Immunogenicity of SARS-CoV-2 vaccines BBV152 (COVAXIN®) and ChAdOx1 nCoV-19 (COVISHIELD™) in seronegative and seropositive individuals in India: a multicentre, nonrandomised observational study.

Background: There are limited global data on head-to-head comparisons of vaccine platforms assessing both humoral and cellular immune responses, stratified by pre-vaccination serostatus. The COVID-19 vaccination drive for the Indian population in the age group 18-45 years began in April 2021 when seropositivity rates in the general population were rising due to the delta wave of COVID-19 pandemic during April-May 2021. Methods: Between June 30, 2021, and Jan 28, 2022, we enrolled 691 participants in the age group 18-45 years across four clinical sites in India. In this non-randomised and laboratory blinded study, participants received either two doses of Covaxin® (4 weeks apart) or two doses of Covishield™ (12 weeks apart) as per the national vaccination policy. The primary outcome was the seroconversion rate and the geometric mean titre (GMT) of antibodies against the SARS-CoV-2 spike and nucleocapsid proteins post two doses. The secondary outcome was the frequency of cellular immune responses pre- and post-vaccination. Findings: When compared to pre-vaccination baseline, both vaccines elicited statistically significant seroconversion and binding antibody levels in both seronegative and seropositive individuals. In the per-protocol cohort, Covishield™ elicited higher antibody responses than Covaxin® as measured by seroconversion rate (98.3% vs 74.4%, p < 0.0001 in seronegative individuals; 91.7% vs 66.9%, p < 0.0001 in seropositive individuals) as well as by anti-spike antibody levels against the ancestral strain (GMT 1272.1 vs 75.4 binding antibody units/ml [BAU/ml], p < 0.0001 in seronegative individuals; 2089.07 vs 585.7 BAU/ml, p < 0.0001 in seropositive individuals). As participants at all clinical sites were not recruited at the same time, site-specific immunogenicity was impacted by the timing of vaccination relative to the delta and omicron waves. Surrogate neutralising antibody responses against variants-of-concern including delta and omicron was higher in Covishield™ recipients than in Covaxin® recipients; and in seropositive than in seronegative individuals after both vaccination and asymptomatic infection (omicron variant). T cell responses are reported from only one of the four site cohorts where the vaccination schedule preceded the omicron wave. In seronegative individuals, Covishield™ elicited both CD4+ and CD8+ spike-specific cytokine-producing T cells whereas Covaxin® elicited mainly CD4+ spike-specific T cells. Neither vaccine showed significant post-vaccination expansion of spike-specific T cells in seropositive individuals. Interpretation: Covishield™ elicited immune responses of higher magnitude and breadth than Covaxin® in both seronegative individuals and seropositive individuals, across cohorts representing the pre-vaccination immune history of most of the vaccinated Indian population. Funding: Corporate social responsibility (CSR) funding from Hindustan Unilever Limited (HUL) and Unilever India Pvt. Ltd. (UIPL).

Feasibility and acceptability of the paediatric pulse oximeter in integrated management of neonatal and childhood illnesses (IMNCI) services by public health facilities: A qualitative study in rural Western India.

Background: Pneumonia contributes to about 15% of child deaths globally, with 20% of the overall deaths occurring in India. Although WHO recommends the use of pulse oximeters (PO) in first-level facilities for early detection of child pneumonia in low- and middle-income countries (LMICs), this has not yet been implemented in India. We aimed to assess the feasibility and acceptability of introducing PO in integrated management of neonatal and childhood illnesses (IMNCI) services at primary health centres (PHC) in the rural Pune district. Methods: We identified medical officers (MO) and auxiliary nurse midwives (ANM) from six PHCs as study participants due to their involvement in the treatment of children. We developed in-depth interview (IDI) guides for both groups to explore their IMNCI knowledge and attitude towards the program through a qualitative study. We conducted interviews with MOs (n = 6) and ANMs (n = 6) from each PHC. The PO module was added to explore perceptions about its usefulness in diagnosing pneumonia. After baseline assessment, we conducted training sessions on adapted IMNCI services (including PO use) for MOs and ANMs. PO devices were provided at the study PHCs. Results: At baseline, no PO devices were being used at study PHCs; PHC staff demonstrated satisfactory knowledge about paediatric pneumonia management and demanded refresher IMNCI training. They also felt the need to reiterate the PO use for early diagnosis of pneumonia in children and highlighted the challenges encountered in managing pneumonia at PHCs, such as health system-related challenges and parents' attitudes towards care seeking. There was positive acceptance of training and PO started to be used immediately in PHCs. There was increased confidence in using PO at endline. PO use in examining symptomatic children increased from 26 to 85%. Conclusions: Paediatric PO implementation could be integrated successfully at PHC levels; we found pre-implementation training and provision of PO to PHCs to be helpful in achieving this goal. This intervention demonstrated that an algorithm to diagnose pneumonia in children that included PO could improve case management.

