Timing of HPV vaccination as adjuvant treatment of CIN2+ recurrence in women undergoing surgical excision: a meta-analysis and meta-regression

OBJECTIVE

The main aim was to determine the overall vaccine effectiveness (VE) against recurrent cervical intraepithelial neoplasia grade 2 or worse (CIN2+) including specific VE associated with timing of human papillomavirus (HPV) vaccination using data from published studies.

DESIGN

Meta-analysis and meta-regression.

DATA SOURCES

A computerised literature search was undertaken using the MEDLINE, EMBASE, International Pharmaceutical Abstracts, Derwent Drug File, ProQuest Science and Technology, Cochrane and MedRxiv databases. To be eligible, the studies, with no language restrictions, had to be published between 1 January 2001 and 25 May 2023.

REVIEW METHODS

Included were studies with an unvaccinated reference group that assessed CIN2+ recurrence irrespective of the HPV genotype in women undergoing conisation provided. The present study was carried out in compliance with the Preferred Reporting Items for Systematic Review and Meta-Analyses and Meta-analysis Of Observational Studies in Epidemiology guidelines. The risk of study bias was assessed using the Newcastle-Ottawa Quality Assessment Scale. The Grading of Recommendations Assessment, Development, and Evaluation guidelines were used to assess the strength of evidence for the primary outcome. Data synthesis was conducted using meta-analysis and meta-regression.

RESULTS

Out of a total of 14 322 publications, 20 studies with a total of 21 estimates were included. The overall VE against recurrent CIN2+ irrespective of the HPV genotype achieved 69.5% (95% CI: 54.7% to 79.5%). While the HPV vaccine valency, follow-up duration, type of study including its risk of bias had no effect on VE, the highest VE of 78.1% (95% CI: 68.7% to 84.7%) was reported for women receiving their first dose not earlier than the day of excision. This outcome was supported by additional analyses and a VE prediction interval ranging from 67.1% to 85.4%.

CONCLUSIONS

The outcome of this meta-analysis and meta-regression convincingly showed the beneficial effect of post-excisional HPV vaccination against CIN2+ recurrence. Studies published to date have been unable to determine whether or not vaccination, completed or initiated before conisation, would be associated with more favourable results.

PROSPERO REGISTRATION NUMBER

CRD42022353530.

Risk factors affecting COVID-19 vaccine effectiveness identified from 290 cross-country observational studies until February 2022: a meta-analysis and meta-regression

BACKGROUND

Observational studies made it possible to assess the impact of risk factors on the long-term effectiveness of mRNA and adenoviral vector (AdV) vaccines against COVID-19.

METHODS

A computerized literature search was undertaken using the MEDLINE, EMBASE, and MedRxiv databases to identify eligible studies, with no language restrictions, published up to 28 February 2022. Eligible were observational studies assessing vaccine effectiveness (VE) by disease severity with reference groups of unvaccinated participants or participants immunized with one, two, or three vaccine doses. Our study was carried out in compliance with the PRISMA and MOOSE guidelines. The risk of study bias was identified using the Newcastle-Ottawa Quality Assessment Scale. The GRADE guidelines were applied to assess the strength of evidence for the primary outcome. The synthesis was conducted using a meta-analysis and meta-regression.

RESULTS

Out of a total of 14,155 publications, 290 studies were included. Early VE of full vaccination against COVID-19 of any symptomatology and severity decreased from 96% (95% CI, 95-96%) for mRNA and from 86% (95% CI, 83-89%) for AdV vaccines to 67% for both vaccine types in the last 2 months of 2021. A similar 1-year decline from 98 to 86% was found for severe COVID-19 after full immunization with mRNA, but not with AdV vaccines providing persistent 82-87% effectiveness. Variant-reduced VE was only associated with Omicron regardless of disease severity, vaccine type, or vaccination completeness. The level of protection was reduced in participants aged >65 years, with a comorbidity or those in long-term care or residential homes independently of the number of doses received. The booster effect of the third mRNA dose was unclear because incompletely restored effectiveness, regardless of disease severity, declined within a short-term interval of 4 months.

CONCLUSIONS

Full vaccination provided an early high, yet waning level of protection against COVID-19 of any severity with a strong impact on the high-risk population. Moreover, the potential risk of new antigenically distinct variants should not be underestimated, and any future immunization strategy should include variant-updated vaccines.

The Effectiveness of Post-Vaccination and Post-Infection Protection in the Hospital Staff of Three Prague Hospitals: A Cohort Study of 8-Month Follow-Up from the Start of the COVID-19 Vaccination Campaign (COVANESS)

Continuous assessment of the effectiveness of approved COVID-19 vaccines is crucial to gain an insight into the longer-term impact on health outcomes, and eventually boosting public confidence. For this reason, we conducted a multicenter, retrospective cohort study using data on infection and vaccination rates among employees of three Prague hospitals in the period between 27 December 2020 and 31 August 2021. The post-vaccination and post-infection protectiveness were assessed in a total of 11,443 hospital workers who were followed up for more than 14 days either after their Comirnaty vaccination or study enrolment, depending on their previous SARS-CoV-2 infection. The effectiveness of full vaccination against any SARS-CoV-2 infection achieved 88.3% (83.2-91.8%) over the eight months of follow-up, a figure not much different from the 92.5% (76.5-97.6%) level of protection built by a previous infection. Despite this, the post-vaccination level of protection declined to about 65% between June and August. No case of breakthrough infection was registered among hospital workers having received one or two vaccine doses more than three months after previous infection. The eight-month effectiveness of the Comirnaty vaccine exhibited a declining trend requiring a new booster dose. The need for vaccination in the previously infected employees was not demonstrated conclusively in this study.