The Safety and Efficacy Evaluation of PRRS Attenuated Vaccine BG895 Strain in Experimental Pigs

From the PRRSV virulent strain BG8 isolated from a PRRSV-infected pig, using serial passage method in MARC-145 cell line, we have successfully obtained an attenuated strain in 95th passage, named as BG895, with high potential to be a vaccine candidate. In this study, we present the results of the safety and efficacy evaluation of BG895 against PRRSV in experimental pigs. Trial results of vaccine formula using strain BG895 have very high safety when inoculating 5 doses/animal and 10 doses/animal. Evaluation of immune response by ELISA method showed that, from 14 days post inoculation, anti-PRRSV antibodies were detected in the serum of all inoculated pigs in vaccine batches with the lowest S/P index of 1.50 ± 0.4 and the highest S/P was 2.36 ± 0.1 from 28 days post inoculation. The IPMA method showed that the antibody titer of the vaccine reached ≥ 1/160 in 100% of pigs from 21 days post inoculation andreached ≥ 1/640 in 100% of pigs from 28 days post inoculation, indicating that the vaccine was effective at protecting 100% of pigs from 28 days post inoculation. The protective effect of the vaccine was evaluated by the virulent challenge from 28 days post inoculation with 1 dose/animal compared with the control group. The results showed that compared with all pigs in the control group with typical clinical manifestations of Blue-ear disease, all inoculated pigs had normal body temperature and weight gain, besides, the S/P index increased from 1.65 ± 0.1 to the highest 2.99 ± 0.2; the average antibody titer was >1/2560, and virus wasnot detected in nasal fluid by real-time RT-PCR from 7 days post challenge. These experimental results confirmed the safety and efficacy of the attenuated PRRS vaccine based on BG895strain.

Determination of Sero-Prevalence of SARS-CoV-2 antibody among immunized individuals with Covid-19 vaccine in a tertiary center, Nepal

Background: Coronavirus Disease 2019 (covid-19) is a highly contagious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). People who are infected with SARS-CoV-2 or are vaccinated with covid-19 vaccines are supposed to develop immunoglobulins and these immune responses in human body will determine the efficacy of the vaccines as well as help to discover new therapeutic options. Methods: A cross-sectional study conducted between April to June, 2021, assessing serum antibody titer from participants who had taken the first dose of covishieldTM vaccine (naïve as well as prior covid-19 infected individuals). Antibody testing was carried out with Roche Elecsys Anti-SARS-CoV-2 S electrochemiluminescence immunoassay on Roche Cobas e 601 module. Twenty-eight of these participants had follow up repeat antibody test after second dose of vaccine. Results: A total of 122 participants with the first dose of CovishieldTM vaccine were all tested seropositive, antibody titer ranging from minimum of 2.95 U/mL to maximum 2500 U/mL. Average antibody titer was 308.9 U/mL for naive cohort and 1604 U/mL for prior covid-19 infection. In twenty-eight participants who had antibody titer measured after 1 month of second dose, average titer was 1459.7 U/mL for naïve cohort and 1803.4 U/mL for prior covid-19 infected individuals, which was statistically significant compared to antibody response after the first dose. Conclusions: Antibody responses against SARS-CoV-2 following immunization was 100%, with significant development after second dose in naïve population while robust immune response was present after first dose in prior SARS-CoV-2 infected individuals.

A Lower Level of Post-Vaccinal Antibody Titer against Influenza Virus A H1N1 May Protect Patients with Autoimmune Rheumatic Diseases from Respiratory Viral Infections

