Real-Time Monitoring of the Effectiveness of Six COVID-19 Vaccines against Laboratory-Confirmed COVID-19 in Hungary in 2021 Using the Screening Method

Abstract

Several studies have reported the waning effectiveness of COVID-19 vaccines. This study aims to demonstrate the applicability of the screening method for estimating vaccine effectiveness (VE) in a pandemic. We report VE in Hungary, estimated with the screening method, in 2021, covering a period of Alpha and the Delta variant, including the booster dose roll-out. Hungary is in a unique position to use six different vaccines in the same population. All vaccines provided a high level of protection initially, which declined over time. While the picture is different in each age group, the waning of immunity is apparent for all vaccines, especially in the younger age groups and the Sinopharm, Sputnik-V, and AstraZeneca vaccines, which performed similarly. This is clearly reversed by booster doses, more prominent for those three vaccines, where the decline in protection is more evident. Overall, two vaccines, Pfizer/BioNTech and Moderna, tend to produce the best results in all age groups, even with waning immunity considered. Using the screening method in future pandemic waves is worthwhile, especially in countries struggling with a lack of resources or when there is a need to deliver VE results within a short timeframe due to urgent decision-making.

Class switch towards spike protein-specific IgG4 antibodies after SARS-CoV-2 mRNA vaccination depends on prior infection history

“…The most widely applied types of vaccines against SARS-CoV-2 range from inactivated vaccines to non-replicating viral vector vaccines and recently introduced mRNA vaccines 2 . For primary immunizations, mRNA vaccines such as BNT162b2 by Pfizer-BioNTech, (hereafter Pfizer-BioNTech) and mRNA-1273 by Moderna (hereafter Moderna), vector-based vaccines such as ChAdOx-1 by AstraZeneca (hereafter AstraZeneca), Sputnik V by Gamaleya (hereafter Sputnik), Janssen by Johnson&Johnson (hereafter Janssen) and inactivated vaccines such as BBIBP-CorV by Sinopharm (hereafter Sinopharm) were introduced in Hungary, where 61.6% of the total population was fully vaccinated by the end of December 2021 3 .…”

“…To maintain high specific antibody levels, booster vaccination was introduced by August 2021, and 32.7% of the whole population in Hungary received at least one dose of a booster vaccine. As booster vaccines, Pfizer-BioNTech, Moderna, AstraZeneca, Janssen, or Sinopharm were applied 3 .…”

Vaccine Effectiveness against GP-Attended Symptomatic COVID-19 and Hybrid Immunity among Adults in Hungary during the 2022–2023 Respiratory Season Dominated by Different SARS-CoV-2 Omicron Subvariants

“…There is considerable variation in COVID-19 vaccine uptake between countries, which in turn affects the level of SARS-CoV-2 transmission. In Hungary, the COVID-19 vaccination programme started at the end of 2020, using a unique vaccine portfolio of six types of monovalent COVID-19 vaccines [12]. By week 20 of 2023, the cumulative uptake of the primary course of COVID-19 vaccination among the Hungarian population aged 18 years old and older was 71.5%, 11% lower than in the EU/EEA countries.…”

“…In Hungary, the third COVID-19 booster was administered starting from week 36 of 2022 and reached a cumulative uptake of 0.2%, which is 2.7% lower than the EU/EEA average [13]. The most commonly used booster vaccines in Hungary were mRNA vaccines [12].…”

Application of the screening method for estimating COVID-19 vaccine effectiveness using routine surveillance data: Germany’s experience during the COVID-19 pandemic, July 2021 to March 2023

“…The 'screening' or 'case coverage' method (hereafter referred to as screening method) has been successfully applied to estimate effectiveness of influenza [2][3][4][5] or pneumococcal [6] vaccines by using routine disease surveillance and vaccine coverage data. While at the beginning of the pandemic it was unclear how well suited this method would be for estimating COVID-19 VE, a number of countries [7][8][9] successfully implemented its use early on and the World Health Organization (WHO) provided guidance for its use in June 2022 [10].…”