Presence Of Maternal Antibodies Research Articles

Development and Evaluation of a Novel Chimeric Genotype VII Newcastle Disease Vaccine: Overcoming Maternal Antibody Interference and Spray Administration

Newcastle disease virus (NDV) poses a significant threat to the poultry industry, with the emergence of genotype VII NDV leading to extensive outbreaks and economic losses. Vaccination is the primary means of controlling NDV, but the presence of maternal antibodies (MDAs) can interfere with the immunological effect of live virus vaccines. Thus, we constructed a chimeric NDV live virus vaccine, LX-OAI4S, by replacing the extracellular regions of the F and HN genes of the NDV LX strain with the corresponding regions of the A-VII vaccine strain. The chimeric vaccine LX-OAI4S demonstrated high genetic stability, good safety, and strong reproductive capacity in chicken embryos. The LX-OAI4S vaccine induced rapid antibody production in specific pathogen-free (SPF) and commercial chickens via the intranasal and intraocular (IN/IO) routes, with hemagglutination inhibition (HI) antibody titers reaching 4.71 ± 1.03 log2 at 7 days post-vaccination (dpv), significantly higher than those of the two classical vaccine strains La Sota and VG/GA. The LX-OAI4S vaccine group provided effective protection against the challenge of genotype VII NDV virulent strain JS2/06 and inhibited viral shedding. When administered via spray, the LX-OAI4S vaccine elicited high systemic immunity against NDV in both SPF and commercial chickens, effectively protecting against clinical disease and reducing viral shedding. The chickens were exposed to high-dose vaccine for spray vaccination, and no adverse reactions were observed after vaccination. Despite the presence of anti-NDV MDAs in chickens, the NDV-specific antibody titers were significantly greater in the vaccinated groups than in the unvaccinated group. The vaccine exhibited high immunogenicity and the potential to overcome maternal antibody interference. The LX-OAI4S vaccine is a promising candidate for an ND vaccine. Its administration via spray can effectively prevent the occurrence of ND, making it a valuable tool for the poultry industry.

Current Status of Poultry Recombinant Virus Vector Vaccine Development.

Inactivated and live attenuated vaccines are the mainstays of preventing viral poultry diseases. However, the development of recombinant DNA technology in recent years has enabled the generation of recombinant virus vector vaccines, which have the advantages of preventing multiple diseases simultaneously and simplifying the vaccination schedule. More importantly, some can induce a protective immune response in the presence of maternal antibodies and offer long-term immune protection. These advantages compensate for the shortcomings of traditional vaccines. This review describes the construction and characterization of primarily poultry vaccine vectors, including fowl poxvirus (FPV), fowl adenovirus (FAdV), Newcastle disease virus (NDV), Marek's disease virus (MDV), and herpesvirus of turkey (HVT). In addition, the pathogens targeted and the immunoprotective effect of different poultry recombinant virus vector vaccines are also presented. Finally, this review discusses the challenges in developing vector vaccines and proposes strategies for improving immune efficacy.

Identifying and addressing barriers and opportunities for bovine respiratory disease complex vaccination: a consensus paper on practical recommendations for best practise vaccination.

Many questions are raised, and challenges faced in the new era of (intranasal) bovine respiratory disease complex vaccination. An increase in vaccination rate is expected, due to its positive impact on cattle health, reduction of antimicrobial use and economic factors. However, engagement of farmers and veterinarians with regard to vaccination is often affected by limitations, resulting in the development of barriers to vaccination, but also opportunities to overcome these. The objective of the report is to provide practical recommendations and a consensus on best practises for BRDC vaccination, addressing barriers faced by veterinarians and farmers. The report combines an evidence review with expert opinions and includes discussions on different vaccination approaches, such as intranasal and systemic protocols. As result of the discussions, several barriers to BRDC vaccination were identified, including a lack of knowledge or visibility of the disease's impact, the preference for blanket antibiotic use over vaccination, resistance to change, the need for visible success, uncertainty about the best time to vaccinate, and concerns about adverse reactions and vaccine efficacy in the presence of maternal antibodies. While these barriers seem substantial, they provide opportunities for the veterinary sector. Indeed, veterinarians are encouraged to use the argumentation presented, along with local case studies and diagnostic testing to highlight the impact of disease, while conducting calf health audits, ensuring expectations are managed to achieve visible success. Overall, this consensus paper aims to provide practical recommendations and support for veterinarians and farmers to overcome barriers and increase BRDC vaccination rates in cattle.

