, and present quantitative results for immunized subjects both prior to or following COVID-19 infections. Objective: Total and serum SARS-CoV-2 spike-specific IgG responses were compared with salivary spike-specific IgA and IgG responses in samples obtained from patients recently infected with SARS-CoV-2 and from subjects recently immunized with COVID-19 vaccines. Methods: A total of 52 paired saliva and serum samples were collected from 26 study participants: 7 subjects after COVID-19 infection and 19 subjects who were uninfected. The ELISA results from these samples were compared with five prepandemic control serum samples. Total IgG and SARS-CoV-2 spike-specific IgG in the serum samples from the subjects who were infected and vaccinated were also measured in a commercial laboratory with an enzyme immunoassay. Results: A wide variation in antibody responses was seen in salivary and serum samples measured by both methods. Three groups of serum total and IgG spike-specific SARS-CoV-2 antibody responses were observed: (1) low, (2) intermediate, and (3) high antibody responders. A correlational analysis of salivary IgA (sIgA) responses with serum IgG concentrations showed a statistical correlation in the low and intermediate antibody responder groups but not in the high group (which we believe was a result of saturation). Conclusion: These preliminary findings suggest measuring salivary and serum IgG and IgA merit further investigation as markers of current or recent SARS-CoV-2 infections.

Oral Health And Salivary Iga Responses In Division 1 Female Athletes

Oral Health And Salivary Iga Responses In Division 1 Female Athletes

Comparison of multiplex-serology and ELISA based methods in detecting HPV16 L1 antibody responses in paired saliva and serum samples of healthy men

Human papilloma viruses (HPV) are a common cause of transient infections on mucosal surfaces, also in the oral cavity. Some infections remain persistent and can, especially with high risk HPV genotypes, lead to malignancies in the oral-oropharyngeal area. Our understanding of the natural course of oral HPV infections is limited, and the local host responses are poorly known. In this study we show that anti-HPV16L1 antibodies, the IgA response being most abundant, can be measured in saliva of asymptomatic males. HPV16L1 specific multiplex serology and commercial ELISA methods were compared and also the total salivary IgA levels measured. The total salivary IgA concentrations varied from 36 to 163 μg/ml. All the assays could detect anti-HPV16 IgA from saliva, but the correlation between assays varied from non-significant 0.22 to highly significant 0.81, p < 0.01. Salivary antibody responses did not correlate with the antibody responses detected in serum (Spearman correlations between −0.12 and 0.16) not even after adjusting the specific responses to differences in total IgA in saliva. Only six of 34 individuals were HPV16 DNA positive at the time of the sampling, but interestingly, three out of four with oral HPV16 DNA had salivary anti-HPV16 IgA responses below average. In conclusion, our results show that anti-HPV16 antibodies can be measured from saliva and the salivary response differs from that of serum. Individual differences in total salivary antibody concentrations may affect also the amount of HPV16 specific antibodies in saliva. Furthermore, different assay methods showed different specificities; thus comparisons between studies must be done with care.

Salivary IgA: A biomarker for resistance to Teladorsagia circumcincta and a new estimated breeding value

Teladorsagia circumcincta is the dominant nematode of sheep in cool, temperate climates. Faecal nematode egg counts (FEC) are widely used to identify the intensity of infection and as a measure of host resistance to nematodes. However due to density-dependent effects on worm fecundity the relationship between FEC and worm burden is not linear. In addition collecting FEC data is challenging on a practical level and there is a need for more reliable markers of resistance. There are two major known mechanisms of immunity to T. circumcincta: IgE against third stage larvae (L3) and IgA against fourth stage larvae (L4), which inhibits parasite growth. In this study salivary IgA responses were measured in over 5000 animals against L3 antigen by Enzyme Linked Immunosorbent Assay (ELISA). Antigen-specific IgA levels were negatively correlated with FEC (r=−0.26, SE = 0.02) and were heritable (h2 = 0.16, SE = 0.04) indicating that they can be used to identify resistant animals suitable for inclusion in selective breeding programs. Antigen-specific IgA responses were not negatively correlated with muscle depth. Our analyses indicate that selection for T. circumcincta L3 antigen-specific IgA is possible without impacting on the production traits for the Lleyn breed.

