A195 DURABILITY OF SEROLOGICAL RESPONSES AFTER SECOND, THIRD AND FOURTH DOSE OF SARS-COV-2 VACCINATION IN INFLAMMATORY BOWEL DISEASE: A PROSPECTIVE COHORT STUDY

Background

Adequate serological responses following two-dose regimens and additional doses of SARS-CoV-2 vaccination have been demonstrated for the vast majority of those with IBD. However, antibody levels following 2^nd, 3^rd, and 4^th dose SARS-CoV-2 vaccination may decrease over time in the IBD population.

Purpose

We assessed the durability of serological responses to 2^nd, 3^rd, and 4^th dose SARS-CoV-2 vaccination over time in a cohort of IBD patients.

Method

Adults with IBD who received at least one dose of a SARS-CoV-2 vaccine (n=559) were evaluated for serological response to the spike protein of SARS-CoV-2 using the Abbott IgG II Quant assay with a seroconversion threshold of ≥ 50 AU/mL. The geometric mean titer (GMT) with 95% confidence intervals (CI) were calculated and stratified by weeks (1–8, 8–16, 16–24, 24+ weeks) after each vaccine dose. We compared stratified GMTs with Mann–Whitney U tests using a significance level of 0.05.

Result(s)

Our cohort (n=559) comprised the following patient characteristics: 82.8% were 18–65 years-old (n = 463), 53.1% were female (n =297), and 71.6% had Crohn’s disease (n =400). IBD medications were classified in the following mutually exclusive groups: No immunosuppressives 10.5% (n = 59), anti-TNF monotherapy 35.8% (n = 200), immunomodulatory monotherapy 2.1% (n =12 ), vedolizumab 11.8% (n =66 ), ustekinumab 20.4% (n =114 ), tofacitinib 1.2% (n =7 ), combination therapy 15.9% (n = 89), and prednisone 2.1% (n =12). For vaccine type, 85.6% and 82.3% had Pfizer for 3^rd and 4^th dose, respectively, while the remainder had Moderna. Seroconversion rates 1–8 weeks after 3^rd and 4^th dose were both 99.9%.

Figure 1 compares GMTs with 95% CI by weeks after each vaccine dose. GMTs are highest 1–8 weeks after 2^nd dose (4053 AU/mL; 95% CI: 3468, 4737 AU/mL; n=337), 3^rd dose (12116 AU/mL; 10413, 14098 AU/mL; n=256), and 4^th dose (14337 AU/mL; 10429, 19710 AU/mL; n=67). Subsequently, antibody levels decay from 1–8 weeks to 8–16 weeks (p<0.001) for 2^nd dose (mean difference: –2224 AU/mL), 3^rd dose (mean difference: –7526 AU/mL), and 4^th dose (mean difference: –9715 AU/mL). Compared to 16–24 weeks after 2^nd dose, antibody levels 24+ weeks after were similar (GMTs: 795 AU/mL vs. 1043 AU/mL, p=0.52). For third dose, antibody levels 8–16 weeks and 16–24 weeks after vaccination were similar (4590 AU/mL vs. 4073 AU/mL, p=0.73) along with 16–24 weeks compared to 24+ weeks after vaccination (4073 AU/mL vs. 5876 AU/mL, p=0.18).

Image

Conclusion(s)

Within 1–8 weeks after each dose of vaccine, serological responses spikes with each subsequent dose yielding a higher GMT. While antibody levels decay 8–16 weeks after each dose, similar GMT levels beyond 16 weeks may indicate durability of antibody levels over a longer duration of time.

Disclosure of Interest

None Declared

A246 THE GLOBAL INCIDENCE OF ACUTE PANCREATITIS IS INCREASING OVER TIME: A SYSTEMATIC REVIEW AND META-ANALYSIS

Background

Acute pancreatitis is a common disease with significant associated morbidity and mortality. Historically, acute pancreatitis has been considered a disease with multiple etiologies and risk factors but is driven by alcohol and biliary disease. Multiple studies have shown that the incidence of acute pancreatitis is increasing globally among both adults and children.

Aims

The purpose of this study was to assess temporal trends in incidence of acute pancreatitis globally.

Methods

We performed a systematic literature search to identify population-based studies reporting the annual incidence of acute pancreatitis. Abstracts were independently assessed in duplicate to identify applicable papers for full-text review and data extraction. Joinpoint temporal trend analyses were performed to calculate the average annual percent change (AAPC) with 95% confidence intervals (CI). The AAPCs were pooled in a meta-analysis to capture the overall and regional trends in acute pancreatitis incidence over time. Temporal data were summarized in a static map and an interactive, web-based map to illustrate global differences.