Correlates of immune protection against human rotaviruses: natural infection and vaccination.

Species A rotaviruses are the leading viral cause of acute gastroenteritis in children under 5 years of age worldwide. Despite progress in the characterization of the pathogenesis and immunology of rotavirus-induced gastroenteritis, correlates of protection (CoPs) in the course of either natural infection or vaccine-induced immunity are not fully understood. There are numerous factors such as serological responses (IgA and IgG), the presence of maternal antibodies (Abs) in breast milk, changes in the intestinal microbiome, and rotavirus structural and non-structural proteins that contribute to the outcome of the CoP. Indeed, while an intestinal IgA response and its surrogate, the serum IgA level, are suggested as the principal CoPs for oral rotavirus vaccines, the IgG level is more likely to be a CoP for parenteral non-replicating rotavirus vaccines. Integrating clinical and immunological data will be instrumental in improving rotavirus vaccine efficacy, especially in low- and middle-income countries, where vaccine efficacy is significantly lower than in high-income countries. Further knowledge on CoPs against rotavirus disease will be helpful for next-generation vaccine development. Herein, available data and literature on interacting components and proposed CoPs against human rotavirus disease are reviewed, and limitations and gaps in our knowledge in this area are discussed.

Maternally Derived Antibodies to Foot-and-Mouth Disease Virus Modulate the Antigenic Specificity of Humoral Responses in Vaccinated Cattle.

Vaccination is widely used to control foot-and-mouth disease (FMD), but maternal antibodies may interfere with the response to vaccination in calves. This study, conducted on a regularly vaccinated Malaysian dairy farm, aimed to optimise the vaccination regime by measuring the in vitro neutralising virus antibody responses of 51 calves before and after vaccination with a one or two dose vaccination regime starting at 2-7 months old. The presence of maternal antibodies was associated with poor post-vaccination antibody responses after a single dose of vaccine in calves less than 6 months old. However, a second dose of vaccine given three weeks later, improved the antibody responses in all ages of calves. This confirms the view that in regularly vaccinated farms, some combination of delay and revaccination is needed to achieve effective immunization of calves. Sera from cows and pre-vaccinated calves neutralised homologous serotype A vaccine virus more strongly than a heterologous serotype A field virus, but this pattern was reversed in some calves after vaccination. The strength of heterologous responses in calves 49 days after first vaccination correlated to the amount of transferred maternal antibody, suggesting that pre-existing antibodies could have modulated the specificity of these active antibody responses. If confirmed, such an effect by pre-existing antibodies could have wider implications for broadening the coverage of FMD vaccine responses.

DNA Vaccine Co-Expressing Hemagglutinin and IFN-γ Provides Partial Protection to Ferrets against Lethal Challenge with Canine Distemper Virus.

Canine distemper (CD), caused by canine distemper virus (CDV), is a highly contagious and lethal disease in domestic and wild carnivores. Although CDV live-attenuated vaccines have reduced the incidence of CD worldwide, low levels of protection are achieved in the presence of maternal antibodies in juvenile animals. Moreover, live-attenuated CDV vaccines may retain residual virulence in highly susceptible species and cause disease. Here, we generated several CDV DNA vaccine candidates based on the biscistronic vector (pIRES) co-expressing virus wild-type or codon-optimized hemagglutinin (H) and nucleocapsid (N) or ferret interferon (IFN)-γ, as a molecular adjuvant, respectively. Apparently, ferret (Mustela putorius furo)-specific codon optimization increased the expression of CDV H and N proteins. A ferret model of CDV was used to evaluate the protective immune response of the DNA vaccines. The results of the vaccinated ferrets showed that the DNA vaccine co-expressing the genes of codon-optimized H and ferret IFN-γ (poptiH-IRES-IFN) elicited the highest anti-CDV serum-neutralizing antibodies titer (1:14) and cytokine responses (upregulated TNF-α, IL-4, IL-2, and IFN-γ expression) after the third immunization. Following vaccination, the animals were challenged with a lethal CDV 5804Pe/H strain with a dose of 105.0 TCID50. Protective immune responses induced by the DNA vaccine alleviated clinical symptoms and pathological changes in CDV-infected ferrets. However, it cannot completely prevent virus replication and viremia in vivo as well as virus shedding due to the limited neutralizing antibody level, which eventually contributed to a survival rate of 75% (3/4) against CDV infection. Therefore, the improved strategies for the present DNA vaccines should be taken into consideration to develop more protective immunity, which includes increasing antigen expression or alternative delivery routes, such as gene gun injection.