Intensified Training Period Increases Salivary IgA Responses But Does Not Affect the Severity of Upper Respiratory Tract Infection Symptoms in Prepuberal Rhythmic Gymnasts

This study examined the effect of a 4-week intensified training (IT) period, followed by a 2-week tapering period (TP), on salivary immunoglobulin A (SIgA), salivary cortisol, and the severity of upper respiratory tract infection symptoms in 23 rhythmic gymnasts [12.1 (2.6) y; 143.9 (13.7) cm; 37.2 (9.4) kg]. Saliva sampling was conducted at pre- and post-IT, and post-TP (analyzed using enzyme-linked immunosorbent assay). The Wisconsin Upper Respiratory Symptom Survey (WURSS-21) questionnaire was completed daily to analyze the severity of upper respiratory tract infection symptoms. The session rating of the perceived exertion was used to determine the internal training load and the acute:chronic workload ratio. A higher SIgA concentration [SIgAabs (μg/mL); F = 7.6; P = .001] for post-IT [234 (104)] versus pre-IT [173 (91)], and post-TP [182 (70)], and a higher SIgA secretion rate [SIgArate (μg/min); F = 3.4; P = .04] for post-IT [69 (28)] versus pre-IT [55 (27)], and post-TP [58 (22)] were observed. No significant change was observed for cortisol (F = 0.81; P = .45) or for the severity of upper respiratory tract infection symptoms (χ2 = 2.81; P = .24). Internal training load was higher during IT (vs TP; effect size = 2.37). The acute:chronic workload for the IT weeks varied from 1.2 (0.3) to 1.4 (0.3). These results suggest that a 4-week IT may temporarily augment the oral mucosal immunity, and an acute:chronic workload of 1.2-1.4 seems to be a safe approach to periodized training loads in youth rhythmic gymnasts.

Correction to: Increased Salivary IgA Response as an Indicator of Immunocompetence After a Mindfulness and Self-Compassion-Based Intervention

Correction to: Increased Salivary IgA Response as an Indicator of Immunocompetence After a Mindfulness and Self-Compassion-Based Intervention

Increased Salivary IgA Response as an Indicator of Immunocompetence After a Mindfulness and Self-Compassion-Based Intervention

Mindfulness-based interventions (MBIs) have been consolidated in healthcare settings as a highly useful therapeutic approach. Numerous studies have demonstrated their positive influence on physical and psychological well-being. In contrast, the scientific evidence concerning the potential beneficial effects of mindfulness on biological variables such as health indicators is still scarce. Therefore, in this study, we sought to analyse the influence of a mindfulness and self-compassion-based intervention on levels of salivary immunoglobulin A (sIgA) in order to validate its use in field studies. A secondary objective of the study was to confirm the associated decline in salivary cortisol (Csal) levels and improvements in self-reported health and mood already described in the general population. For this purpose, we conducted a longitudinal design, collecting saliva samples and self-reports before and immediately after the first and the last session of the intervention. Results show an improvement in health and self-reported mood, along with an increase in the sIgA levels of participants and a reduction in Csal levels. These results reinforce existing evidence of the beneficial effects of mindfulness and self-compassion on health, evaluated from a holistic perspective, considering both biological and self-reported variables. Moreover, as already done with other biological indicators such as Csal, sIgA could be used in clinical settings to evaluate the effectiveness of MBIs.

Effects of probiotics supplementation and circuit training on immune responses among sedentary young males.

Growing evidence suggests that probiotics may have positive benefits on immune responses following endurance exercise. However, little attention has been given to its possible beneficial effects on immune responses following resistance exercise. Forty-one healthy sedentary males were recruited and randomised into four groups: sedentary control with placebo (C), probiotics (P), circuit training with placebo (Ex), and circuit training with probiotics (PEx) groups. Participants in the Ex and PEx groups performed a progressive load of circuit training at 3 times/week for 12 weeks. Each circuit comprised 10 exercises with work to rest ratio of 1:2. Participants consumed either multi-strain probiotics or placebo twice daily for 12 weeks. Body height and weight, blood pressure, resting heart rate, saliva and blood samples were collected at pre- and post-tests. Saliva flow rate and salivary IgA, α-amylase, lactoferrin and lysozyme responses were not significantly different (P>0.05) between groups and also between pre- and post-test within each group. Similarly, total leukocytes, total lymphocytes, T lymphocytes, T-helper, T-cytotoxic, B lymphocytes, and natural killer cells counts were not significantly affected (P>0.05) by the probiotics and/or circuit training. However, circuit training significantly increased (P<0.05) immune cells count at post-test as compared to pre-test. Yet, a combination of circuit training and probiotics showed no significant (P>0.05) effects on immune cells count. This study did not provide enough support for the positive effects of probiotics on immune responses among sedentary young males following resistance exercise. However, 12 weeks of circuit training enhanced immune cells count.