Results

Forty-five studies reported the temporal incidence of acute pancreatitis (static map provided, online interactive map: https://kaplan-acute-pancreatitis-ucalgary.hub.arcgis.com/). The incidence of acute pancreatitis has increased from 1961 to 2016 (AAPC = 2.89%; 95% CI: 2.26, 3.52; n=41). Increasing incidence was observed in North America (AAPC = 2.71%; 95% CI: 1.93, 3.50; n=10) and Europe (AAPC = 2.79%; 95% CI: 1.95, 3.63; n=24). The incidence of acute pancreatitis was stable in Asia (AAPC = −0.28%; 95% CI: −5.03, 4.47; n=2).

Conclusions

This meta-analysis provides a comprehensive overview of the global incidence of acute pancreatitis over the last five decades and demonstrates a steadily rising incidence over time in most countries of the Western world. More studies are needed to better define the changing incidence of acute pancreatitis in Asia, Africa and Latin America.

Funding Agencies

None

A28 RELATIVE RATES OF ULCERATIVE COLITIS TO CROHN’S DISEASE: PARALLEL EPIDEMIOLOGIES IN NEWLY VS. HIGHLY INDUSTRIALIZED COUNTRIES

Background

Inflammatory bowel disease (IBD) first presents in a population as cases of ulcerative colitis (UC) followed by cases of Crohn’s disease (CD). Newly industrialized countries (NIC) show a prallel epidemiology of IBD to highly industrialized countries (HIC) in the previous century; one marker of this is the relative incidence/prevalence rates of UC to CD, which approximates 1 over time.

Aims

Provide evidence for the UC:CD ratio as a proxy for disease penatrance in a population.

Methods

Systematic review of MedLine and Embase for studies reporting incidence or prevalence of UC and CD. Log-linear regression (by region and NIC/HIC [2019 United Nations definitions]) was used to calculate average annual percent change (AAPC) and associated 95% confidence intervals (CI). Data were plotted on an online, interactive map to show trends (link provided).

Results

We extracted data from 218 studies compising population-level data from 69 countries. We found negative AAPCs as the prevalence ratio of UC:CD significantly decreased over time in East Asia, West Asia, North Europe, and South Europe; 6/12 global regions displayed significantly decreasing incidence ratios. No AAPC was found to be significantly increasing (Table 1). When examing HIC/NIC, we found a significant effect of NIC on the UC:CD prevalence ratio after 2000 (AAPC:−3.83;95%CI:−6.28,−1.31) while HIC regions remained stable (AAPC:2.14;95%CI:−1.40,5.82). Looking at all available data, both HICs and NICs show significantly decreasing UC:CD prevalence ratios (HIC:AAPC:−3.72;95% CI:−4.46,−2.97; NIC:AAPC:−2.62;95%CI:−4.13,−1.08).

Conclusions

In some HICs (eg. Canada), the UC:CD incidence ratio was &lt;1 in the earliest available data (1966), explaining the stable AAPC in North America (AAPC:−0.24;95%CI:−1.12,0.65). However, in NICs (eg. Southern Asia), the AAPC is rapidly decreasing (AAPC:−24.68;95%CI:−37.85,−8.71) as areas like Sri Lanka rapidly fall from an incidence ratio of 7.5 (2007) to 2.8 (2012), mimicking trends in IBD epidimeology of HICs in the previous century.

Funding Agencies

None

Dilemma of rural obstetrics. One community's solution

PROBLEM BEING ADDRESSED

Increasing workload and concerns about physician exhaustion necessitated reorganizing the delivery of obstetric services on Manitoulin Island in Ontario.

OBJECTIVE OF PROGRAM

To organize obstetrics in a remote rural community to provide safe, accessible care, improve working conditions for local physicians, and involve the local hospital and health care workers in the solution.

MAIN COMPONENTS OF PROGRAM

A prenatal clinic for all obstetric care on the island was established. It was based at the local hospital and organized by a nurse-midwife. Local physicians rotated through the clinic and provided obstetric coverage on their on-call days.

CONCLUSIONS

The clinic has helped improve working conditions for local physicians and maintain high-quality obstetric care in this remote area. Local women's initial resistance to the clinic seems to be disappearing with time. Ongoing chart audits reveal intervention rates similar to those found in other Canadian studies of rural obstetric care.