Effect of Age and Presence of Maternal Antibodies on Success of Avian Influenza and Newcastle Disease Vaccinations in Broiler

Avian Influenza (AI) and Newcastle Disease (ND) are viral infections that attack poultry worldwide. AI outbreaks in Indonesia were first reported in 2003, which led to the death of millions of birds, while ND is an endemic disease. Vaccination control of these diseases has been carried out, but cases are still being reported in poultry. Therefore, this study aims to determine the effect of age and the presence of maternal antibodies on the success of vaccination using the AI H5N1 and the ND vaccine. It was conducted using a tiered randomized block design with 3 treatments group and 10 replicates. The tiered pattern of antibody examination was carried out at pre-vaccination, followed by 7, 14, and 21 days after vaccination. Furthermore, antibody measurements were carried out using the hemagglutination inhibition (HI) test. The results showed that age had no significant effect as demonstrated by P>0.05 on antibody titer after AI vaccination, given that the chickens at the time of vaccination had unprotected maternal antibodies. Meanwhile, age affected the ND antibody titers because the chickens with maternal protective antibodies at the time of vaccination showed lower ND antibody titers (P<0.05). AI vaccination in broilers without maternal antibodies showed a good response to antibody development, while protective maternal ND antibodies interfered with the formation of ND antibodies caused by vaccination. Based on the results, the age at vaccination and the presence of maternal antibodies greatly affects the antibody titers produced by the vaccine. Therefore, it is important to consider the timing of vaccination when maternal antibodies level decreased then vaccine should be administered to avoid neutralization.

Newcastle disease virus in poultry with an interface as a human vector

Newcastle disease (ND) is an infectious and economically important disease of poultry caused by virulent avian Paramyxovirus 1 (APMV-1). For decades, live and inactivated vaccines have been used as conventional therapy in poultry, even then failure is reported due to mismatch antigenicity, presence of maternal antibodies, cold chain disruption, and uneven vaccine applications. Many experimental vaccines have been in trial for many years, but the disease is still rampant in many parts of the world. From acute onset with high mortality to mild disease in birds, Newcastle disease virus potential as a vector has been exploited for the treatment of different cancers and vaccination of humans. The objective of this review is to understand the Newcastle disease virus, immune mechanism, prevention and control strategies adapted for the Newcastle disease in poultry, and its beneficial use as a candidate vector for human vaccines and cancer therapy.

Thrombocytopenia in an Apparently Healthy Neonate: An Unusual Report of Postnatally Acquired Dengue Infection

Dengue is one of the commonest viral infections affecting general population in endemic zones every year. However, dengue is usually not reported in newborn period as it is widely believed that infants are protected from serious viral infections in the first 6 months of life by presence of maternal antibodies. Here, a unique case of an apparently healthy newborn with dengue fever is reported where transmission of the infection occurred postnatally. A 10-day-old male child, born to a primigravida mother with normal antenatal history, presented with complaints of fever for four days along with full body macular rash. Examination findings revealed red coloured, pin-point macular rash while rest of general and systemic examination were unremarkable. Routine Sepsis work-up was negative except presence of thrombocytopenia. Keeping in mind the endemicity and season of dengue, NS1 antigen of the baby was tested by a rapid antigen test which was positive, which was further confirmed by IgM ELISA for dengue. However, the mother was asymptomatic and platelet count as well as NS1 antigen and IgM, IgG ELISA for dengue of the mother was negative.