Rotavirus specific Salivary and Fecal IgA in Indian Children and Adults.

To compare serum, salivary and fecal IgA responses in infants and adults following rotavirus vaccination. Laboratory testing of samples from clinical trials. Medical College Hospital. 13 healthy adult volunteers not given vaccine, 20 healthy adult volunteers given one dose of bovine rotavirus tetravalent vaccine (Shantha Biotechnics), and 88 infants given 3 or 5 doses of Rotarix. Serum, salivary and fecal IgA at one or more time points. IgA antibodies were estimated in serum, saliva and fecal samples by enzyme-linked immunosorbent assay, and normalized to total IgA in saliva. In naturally infected adult volunteers, comparing serum and salivary IgA showed significant positive correlation (r=0.759; P=0.003). Of 20 vaccinated adults, complete samples showing change were available for 10; among them there was a significant positive correlation (P<0.05) between pre-vaccination serum and pre-vaccination salivary IgA but not between post-vaccination serum and post-vaccination salivary IgA. Of 88 infants given 3 or 5 doses of vaccine, 13 had more than 4-fold IgA response in serum, saliva and fecal samples, 6 had a 2-4 fold increases in all specimens. There was weak correlation between seroconversion rates measured by serum and salivary antibody responses. Salivary and stool assays were able to detect seroconversion in a few children in whom there was no detectable response in serum. Evaluation of multiple samples is useful for intensive experimental study designs and may help improve our understanding of the induction and dynamics of immune responses to rotavirus vaccination.

Vaccine-Elicited Mucosal and Systemic Antibody Responses Are Associated with Reduced Simian Immunodeficiency Viremia in Infant Rhesus Macaques.

Despite significant progress in reducing peripartum mother-to-child transmission (MTCT) of human immunodeficiency virus (HIV) with antiretroviral therapy (ART), continued access to ART throughout the breastfeeding period is still a limiting factor, and breast milk exposure to HIV accounts for up to 44% of MTCT. As abstinence from breastfeeding is not recommended, alternative means are needed to prevent MTCT of HIV. We have previously shown that oral vaccination at birth with live attenuated Mycobacterium tuberculosis strains expressing simian immunodeficiency virus (SIV) genes safely induces persistent SIV-specific cellular and humoral immune responses both systemically and at the oral and intestinal mucosa. Here, we tested the ability of oral M. tuberculosis vaccine strains expressing SIV Env and Gag proteins, followed by systemic heterologous (MVA-SIV Env/Gag/Pol) boosting, to protect neonatal macaques against oral SIV challenge. While vaccination did not protect infant macaques against oral SIV acquisition, a subset of immunized animals had significantly lower peak viremia which inversely correlated with prechallenge SIV Env-specific salivary and intestinal IgA responses and higher-avidity SIV Env-specific IgG in plasma. These controller animals also maintained CD4(+) T cell populations better and showed reduced tissue pathology compared to noncontroller animals. We show that infants vaccinated at birth can develop vaccine-induced SIV-specific IgA and IgG antibodies and cellular immune responses within weeks of life. Our data further suggest that affinity maturation of vaccine-induced plasma antibodies and induction of mucosal IgA responses at potential SIV entry sites are associated with better control of viral replication, thereby likely reducing SIV morbidity. Despite significant progress in reducing peripartum MTCT of HIV with ART, continued access to ART throughout the breastfeeding period is still a limiting factor. Breast milk exposure to HIV accounts for up to 44% of MTCT. Alternative measures, in addition to ART, are needed to achieve the goal of an AIDS-free generation. Pediatric HIV vaccines constitute a core component of such efforts. The results of our pediatric vaccine study highlight the potential importance of vaccine-elicited mucosal Env-specific IgA responses in combination with high-avidity systemic Env-specific IgG in protection against oral SIV transmission and control of viral replication in infant macaques. The induction of potent mucosal IgA antibodies by our vaccine is remarkable considering the age-dependent development of mucosal IgA responses postbirth. A deeper understanding of postnatal immune development may inform the design of improved vaccine strategies to enhance systemic and mucosal SIV/HIV antibody responses.