Effect of reduced two-dose (1+1) schedule of 10 and 13-valent pneumococcal conjugate vaccines (SynflorixTM and Prevenar13TM)) on nasopharyngeal carriage and serotype-specific immune response in the first two years of life: Results from an open-labelled randomized controlled trial in Indian children.

INTRODUCTION: This study aimed to assess the effect of a reduced dose regime (1 + 1) of PCV10 and PCV13 along with 3-dose regimes on pneumococcal vaccine-type (VT) carriage and immunogenicity in the first two years of life in PCV-naïve Indian children. METHODS: A total of 805 healthy infants aged 6-8 weeks were randomised to 7 groups (n = 115). Six groups received SynflorixTM(PCV10) or Prevenar13TM(PCV13) in the following schedules: 3 + 0 (three primary at 6, 10, and 14 weeks); 2 + 1 (two primary 6 and 14 weeks with booster at 9 months; 1 + 1 (one primary at 14 weeks with booster at 9 months). The 7th group was a PCV-naïve control group. Nasopharyngeal swabs were collected at 6, 18 weeks, 9, 10, 15, and 18 months of age. Venous blood samples were collected at 18 weeks, 9, 10, and 18 months of age for assessment of sero-specific IgG antibodies. Additionally, functional activity using a serotype specific opsonophagocytic assay (OPA) was assessed at 10 and 18 months of age in a subset (20%) of participants. RESULTS: All schedules of PCV13 showed significant 13VT carriage reduction in the second year of life as compared to control. At 15 months of age, PCV13 (1 + 1) showed 45 % reduction in 13VT-carriage compared to the control [OR = 0.55 (95% CI; 0.31-0.97), p= 0.038]. None of the PCV10 schedules showed significant reduction in 10VT carriage in the second year. Although not powered for these outcomes, at 18 months of age, 1 + 1 and 2 + 1 schedules of both vaccines demonstrated higher sero-responders for all serotypes, higher geometric mean concentrations (GMC) for all serotypes except 23F [with both vaccines], higher percent OPA responders and OPA geometric mean titres (GMT) compared to the 3 + 0 schedules for all serotypes. CONCLUSION: The reduced dose schedule (1 + 1) of PCV13 results in significant VT-carriage reduction in the second year of life. Immune protection provided by 1 + 1 schedules of PCV10 and PCV13 in the second year of life is comparable to WHO-recommended 3-dose schedules.

Seroprevalence of SARS-CoV-2 specific Immunoglobin G antibodies in rural population of Western Maharashtra, India.

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, responsible for the coronavirus disease 2019 (COVID-19) pandemic, has been a major public health concern requiring continuous efforts for understanding its epidemiology. Patients infected with SARS-CoV-2 have a wide range of clinical features ranging from asymptomatic infection to mild or severe illness with fatal outcomes or recovery. Population-based seroepidemiological studies are an effective method for measuring the rapid spread of SARS-CoV-2 and monitoring the pandemic's progress. Methods: We conducted repeated cross-sectional community-based sentinel surveillance between January and June 2021 in the rural parts of the Pune district of Maharashtra, India to assess the seroprevalence against SARS-CoV-2 in three age categories. We selected 30 clusters for each round using a proportional population sampling method and 30 individuals in each of the three age groups (1-17 years, 18-49 years, and ≥50 years). We took blood samples from consenting study participants to check for the presence of Immunoglobulin G (IgG) antibodies against SARS-CoV-2 in all five rounds. Results: We included 14 274 individuals across five rounds; 29% were from the 1-17, 39% from the 18-49, and 32% from the ≥50-year-old group. Overall seroprevalence combining all rounds was 45%. There was an increase in seropositivity in rounds four (51.15%) and five (58.32%) contributed mostly by adults. We found that about 72% of elderly individuals ≥50 years in round five were seropositive. The factors strongly associated with the seropositivity were being in contact with suspected or confirmed cases of COVID-19 (odds ratio (OR) = 7.15; 95% confidence interval (CI) = 4.2-12.14), receiving at least one dose of COVID-19 vaccine (OR = 3.13 (95% CI = 0.70-14.07), being aged ≥50 years (OR = 1.97; 95% CI = 1.81-2.15), and being in an occupation belonging to a high-risk category (OR = 1.92; 95% CI = 1.65-2.26). Among 135 hospitalizations reported due to COVID-19-like illness, 91 (67%) were in the elderly age group of ≥50 and 33 (24%) were in the 18-49-year-old age group. Conclusions: Seroprevalence of SARS-CoV-2 was high in the last two rounds (April to June 2021) which coincide with the second wave of the pandemic (Delta variant B.1.617.2) in India. Overall, one in three children and one in two adults had antibodies for SARS-CoV-2. The suspected or confirmed case of COVID-19 emerged as the significant factor strongly associated with the seropositivity followed by COVID-19 vaccination.