Passive Immunisation against RHDV2 Induces Protection against Disease but Not Infection

Rabbit haemorrhagic disease virus 2 (RHDV2) is a lagovirus in the family Caliciviridae. The closely related Rabbit haemorrhagic disease virus (RHDV, termed RHDV1 throughout this manuscript for clarity) has been used extensively as a biocontrol agent in Australia since the mid-1990s to manage wild rabbit populations, a major economic and environmental pest species. Releasing RHDV1 into populations with a high proportion of rabbits less than 8–10 weeks of age leads to non-lethal infection in many of these young animals, with subsequent seroconversion and long-term immunity against reinfection. In contrast, RHDV2 causes lethal disease even in young rabbits, potentially offering substantial benefits for rabbit management programs over RHDV1. However, it is not clear how acquired resistance from maternal antibodies may influence immunity after RHDV2 infection. In this study, we assessed serological responses after RHDV2 challenge in young rabbits of three different ages (5-, 7-, or 9-weeks-old) that were passively immunised with either high- (titre of 2560 by RHDV IgG ELISA; 2.41 mg/mL total protein) or low- (titre of 160–640 by RHDV IgG ELISA; 1.41 mg/mL total protein) dose RHDV2 IgG to simulate maternal antibodies. All rabbits treated with a high dose and 75% of those treated with a low dose of RHDV2 IgG survived virus challenge. Surviving animals developed robust lagovirus-specific IgA, IgM, and IgG responses within 10 days post infection. These findings demonstrate that the protection against RHDV2 conferred by passive immunisation is not sterilising. Correspondingly, this suggests that the presence of maternal antibodies in wild rabbit populations may impede the effectiveness of RHDV2 as a biocontrol.

Pertussis Immunization During Pregnancy: Assessment of the Role of Maternal Antibodies on Immune Responses in Term and Preterm-Born Infants.

Limited data exist on the impact of maternal tetanus, diphtheria, acellular pertussis (Tdap) vaccination for preterm born infants. We report its effect at birth and on antibody-mediated immune responses to a DTaP-IPV-HB-PRP~T vaccine in preterm compared with term infants. Women delivering at term or prematurely were either vaccinated with a Tdap vaccine (Boostrix; GSK) during pregnancy or not vaccinated in the last 5 years. Cord and maternal blood were collected at delivery. Infants were vaccinated with DTaP-IPV-HB-PRP~T vaccine (Hexyon; Sanofi Pasteur) and blood collected before and 1 month after primary (8-12-16 weeks) and before and 1 month after booster vaccination (13 or 15 months for preterm and term, respectively). Immunoglobulin G antibodies against all antigens included in DTaP-IPV-HB-PRP~T vaccine were measured (NCT02511327). Cord blood geometric mean concentrations (GMCs) in preterm infants from Tdap-vaccinated women were significantly higher than in term and preterm infants from unvaccinated women. A longer time interval between maternal vaccination and delivery resulted in higher cord blood GMCs in preterm infants. Equal GMCs in term and preterm infants from Tdap-vaccinated women were observed after primary vaccination. After boosting, significantly lower GMCs were seen for pertussis toxin, filamentous hemagglutinin, and tetanus toxoid in preterm compared with term infants from Tdap-vaccinated women, yet still comparable to GMCs in both term and preterm infants from unvaccinated women. Preterm infants profit from maternal Tdap vaccination. Prematurity did not influence primary immune responses in the presence of maternal antibodies but was associated with a lower booster immune response.