Development of enhanced antibody response toward dual delivery of nano-adjuvant adsorbed human Enterovirus-71 vaccine encapsulated carrier

This study introduces a new approach for enhancing immunity toward mucosal vaccines. HEV71 killed vaccine that is formulated with nanosize calcium phosphate adjuvant and encapsulated onto chitosan and alginate delivery carriers was examined for eliciting antibody responses in serum and saliva collected at weeks 0, 1, 3, 5, 7 and 9 for viral-specific IgA & IgG levels and viral neutralizing antibody titers. The antibody responses induced in rabbits by the different formulations delivered by a single (buccal) route were compared to those of dual immunization (intradermal / mucosal) and un-immunized control. Chitosan-loaded vaccine adjuvant induced elevated IgA antibody, while Alginate-adjuvant irreversible bonding sequestered the vaccine and markedly reduced immunogenicity. The induced mucosal and parenteral antibody profiles appeared in an inverse manner of enhanced mucosal IgA antibody accompanied by lower systemic IgG following a single oral immunization route. The combined intradermal and oral dual-immunized group developed an elevated salivary IgA, systemic IgG, and virus neutralizing response. A reduced salivary neutralizing antibody titer was observed and attributed to the continual secretion exchanges in saliva. Designing a successful mucosal delivery formulation needs to take into account the vaccine delivery site, dosage, adjuvant and carrier particle size, charge, and the reversibility of component interactions. The dual immunization seems superior and is a important approach for modulating the antibody response and boosting mucosal protection against HEV71 and similar pathogens based on their transmission mode, tissue tropism and shedding sites. Finally, the study has highlighted the significant role of dual immunization for simultaneous inducing and modulating the systemic and mucosal immune responses to EV71.

Salivary α-amylase and IgA responses to repeated bouts of short high-intensity exercise tests in recreationally active men

Introduction: A short high-intensity exercise test (e.g., the Wingate test) has been commonly used to measure the anaerobic power and muscle metabolism. The monitoring of salivary biomarkers in response to high intensity exercise-induced stress provides insights into the assessment of mucosal immune function. The purpose of this study was to examine the effect of repeated bouts of Wingate tests (short-duration intermittent and maximal effort exercise) on the levels of salivary α-amylase and IgA levels in male collegiate cyclists.

Salivary α-amylase and IgA responses to single versus double stepping pattern of ascending the stairs in recreationally active individuals

Salivary α-amylase and IgA responses to single versus double stepping pattern of ascending the stairs in recreationally active individuals

Salivary IgA Responses to Graded Maximal Exercise (VO2max) Testing in Healthy Adolescent Females

Salivary IgA Responses to Graded Maximal Exercise (VO2max) Testing in Healthy Adolescent Females

Salivary IgA Response and Upper Respiratory Tract Infection Symptoms During a 21-Week Competitive Season in Young Soccer Players

Sports training and competition are significant sources of stress, especially for young athletes. It is well known that physiological and psychological stressors induce neuroendocrine responses that could modulate immune system function. However, to date, little is known about the immune responses of young soccer players during a competitive season. Therefore, this study examined the effects of a 21-week competitive season divided into preseason, competitive season, and detraining on salivary immunoglobulin A (SIgA), upper respiratory tract infection (URTI) symptoms, and salivary cortisol in preadolescent male soccer players. Thirty-four young soccer players agreed to participate, and 26 (12.9 ± 0.2 years) completed the entire study. The investigation period was structured as follows: a 12-week preparatory training phase (preseason training), a 7-week competitive and a 2-week detraining phase. Resting saliva samples were taken to determine cortisol and SIgA responses. The players were required to complete a weekly log during the entire investigation reporting every sign or symptoms consistent with URTI. A significant increase in SIgA secretion rate and a decrease in URTI symptoms were observed after the 2-week detraining period (p < 0.05). No change was observed for cortisol during the study. These results indicate that training and competition demands affect the mucosal immune responses of young athletes. In addition, a short-prophylactic period (2-week detraining period) after a competitive period may attenuate mucosal immunosuppression related to URTI symptoms. Sport coaches should monitor markers of mucosal immune function to minimize illness that ultimately might lead to a decrease in performance.