Determinants of maternal influenza vaccination in the context of low- and middle-income countries: A systematic review.

BACKGROUND: Pregnancy and early infancy are considered to be the vulnerable phases for severe influenza infection causing morbidity and mortality. Despite WHO recommendations, influenza is not included in the immunization programs of many low- and middle-income countries. This systematic review is aimed at identifying barriers and facilitators for maternal influenza vaccination amongst the perinatal women and their health care providers in low- and middle-income countries. METHODS: We selected 11 studies from the 1669 records identified from PubMed, CABI, EMBASE and Global Health databases. Studies related to both pandemic and routine influenza vaccination and studies conducted amongst women in the antenatal as well as postnatal period were included. Both qualitative, quantitative, cross-sectional and interventional studies were included. RESULTS: Knowledge about influenza disease, perception of the disease severity during pregnancy and risk to the foetus/newborn and perceived benefits of influenza vaccination during pregnancy were associated with increased uptake of influenza vaccination during pregnancy. Recommendation by health care provider, vaccination in previous pregnancy and availability of vaccine in public health system facilitated vaccine uptake. High parity, higher education, vaccination in the later months of pregnancy, less than 4 antenatal visits, concerns about vaccine safety and negative publicity in media were identified as barriers for influenza vaccination. Lack of government recommendation, concerns about safety and effectiveness and distrust in manufacturer were the barriers for the healthcare providers to recommend vaccination. CONCLUSION: While availability of influenza vaccine in public health system can be a key to the success of vaccine implementation program, increasing the awareness about need and benefits of maternal influenza vaccination amongst pregnant women as well as their health care providers is crucial to improve the acceptance of maternal influenza vaccination in low and middle-income countries.

Nasopharyngeal pneumococcal carriage in South Asian infants: Results of observational cohort studies in vaccinated and unvaccinated populations.

BACKGROUND: Nasopharyngeal pneumococcal carriage (NPC) is a prerequisite for invasive pneumococcal disease and reduced carriage of vaccine serotypes is a marker for the protection offered by the pneumococcal conjugate vaccine (PCV). The present study reports NPC during the first year of life in a vaccinated (with PCV10) cohort in Bangladesh and an unvaccinated cohort in India. METHODS: A total of 450 and 459 infants were recruited from India and Bangladesh respectively within 0-7 days after birth. Nasopharyngeal swabs were collected at baseline, 18 and 36 weeks after birth. The swabs were processed for pneumococcal culture and identification of serotypes by the Quellung test and polymerase chain reaction (PCR). An identical protocol was applied at both sites. RESULTS: Prevalence of NPC was 48% in the Indian and 54.8% in the Bangladeshi cohort at 18 weeks. It increased to 53% and 64.8% respectively at 36 weeks. The average prevalence of vaccine serotypes was higher in the Indian cohort (17.8% vs 9.8% for PCV-10 and 26.1% vs17.6% for PCV-13) with 6A, 6B, 19F, 23F, and 19A as the common serotypes. On the other hand, the prevalence of non-vaccine serotypes was higher (43.6% vs 27.1% for non-PCV13) in the Bangladeshi cohort with 34, 15B, 17F, and 35B as the common serotypes. Overcrowding was associated with increased risk of pneumococcal carriage. The present PCV-13 vaccine would cover 28%-30% and 47%-48% serotypes in the Bangladeshi and Indian cohorts respectively. CONCLUSIONS: South Asian infants get colonised with pneumococci early in infancy; predominantly vaccine serotypes in PCV naïve population (India) and non-vaccine serotypes in the vaccinated population (Bangladesh). These local findings are important to inform the public health policy and the development of higher valent pneumococcal vaccines.

Conducting community-based pediatric research in rural India: Experience from vadu rural health program.