Presence of maternal antibody at initial respiratory syncytial virus (RSV) infection shapes innate and adaptive responses following repeat RSV exposure

Abstract RSV is the leading cause of childhood hospitalization due to bronchiolitis and a significant risk factor for the development of allergic airway responses. Maternal vaccination has emerged as a promising strategy to protect infants against severe disease. However, the presence of maternal antibody (matAb) at primary RSV infection has been linked to development of wheeze later in life. Therefore, we sought to understand how high levels of matAb during early life RSV infection shapes innate and adaptive immune responses on repeat RSV exposure. Using a murine model of maternal vaccination, we assessed immune responses following adult RSV re-challenge of infants born to unvaccinated and RSV preF-vaccinated dams. Presence of matAb at primary RSV infection resulted in differential activation of resident lung populations at 4 days post-secondary infection (DPSI). Specifically, proliferation of IL-5+ and IL-13+ type 2 innate lymphoid cells were increased in association with elevated numbers of eosinophils in the alveolar space. At 8 DPSI, IL-4-, IL-5-, and IL-13-producing, but not IFNγ-producing, CD4+ T cells were significantly increased, indicating a dominant Th2 response in mice born to vaccinated dams. Importantly, lung inflammation and mucus production were similarly elevated in mice born to immunized and unimmunized dams, suggesting that maternal vaccination did not prevent pathology on repeat infection. Taken together, these data demonstrate that the presence of matAb at primary RSV infection differentially alters innate and adaptive immune responses on secondary RSV exposure. Understanding the mechanisms that drive differential cell activation in the presence of matAb will guide future maternal immunization strategies.

NASYM, a live intranasal vaccine, protects young calves from bovine respiratory syncytial virus in the presence of maternal antibodies.

Bovine respiratory syncytial virus (BRSV) is a major problem for cattle worldwide during their first year of life. The aim of the present study was to evaluate efficacy and longevity of immunity of a live vaccine (NASYM, HIPRA) in the presence of maternally derived antibodies (MDA). Calves (36) were distributed in four groups, based on MDA status and treatment. They received NASYM or a placebo at an early age (less than two weeks) by intranasal route. Eight weeks later, animals were challenged with the Asquith strain of BRSV. Efficacy was assessed by monitoring clinical signs and mortality, PaO2 , virus shedding and lung lesions. The immunological response was evaluated by measuring IgG in serum and IgA in nasal secretions. A reduction of mortality, lung lesions, shedding and a higher PaO2 was achieved in NASYM vaccinated groups, independently of MDA status. An anamnestic IgG response was observed after challenge in vaccinated animals, both in MDA+ and MDA- groups. An IgA response was also observed in vaccinated animals after vaccination and challenge. NASYM protected newborn calves with MDAs during the first 10 weeks of life, against a very virulent challenge that caused extensive pulmonary lesions and deaths in control animals, with just a single intranasal dose.

Evaluation of antigenic load in pregnant sows and identification of isoimmunization markers in offspring to increase productive and reproductive indicators for obtaining biologically safe organic products

Immunological aspects of the relationship in the functional system “mother-fetus” are consciously important both in the scientific and practical direction of the life of living organisms. The formation of the main parameters of isoimmunization is an equivalent aspect in relation to the basics of the formation of artificial tolerance mechanisms. Changes in immunological reactivity to viral and bacterial antigens may cause increased susceptibility to infectious diseases. Different levels of this condition in newborn and adult animal organisms should be based on the fact that the fetus and newborn after birth first comes into contact with the antigen, while the adult body already has partial sensitization. Chronic carrier of pathogens in animals and their influence on the spread of the infectious process is an urgent problem of modern veterinary medicine. The possibility of vaccination in newborns is limited by the presence of maternal antibodies that have an immunosuppressive effect.The immunological relationship between the fetal mother’s body in a non-inbred population should be considered in two aspects: the effects caused by maternal antigens in the fetus; the effect of fetal antigens on the mother’s body. Level of functional reserves of the pregnant body is important in the prevention of intrauterine infection.