Background and Objectives: The concentration of antibodies against virus influenza A H1N1 in the titer (≥1:32) positively correlates with resistance to flu in healthy persons. In elderly and immune-compromised patients, an influenza vaccine may be less immunogenic. Hypothesis: A lower post-vaccinal antibody titer (≥1:16) may be sero-protective against respiratory viral infections in patients with autoimmune rheumatic diseases. Materials and Methods: Fifty patients with autoimmune rheumatic diseases (Systemic Lupus Erythematosus—24; Rheumatoid Arthritis—15; and Sjögren’s Syndrome—11), who were at least 65 years old or whose relative disease duration (disease duration/age) was greater than 1/8, were examined. Thirty-four of them were vaccinated with a trivalent inactivated non-adjuvant influenza vaccine. The antibody concentration against influenza virus A H1N1 was measured using the standardized hemagglutination inhibition test and patients who got any respiratory viral infection were registered. To test the hypothesis, a correlative analysis was applied, followed by a binary logistic regression that included potential confounding variables, such as age, disease duration and therapy (personal/health-related conditions). Results: Vaccinated patients were significantly less affected by respiratory viral infections (21% vs. 75%). The lower titer considered (≥1:16) was significantly present more often among vaccinated patients (68% vs. 6%). The correlation between its presence/absence and that of respiratory viral infections was –0.34 (p < 0.05). The binary logistic regression evidenced the relevance of this correlation, confirming the hypothesis. Vaccination was associated with the 87.3% reduction in the likelihood of getting respiratory viral infections, whereas the lower antibody titer (≥1:16) was associated with the 77.6% reduction in the likelihood of getting respiratory viral infections. The vaccine was well tolerated by all patients and after vaccination no exacerbation of the underlying disease was observed. Conclusions: A lower antibody titer (≥1:16) against influenza virus A H1N1 could be protective against respiratory viral infections for certain autoimmune rheumatic diseases patients, which confirms the clinical effectiveness of influenza vaccination.

Immunostimulant Activity of Marchantia paleacea Bertol. Herb Liverwort Ethanol Extract in BALB/c Mice

Immunostimulants are compounds that can stimulate an immune response by increasing the activity of non-specific and specific components of the immune system (humoral and cellular) against certain infections and diseases. The liverwort plant species Marchantia paleacea Bertol. has long been used as a source of nutrition and empirical medicine. However, scientifically there is still not much research data on immunomodulators in these plants. This study aims to determine the activity of immunomodulators in the ethanol extract of the herb Marchantia paleacea Bertol. in male mice of BALB/c strain. Bioactive compounds from this plant were extracted by maceration method using 96% ethanol. Extract characterization and phytochemical screening were determined according to WHO guidelines and standard procedures from previous studies. The immunomodulatory activity of the extract was tested by carbon clearance method and lymphoid organ index (non-specific responses), primary and secondary antibody titer tests (humoral specific responses), IL-2 cytokine levels and IFN-ɣ from serum secondary antibodies and delayed-type hypersensitivity reaction/DTH (cellular specific response). The results of qualitative phytochemical screening contained flavonoid compounds, saponins, phenolics, tannins and steroids/triterpenoids. The results of the non-specific immune response immunomodulator test showed that the dose of 52 mg/kg bw had the largest phagocytic index of 1.52 which included strong immunostimulation (K > 1.5) and the organ spleen index of 0.55 ± 0.11 which increased significantly compared to the control (p<0.05). The data on the acquisition of specific immune responses in the primary and secondary antibody titer test in the three test extracts resulted in increased titer levels compared to the control and at a dose of 52 mg/kg bw could significantly increase the levels of IL-2 cytokines in the control group (p<0,05). Meanwhile, in the DTH test, doses of 13 and 26 mg/kg bw could significantly increase the thickness of the soles of mice compared to controls (p<0.05).

Seven-Month Analysis of Five SARS-CoV-2 Antibody Assay Results after ChAdOx1 nCoV-19 Vaccination: Significant Decrease in SARS-CoV-2 Antibody Titer

We investigated the longevity rates of antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) after a complete ChAdOx1 nCoV-19 vaccination, which are rare and important to estimate their efficacy and establish a vaccination strategy. We assessed the positivity rates and changes of titers before (T0) and at one month (T1), four months (T2), and seven months (T3) after a ChAdOx1 nCoV-19 vaccination using five SARS-CoV-2 antibody assays. A total of 874 serum samples were obtained from 228 (T0 and T1), 218 (T2), and 200 (T3) healthcare workers. The positive rates for all five assays were 0.0–0.9% at T0, 66.2–92.5% at T1, 98.2–100.0% at T2, and 66.0–100.0% at T3. The positive rates at T3 were decreased compared to those at T2. The median antibody titers of all the assays at T3 were significantly decreased compared to those at T2 (860.5 to 232.0 U/mL for Roche total, 1041.5 to 325.5 AU/mL for Abbott IgG, 10.9 to 2.3 index for Siemens IgG, 99.5% to 94.7% for SD Biosensor V1, and 88.5% to 38.2% for GenScript). A third-dose scheme can be considered based on our data generated from five representative assays. Our findings contribute insights into SARS-CoV-2 antibody assays and appropriate vaccination strategies.