This paper describes unique challenges faced during conduct of community research studies in rural population of Maharashtra at Vadu Rural Health Program, Pune, India. Some of the ethical issues faced include difficulty in comprehending the informed consent by rural families with low education levels and ensuring adequate compensation for study participation without undue inducement, ensuring large number of recruitments during early infancy, ensuring adherence to intervention by care-providers, retention of participants especially in studies having long follow-ups and regulatory compliance for serious adverse event reports are major operational challenges. The delays faced in approvals from the Health Ministry Screening Committee and lack of specific regulatory guidance on community-based conduct of studies pose challenges in terms of study timelines and operational aspect of these studies. Provision of study-related information during prestudy visits, designing patient information sheets in simple language, involving the decision-making member of the family, adequate time for families for decision-making are certain measures that have been useful for effective informed consent administration. Collaboration with accredited social health activists and auxillary nurse midwives for line-listing of pregnancies and births and regular conduction of prestudy visits or community sensitization meetings have been useful for the recruitment of large number of study participants during infancy. Strategies such as provision of universal immunization, selection of field research assistants from the local population, regular home visits, and provision of medical care has been helpful in retention of the study participants. Networking with local health facilities and local government bodies has helped in the provision of medical care to the study participants and in the management of serious adverse events. Our experience can provide important learnings to other investigators from developing countries working in the domain of child health.

Assessment of perceived distress due to nasopharyngeal swab collection in healthy Indian infants participating in a clinical trial.

Routinely children are exposed to various procedures as a part of clinical care and/or research participation. Public health strategies to contain current COVID-19 pandemic demanded massive nasopharyngeal swab testing but limited data exist to confirm the extent of the pain and distress that result from this procedure. These data could help clinicians to formulate mitigation strategies, influence public health directives, and inform review boards/ethics committees to decide on risk-benefit ratio of the procedure. Hence, an observational study to assess perceived distress was nested in a phase IV alternate and reduced dose schedule trial of the pneumococcal conjugate vaccine (PCV) in which nasopharyngeal swab (NPS) was used to collect nasopharyngeal secretions as part of the study procedure. Out of 805 infant participants enrolled in the main study, a total of 425 infants were enrolled and observed for procedural distress at 18 weeks and 10 months of age using the Face Leg Activity Cry and Consolability (FLACC) Scale. The FLACC score and duration of cry were recorded. The mean FLACC score changed substantially from preprocedural to procedure in both age groups (from 0.08 to 5.8 at 18 weeks and from 0.5 to 7.007 at 10 months. P = <.0001). The proportion of infants experiencing higher FLACC scores (7-10) indicating severe distress increased significantly from 22% (n = 95) at 18 weeks to 61% (n = 248) at 10 months (P < .0001). The mean duration of cry was significantly increased from 23.03 seconds at 18 weeks to 52.6 seconds at 10 months (P = .00). Nasopharyngeal swab collection produced substantial distress which increased with age. Adequate training of sample collectors and supporting parent engagement during procedure could help in reducing the distress.

Immunogenicity and lot-to-lot consistency of a ready to use liquid bovine-human reassortant pentavalent rotavirus vaccine (ROTASIIL - Liquid) in Indian infants.

BACKGROUND: A lyophilized bovine-human rotavirus reassortant pentavalent vaccine (BRV-PV, Rotasiil®) was licensed in 2016. A liquid formulation of this vaccine (LBRV-PV, Rotasiil - Liquid) was subsequently developed and was tested for non-inferiority to Rotasiil® and for lot-to-lot consistency. METHODS: This Phase II/III, open label, randomized study was conducted at seven sites across India from November 2017 to June 2018. Participants were randomized into four arms; Lots A, B, and C of LBRV-PV and Rotasiil® in 1:1:1:1 ratio. Three doses of study vaccines were given at 6, 10, and 14 weeks of age. Blood samples were collected four weeks after the third dose to assess rotavirus IgA antibody levels. Non-inferiority of LBRV-PV to Rotasiil was proven if the lower limit two-sided 95% confidence interval (CI) of geometric mean concentration (GMC) ratio was at least 0.5. Lot-to-lot consistency was proven if 95% CI of the GMC ratios of three lots were between 0.5 and 2. Solicited reactions were collected by using diary cards. RESULTS: Of the 1500 randomized infants, 1436 infants completed the study. The IgA GMC ratio of LBRV-PV to Rotasiil® was 1.19 (95% CI 0.96, 1.48). The corresponding IgA seropositivity rates were 60.41% (57.41, 63.35) and 52.75% (47.48, 57.97). The IgA GMC ratios among the three LBRV-PV lots were: Lot A versus Lot B: 1.34 (1.03, 1.75); Lot A versus Lot C: 1.22 (0.93, 1.60); and Lot B versus Lot C: 0.91 (0.69, 1.19). The 95% CIs for the GMC ratios were between 0.69 and 1.75. The incidence of solicited reactions was comparable across the four arms. Only one serious adverse event of gastroenteritis event in the Rotasiil® group was causally related. CONCLUSION: The immunological non-inferiority of LBRV-PV against Rotasiil® as well as lot-to-lot consistency of LBRV-PV was demonstrated. LBRV-PV had safety profile similar to Rotasiil®. TRIAL REGISTRATION NUMBER: Clinical Trials.Gov [NCT03474055] and Clinical Trial Registry of India [CTRI/2017/10/010104].