Congenital malaria due to <em>Plasmodium vivax</em> infection in a neonate

Introduction: Congenital malaria occurs through vertical transmission of parasites from mother during pregnancy/perinatally during labour. Presence of maternal antibody may delay symptoms upto 3-6 weeks after birth.Case Representation: A 21days neonate presented with not accepting feed, excessive crying, fever since 2days. On examination baby was pale, lethargic, febrile, hepatosplenomegaly+. Peripheral smear-rings & trophozoits of P. vivax, diagnosed as congenital malaria with neonatal sepsis. IV. Ceftriaxone, IV. Amikacin started. Chloroquine was given.Discussion: This case shows importance of considering congenital malaria as differential diagnosis of neonatal sepsis in neonates with history of malaria during pregnancy. Mechanisms for congenital transmission of malaria include maternal transfusion into fetal circulation at delivery/during pregnancy. Sometimes mother might had mild episode malarial during the 9th month of pregnancy, resolved spontaneously, and remained undiagnosed. The time of onset of symptoms in congenital malaria can vary from immediately after birth to few weeks. The drug of choice for congenital malaria remains chloroquine.

In Vivo Demonstration of the Superior Replication and Infectivity of Genotype 2.1 with Respect to Genotype 3.4 of Classical Swine Fever Virus by Dual Infections.

In Taiwan, the prevalent CSFV population has shifted from the historical genotype 3.4 (94.4 strain) to the newly invading genotype 2.1 (TD/96 strain) since 1996. This study analyzed the competition between these two virus genotypes in dual infection pigs with equal and different virus populations and with maternally derived neutralizing antibodies induced by a third genotype of modified live vaccine (MLV), to simulate that occurring in natural situations in the field. Experimentally, under various dual infection conditions, with or without the presence of maternal antibodies, with various specimens from blood, oral and fecal swabs, and internal organs at various time points, the TD/96 had consistently 1.51−3.08 log higher loads than those of 94.4. A second passage of competition in the same animals further widened the lead of TD/96 as indicated by viral loads. The maternally derived antibodies provided partial protection to both wild type CSFVs and was correlated with lower clinical scores, febrile reaction, and animal mortality. In the presence of maternal antibodies, pigs could be infected by both wild type CSFVs, with TD/96 dominating. These findings partially explain the CSFV shift observed, furthering our understanding of CSFV pathogenesis in the field, and are helpful for the control of CSF.

Effect of Parenteral Vaccination of Newborn Holstein Calves against Viral Agents Involved in Bovine Respiratory Disease (BRD)

Background: Newborn calves are born immunosuppressed, hypogammaglobulinemic, immunologically immature, and therefore more vulnerable to many infectious diseases. During pregnancy, the fetal-placental environment is regulated by Th2-type cytokines that neutralize Th1 responses, an important factor for immune defense against viral agents. The ingestion and absorption of colostral immunoglobulins enhance the immunity of the neonate. However, the presence of maternal antibodies might negatively affect the success of parental vaccination in the first two months of life. This study aimed to evaluate the effecacy of parenteral vaccination in newborn calves with high titers of maternal antibodies against respiratory viruses.Materials, Methods & Results: Twenty-eight Holstein calves were allocated to the vaccinated group (VAC, n = 18) or an unvaccinated control group (NVAC, n = 10). The initial vaccination with 5 mL of a commercial vaccine occurred around the 14th day of life (D14) and the booster at D35. Respiratory and diarrhea symptoms were evaluated at D12, D14, D16, D20, D31, D36, D45, D53, and D60. Blood samples were taken for leukogram, haptoglobin, and seroneutralization of BVDV, BoHV-1, BRSV, and BPI3V, at the time of vaccination at D14 (T1), at booster (D35, T2), and 21 days after the booster (D56, T3). Despite the increased prevalence of BRD during the period of the study, no calves from either group exhibited respiratory disease at D12 or D14. In subsequent assessments, the frequency of BRD increased over time in the VAC group until it reached a maximum prevalence of 38.9% (7/18) at D31. In the NVAC group, the maximum prevalence observed was 40% at D45 and D60. A comparison of the frequencies for BRD cases showed a statistical trend at D36 (P = 0.07), with a higher prevalence for the NVAC group (30%) in relation to the VAC group (5.6%). For the NVAC group, a greater number of total leukocytes was observed at T3 (P = 0.038) and granulocytes (trend) at T2 (P = 0.066). Time analysis demonstrated a decrease in haptoglobin concentration in both groups (NVAC, P = 0.005 and VAC, P = 0.006), with a reduction in the values at T1 and T3 (NVAC = 0.005 and VAC = 0.024). Antibody titers were similar between groups for BVDV, BoHV-1, and BRSV. Higher titers for BPI3V were observed for the VAC group at D56 (P = 0.045).Discussion: The early-onset BRD was present in both groups between 30 and 60 days of age, based on the higher prevalence observed. These data reinforce the importance of early immunization programmes before infection. Factors such as management practices and facilities may have also contributed to the higher prevalence of BRD. The increased number of leukocytes and neutrophils at T2 (D35) and T3 (D56) in the NVAC group points to a stronger inflammatory response to various types of potential challenges. The inflammatory leukocyte profile explains the higher haptoglobin values observed in the NVAC group at T2 (D35). The similarity of titers of antibodies against BVDV, BoHV-1, and BRSV between groups may indicate that vaccinating the calves at 14 days of age did not induce a humoral immune response to these viruses, likely due to interference from the maternal antibodies. Early vaccination prevented a drop in specific viral antibodies and promoted partial protection for vaccinated calves around 14 days of age, with a decrease in the intensity of the inflammatory response at the peak of the disease and a higher concentration of antibodies against BPI3V after the booster.

