Interim Public Health Considerations for COVID-19 Vaccination Rollout During 2023

Severe COVID-19 continues to disproportionately affect older adults and individuals with underlying medical conditions. With each new wave of infections, surveillance data for EU/EEA countries from 2022 onwards show hospital, intensive care unit (ICU) admissions and deaths in the age groups 65–79 and 80+. shows the greatest increase. However, the peak heights of these indicators are lower than in the pre-Omicron period. Similarly, length of hospital stay increases with age, being longest in individuals aged 65 and over, especially her 80 and over.

At this stage of the pandemic, the primary objective of the COVID-19 vaccination campaign remains to reduce hospitalizations, severe illness and death from COVID-19, and protect health systems.

In 2022, all EU/EEA countries recommended COVID-19 booster doses, mainly for older age groups aged 60 and over, individuals with underlying medical conditions, and other selected groups . For those aged 60 and over, primary series and first booster intakes were flat across all countries last year (over 90% and over 40%, respectively). The second booster uptake shows a less clear pattern and more heterogeneity across countries. In general, uptake rates decrease with each subsequent booster dose added to a vaccination campaign.

Despite only a minority of infections being detected, reported COVID-19 case rates have fluctuated at levels comparable to those reported in late 2020 and into 2021. This suggests an ongoing high level of SARS-CoV-2 transmission in the EU/EEA and therefore vulnerable to severe COVID-19. This suggests that there is a higher risk of exposure in this group.

A predictable seasonal pattern for COVID-19 has not yet been established. Nonetheless, the time series of severe COVID-19 outcomes (hospital, ICU admissions, and COVID-19 deaths) since the beginning of the pandemic have been similar to those associated with illness during the period corresponding to the traditional influenza season. This indicates that the impact of

Subvariants of the Omicron SARS-CoV-2 virus continue to dominate the EU/EEA and global SARS-CoV-2 virological landscape. In the EU/EEA, there has been a proportional increase in XBB.1.5, other XBB lineages, and several variants under investigation (VUI), including CH.1.1, with no epidemiologic deterioration expected by 2023. By March 2015, XBB.1.5 had become the dominant lineage. situation.

According to data reported in the EU/EEA (18 country reports), bivalent vaccines targeting Omicron substrains BA.1 and BA.4/BA.5 will not be administered after September 2022. accounted for approximately 94% of the total vaccine dose delivered.

Currently available data on vaccine efficacy (VE) for monovalent and bivalent booster doses indicate additional protection against severe outcomes in previously vaccinated individuals. For the most part, bivalent BA.4/5 mRNA COVID-19 vaccine studies were conducted during a period when Omicron BA4/5 or Omicron variant substrains were the dominant strains. For bivalent vaccine efficacy, longer follow-up is needed to determine the long-term protective effect of bivalent boosters on severe outcomes.

Evidence suggests that hybrid immunity provides strong protection against severe COVID-19, with high levels of protection likely lasting 12 months or more. However, hybrid immunity is likely not developed uniformly across populations, and reportedly has the lowest incidence among the elderly.

ECDC based mathematical modeling on the epidemiology of COVID-19 observed in EU/EEA countries, booster vaccination observed in EU/EEA countries, review of the literature on vaccine efficacy, decline and hybrid immunity. is taking place. In the main analysis, the scenarios modeled for campaigns restricted to once or twice a year and for the 50+ and 80+ population, respectively, are presented below.

• Fall 2023 Immunization Campaign In an optimistic scenario of high vaccination coverage among individuals aged 60 years and over, the target group would be an estimated 21–32 cumulative COVID-19-related hospitalizations across all EU/EEA countries by 28 February. It is expected to prevent % . Year 2024. The increment of prophylaxis is greater if individuals aged 60+ are targeted instead of 80+. The protective effect is similar whether the subject is over her 50s or over her 60s.
• combine Fall 2023 Immunization Campaign For those over 60 years old In the spring 2023 vaccination campaign Targeting individuals over the age of 80 may significantly increase the impact of vaccination (estimated 36-44% reduction in hospitalization). But only if the vaccine intake is high in both the fall and spring campaigns. Low vaccination coverage in the Spring 2023 campaign followed by high vaccination coverage in the Fall 2023 campaign in the same age groups (80 and 60 years respectively) differs only slightly from the Fall 2023 campaign alone. This indicates that achieving high vaccination coverage is critical for the spring campaign to be effective at the population level.
• Similar results were observed for preventable mortality and disability-adjusted life years (DALYs).
• Contrasting the overall impact with the efficiency of different vaccination campaign scenarios, the effectiveness per dose increases with the age of the target population. However, comparing the fall and spring campaigns, we don’t see much difference in efficiency.

Four EU/EEA countries have now published their approaches/recommendations for the 2023 COVID-19 vaccination campaign. nursing home). Towards autumn vaccination, two countries have announced campaigns targeting vulnerable groups, including those aged 65 and over and those with underlying medical conditions.

Based on the factors summarized above, in order to reduce the impact of COVID-19 and the associated hospitalizations and mortality expected during 2023, countries should promote the availability of COVID-19 vaccines, especially during the fall/winter season. You should plan for continued deployment. Consider the following points:

• Immunization efforts should focus on protecting people over the age of 60 and vulnerable individuals of all ages, including those with underlying medical conditions and those who are immunocompromised, in the fall and winter of 2023. there is.
• To maximize protection for individuals, consideration should also be given to offering COVID-19 vaccination to individuals aged 80 and over and other vulnerable adults, regardless of age, in spring 2023. If uptake is projected to be high, this could also have a significant impact at the population level.
• For fall/winter vaccination campaigns, countries should consider combined vaccination campaigns against COVID-19 and influenza. This approach can be more efficient in terms of management, logistics and costs.
• If you conduct a spring COVID-19 vaccination campaign, you should allow sufficient time between the spring and fall campaigns.
• The above considerations are in line with the current epidemiological scenario of the WHO Strategic Advisory Group of Experts on Immunization (SAGE), which defined high, medium and low priority groups for continuing COVID-19 vaccination. ) are consistent with the recent highlights presented by In its updated roadmap highlights, SAGE will be administered to high-priority groups with an additional dose 6 or 12 months after the last dose, with a time window dependent on factors such as age and immunocompromised status. A booster dose is recommended. SAGE indicates that these recommendations should not be considered a continuous annual COVID-19 vaccine booster for him.
• Overall, national-level decisions related to COVID-19 vaccination in 2023 will depend on the epidemiological situation of a particular country, the potential for viral evolution, vaccine availability (including updated vaccines), It will continue to depend on many important evolutionary factors, such as vaccine efficacy. and long-term protection, evidence for efficacy of repeated boosters, degree of hybrid immunity across populations, projected vaccine uptake in different age groups, vaccine acceptance, and associations with other competing public health priorities. The capacity of the health system to deliver a vaccine in Post-pandemic stage.
• Encouraging acceptance and dissemination of COVID-19 vaccination is becoming more difficult as public interest in vaccination wanes and the perception of ‘back to normalcy’ increases. Factors leading to reduced uptake need to be identified, even in previously vaccinated populations. For future vaccination campaigns, consider developing targeted communications, focusing on reaching high-priority groups through trusted channels and messengers to identify which groups are recommended to be vaccinated and when available. may consider providing clear information on the type and timing of vaccines for We also need to remind people why it is important to be up to date on immunizations (especially those in his severe COVID-19 risk group).