Imprecision in adverse event reports following immunization against HPV in Japan and COVID-19 in the USA, UK, and Japan-and the effects of vaccine hesitancy and government policy.

INTRODUCTION: Erroneous reports of adverse events following immunization (AEFIs) likely exacerbated the 2013 collapse of Japan's HPV immunization program. A similar phenomenon characterized the first months of COVID-19 immunization programs in the USA, UK, and Japan with high rates of reported anaphylaxis. These reports illustrate the susceptibility of supposedly objective medical judgments to public anxiety. PURPOSE AND METHODS: This study documents inaccuracies in reported AEFIs using three quantitative methods. RESULTS: One of these quantitative methods revealed that false-positive rates for anaphylaxis reports following HPV and later COVID-19 vaccination ranged from 74 to 91 percent. However, unlike HPV vaccinations in Japan, anaphylaxis reports following COVID-19 vaccines fell in Japan, the USA and the UK in the latter months of 2021. Nevertheless, false-positive rates for anaphylaxis reports remained high, suggesting a high degree of imprecision in serious AEFI reports from many countries for many vaccines. Japan's HPV immunization program indicates that media reports, patient hesitancy, healthcare providers' perspectives on vaccine safety, and consistency of government messaging, all influence report number and accuracy. A parallel publication analyzes in depth how such factors affect AEFI reports. CONCLUSION: Confidence in the safety of the COVID-19 vaccines may have been bolstered trough rapid monitoring of AEFI reports and communication of these findings. This may partly explain the different trajectories of serious AEFI following HPV immunizations in Japan and COVID-19 immunizations in the USA, UK, and Japan.

Surveillance on Adverse Events Following COVISHIELD (ChAdOx1 nCoV-19) vaccination in Goa, India: An observational study.

BACKGROUND: COVISHIELD, ChAdOx1 nCoV- 19 Corona Virus Vaccine was granted emergency use authorization (EUA) as the first vaccine in India in January 2021. Knowing what to anticipate after vaccination will reduce vaccine hesitancy in the public. This study aimed to identify and measure the adverse events following COVID-19 vaccination. MATERIALS AND METHODS: A cross-sectional observational study was conducted at Goa Medical College, starting on February 21 till May 23, 2021. A total of 418 people were enrolled. We collected the data using the Microsoft Form and analyzed using Microsoft Excel and R-program. RESULTS: Of the 418 vaccine recipients, the incidence rate of AEFI (Adverse Events Following Immunization) was 54.31%. Fever, fatigue, and headache were the most commonly reported systemic AEFIs. Among these, 54.7% of AEFI were mild, 42.38% were of the moderate category, and only 2.96% were of grade 3 severity. None of the AEFIs were severe enough for hospitalization. Most of them developed symptoms within 24 hours of the first dose. Complete recovery from AEFIs took a median time of 24 hours. CONCLUSION: Most of our study findings were consistent with the phase 1, 2/3 trials findings of Oxford-AstraZeneca's ChAdOx1 vaccine. The AEFI symptoms were considered immune reactions to the vaccine. The AEFIs were more common among younger individuals and females. The chance of missing a serious adverse event like a thromboembolic phenomenon cannot be ruled out. We observed low AEFI rates with COVISHIELD in the Indian population compared to Oxford-AstraZeneca's ChAdOx1 vaccine in the UK-based population, which can be explained by pre-existing immunity against adenovirus in the Indian population. However, based on the study findings, we may interpret that the COVISHIELD, Serum Institute of India, carries a good safety profile overall.

Risk Factors and Incidence Rates of Self-Reported Short-Term Adverse Events of COVID-19 Vaccine Booster Dose.