Specific immunological areactivity formation during gestation period in pregnant sows

Changes in immunological reactivity to viral and bacterial antigens may cause increased susceptibility to infectious diseases. Different levels of this condition in newborn and adult animal organisms should be based on the fact that the fetus and newborn after birth first comes into contact with the antigen, while the adult body already has partial sensitization. Chronic carrier of pathogens in animals and their influence on the spread of the infectious process is an urgent problem of modern veterinary medicine. The possibility of vaccination in newborns is limited by the presence of maternal antibodies that have an immunosuppressive effect. A high level of functional reserves of the pregnant body is important in the prevention of intrauterine infection. On the one hand, infection in the prenatal period of development affects the processes of growth and development of the fetus, on the other hand, during this period, the mother's body is isoimmunized by fetal antigens, accompanied by increased sensitivity of the body with the predominant manifestation of cellular phenomena in the absence of enhanced antibody synthesis.

ФОРМИРОВАНИЕ СПЕЦИФИЧЕСКОЙ ИММУНОЛОГИЧЕСКОЙ АРЕАКТИВНОСТИ В ПЕРИОД БЕРЕМЕННОСТИ У СУПОРОСНЫХ СВИНОМАТОК

Changes of immunological reactivity to viral and bacterial antigens can cause in-creased susceptibility to infectious diseases. Different levels of this changes in newborn and adult animal organisms should be based on the fetus and newborn reactivity, first coming into contact with the antigen after birth, whereas the adult organism already has partial sensitization. Chronic vectors of pathological agents in animals and their in-fluence on the spread of infectious process is a persisting problem of modern veterinary medicine. The ability to use vaccination in newborns is limited by the presence of maternal antibodies that have immunosuppres-sive effects. High level of functional abilities of preg-nant organism is important in prevention of intrauterine infection. Infection in the prena-tal period of development affects fetal growth and development processes on the one hand, and on the other - isoimmuniza-tion of the maternal organism with fetal anti-gens occurs, accompanied by increased sen-sitivity of the organism with predominant manifestation of cellular phenomena, in the absence of increased synthesis of antibodies. Given the high importance of the functional reserves of the newborn organism, the intra-uterine development and completeness of the placental barrier are important. Detection of the transportation of infectious agent in inac-tive phase during pregnancy of different gestational period should be considered from the point of view of avidity and seropositivi-ty of pregnant animals. The high variety of clinical manifesta-tions of intrauterine infection requires the development of minimally invasive methods of antenatal and intranatal prediction, which allow at the stage of pregnancy and/or child-birth to assess the presence of an agent in a very small amount as the risk of the future development of infectious disease of the fetus and newborn, or complications of the early neonatal period.

Respiratory Syncytial Virus Vaccines: Are We Making Progress?

Respiratory Syncytial Virus Vaccines: Are We Making Progress?