Humoral Response among Patients with Interstitial Lung Disease Vaccinated with the BNT162b2 SARS-Cov-2 vaccine - A Prospective Cohort Study

Background: Patients with interstitial lung disease (ILD) are at high risk of severe COVID-19 infection. Additionally, their anti-inflammatory and antifibrotic treatment may cause immunosuppression. Nevertheless, their ability to mount an adequate immune response to messenger RNA SARS-CoV-2 vaccines was not evaluated. We aimed to evaluate the humoral response after the BNT162b2 vaccine among idiopathic pulmonary fibrosis (IPF) patients treated with antifibrotic therapy and among non-IPF ILD patients treated with anti-inflammatory therapy.Methods: We conducted an observational prospective cohort study to evaluate the rate of anti-spike (S-IgG) antibodies after two doses of the BNT162b2 vaccine in patients with ILD. The cohort included 40 patients with idiopathic pulmonary fibrosis (IPF) treated with anti-fibrotic therapy and 29 patients with non-IPF ILD treated with anti-inflammatory therapy. For S-IgG titer measurement one serology test was drawn from all patients 4-6 months after the second vaccine dose. Two age and sex matched control groups were created from a healthy control cohort of 107 patients. The study was conducted in Rabin Medical Center (Israel) between June to August 2021.Results: All patients in the anti-fibrotic arm were seropositive (40/40), corresponding to the matched control group (P=1.0). The antifibrotic arm had a significantly lower median antibody titer in comparison to the matched control group (361.10 [ IQR, 207-811] AU/ml vs 820.75 [IQR, 459-1313] AU/ml; P<0.001). Only 48.3% (14/29) of patients in the anti-inflammatory arm were seropositive in comparison to 100% (29/29) in the healthy control group (P<0.001). The anti-inflammatory arm had a significantly lower median antibody titer in comparison to the healthy control group (39.6 [ IQR, 4.25-165] AU/ml vs 970.1 [IQR, 505-1926] AU/ml; P<0.001). Conclusion: IPF patients treated with antifibrotic therapy mount an adequate immune response after 2 doses of the BNT162b2 vaccine, maintain a 100% seropositivity rate, 4-6 months after vaccination. However, their antibody titer was reduced in comparison to a healthy control group. Among patients with non-IPF ILD, treated with anti-inflammatory therapy, 48% were seronegative 4-6 months after the second vaccine dose, moreover treatment with rituximab caused significant immunosuppression, even in comparison to other anti-inflammatory treatments.

Prolonged COVID-19 infection in a child with lymphoblastic non-Hodgkin lymphoma: which is the best management?

During the coronavirus disease 2019 (COVID-19) pandemic, oncologists have managed patients at higher risk of having a severe course of this infection. This raises new questions about their correct management, as well as the difficulty of distinguishing tumor/treatments complications from those related to COVID-19. We report a case of an 11-year-old boy undergoing treatment for T-cell lymphoblastic lymphoma who experienced a prolonged COVID-19 course. Oncologic therapy was continued without significant changes compared to the initially planned treatment. No relevant complications occurred. COVID-19 convalescent plasma was administered, resulting in a positive antibody titer after 24 days.

Diversity in antibody titer at an average of 87 days after the second dose of BNT162b2 mRNA coronavirus disease 2019 vaccine: data from a predominantly elderly population in a practice in Tokyo

It is very important for the elderly, who tend to have serious COVID-19 infection and high mortality rates, to maintain sufficient immunity. We reviewed the medical charts of predominantly elderly population to obtain the data on serum anti-SARS-CoV-2S antibody titer after complete vaccination with the BNT162b2 mRNA vaccine (two doses) and evaluated the background factors associated with the titer. We enrolled 230 participants (101 men and 129 women). Their average age was 71.9 (SD 12.5) years, and median was 72 years. The anti-SARS-CoV-2S antibody titer varied from 0.55 U/mL to 4920 U/mL. We found that the value of the titer varied widely. The value of the titer was negatively associated with age, alcohol consumption, time elapsed from second vaccine dose, and use of immunosuppressive medication. The result that the titer was negatively associated with aging suggests that the timing of additional shot should be carefully determined especially among elderly population.