With the spread of the new SARS-CoV-2 variants, many countries have begun COVID-19 vaccine booster programs with the mix-and-match strategy. However, research on the adverse events (AE) of booster doses is still scarce. The aim of our study was to analyze the reported incidence rate (IR), and factors associated with AE, including short-term serious adverse events (SAE) and short-term non-serious adverse events (NSAE), among different vaccine products through the hospital-based Vaccine Adverse Event Reporting System (VAERS). A total of 7432 records were collected during the three-month study period. While more than half of the responses (52.2%) reported the presence of AE after receiving a booster dose, only a few AE were considered SAE (2.4%). AE were significantly higher among women and people of younger age, and the brand of vaccines is the strongest factor associated with post-booster dose AE. The incidence of AE in mRNA1273 is higher than in BNT162b2 and MVC-COV1901 (IRR mRNA1273 vs. BNT162b2: 1.22, 95% CI: 1.11-1.34; BNT162b2 vs. MVC-COV1901: 2.77, 95% CI: 2.27-3.39). The IR of different groups were calculated to support the decision making of the booster vaccine. Although AE were not uncommon for booster vaccines, almost all AE were not serious and predictable using estimated IR. This result can be used to optimize booster vaccine decision making.

Sick leave request following anti-COVID-19 vaccine administration is low among healthcare workers: results from a retrospective cross-sectional monocentric study

OBJECTIVE: Anti-COVID-19 vaccines were mainly associated with non-serious adverse events (AEs), whose prevalence was reported to be up to 70% in healthcare workers (HCWs). This may lead to sick leave requests, but this impact has never been quantified. This study aimed to investigate the absence from work among HCWs following anti-COVID-19 vaccination. Its association with age and previous COVID-19 infection was also assessed. PATIENTS AND METHODS: This is a retrospective observational cross-sectional study on administrative data about sick leave requests after anti-COVID-19 vaccination. All the HCWs employed at the Niguarda Hospital (Milan, Italy) who received the vaccine from December 27, 2020 to February 28, 2021 were included. RESULTS: In total, 4,088 HCWs received the first dose of the vaccine and 4,043 completed the vaccination cycle. After the first injection, 1.6% of HCWs requested sick leave, while after the second injection, the number of requests significantly increased (+6.1%, p<0.001). A significant increase in sick leave was detected for those who have had SARS-CoV-2 infection after the first injection (+2.3%, p<0.001). After the second dose, a significant increase in sick leave was observed in the 20-30-year-old group compared to >30 years (+3.6%, p=0.017), if HCWs without a history of SARS-CoV-2 infection were considered. CONCLUSIONS: The requests for sick leave among HCWs following the anti-COVID-19 vaccine were limited and higher after the second injection. This may help the management of the human resources when the large-scale administration of the anti-COVID-19 vaccines will involve other categories of workers.

Adverse events following ChAdOx1 nCoV-19 Vaccine (COVISHIELD) amongst health care workers: A prospective observational study.

BACKGROUND: During ongoing COVID-19 pandemic, researchers worked enormously to develop effective vaccines against COVID-19 infection. Two Indian-made vaccines [Covishield (ChAdOx1 nCoV-19) and Covaxin] were granted Emergency Use Authorization. India launched its COVID-19 vaccination drive starting with healthcare workers (HCW). Aim of the study was to evaluate adverse events following immunization (AEFI) amongst the HCW with two doses of Covishield vaccine. We also evaluated association of AEFI according to sex, profession and age groups. METHODS: A prospective observational study was conducted in a tertiary care COVID dedicated hospital of Southern India from 16 Jan - 15 Apr 2021. Nine hundred and eighty one HCW who received 2 doses (4 weeks apart) were enrolled. Active and passive surveillance was conducted after 48 hours, and at days 8,15, 22 and 28 for both doses. The rate of AEFI for each dose was determined. Incidence and association of AEFI with various demographic variables was determined. RESULTS: 1020 non-serious and two serious AEFI (altered sensorium) were reported within 48 hours of first dose. Two hundred and twenty non-serious AEFI were reported within 48 hours of second dose. No AEFI was reported after 15 days for both the doses. We found no association of AEFI with sex and profession ( p >0.5). Significant association of AEFI was found with age ( p <0.01). CONCLUSION: Short-term AEFI were predominantly observed in first 48 hours. Incidence decreased in subsequent weeks with no occurrence after 15 days in both doses. Symptoms were mild in severity and short-lived. No serious AEFI attributable to vaccines were reported.