=Paper=
{{Paper
|id=Vol-2962/paper25
|storemode=property
|title=Options for Optimizing Slovak National Vaccination Strategy
|pdfUrl=https://ceur-ws.org/Vol-2962/paper25.pdf
|volume=Vol-2962
|authors=Vladimír Nosáľ,Martin Smatana,Martin Šuster
|dblpUrl=https://dblp.org/rec/conf/itat/NosalSS21
}}
==Options for Optimizing Slovak National Vaccination Strategy==
https://ceur-ws.org/Vol-2962/paper25.pdf
Options for optimizing Slovak national vaccination strategy
Vladimír Nosáľ1, Martin Smatana2, Martin Šuster3
1
Department of Neurology, Jessenius School of Medicine in Martin, Comenius University, Martin, Slovakia
2
Ministry of Education, Science, Research and Sports, Bratislava, Slovakia
3
Slovak Economic Society, Bratislava, Slovakia
Abstract: The national vaccination strategy has undergone groups up to 60 years, even if they have a chronic diagnosis.
several updates since its publication in December 2020. The According to the modified national vaccination strategy, these
original strategy assumes priority vaccination of health groups are expected to arrive at about halfway through the
professionals and other critical occupations and continues schedule, but their relative risk is average or lower despite the
with priority according to age. The strategy revised in January existence of a chronic diagnosis.
took more account of some chronic diagnoses, which were
Conclusions: The recent modifications of the national
elaborated in more detail in the March revision. Considering
vaccination strategy bring a significant improvement over the
limited supply of vaccine and high incidence of COVID-19
original strategy. However, we see opportunities for further
cases throughout witner and early spring 2021, it was vital to
optimization by considering the risks of more defined
find most optimal vaccination strategy to minimize avoidable
population groups, especially among groups of "younger
deaths. Despite the adjustments, there is (was), especially in
seniors" with co-morbidities, who could be preferred.
March 2021, an opportunity to reduce the relative mortality
Furthermore, the algorithm can be used to set most optimal
index we develop by a few percentage points, using available
vaccination strategy not only at national, but also at regional
data and resources.
level, up to the detail of individual GP practices. Similarly,
Methods: We normalize the overall risk of the population to developed model can be quickly and effectively used to select
the pre-vaccination status. The result is a relative mortality a risk group of the population and prioritize any type of
index that considers the impact of vaccination on the medical preventive action.
individual risk of death from Covid-19. When determining
Results of the paper were used by health insurance companies
risk groups, we consider the basic age groups, risks of some
to fine-tune their vaccination priorities in spring 2021.
professional or social groups and diagnoses that are according
to available studies linked to greater probability of
hospitalization and / or death. Altogether, 17 groups of
1 Objectives and introduction
diagnoses were used in the analysis, out of which five were Slovak COVID-19 vaccination strategy was published in
regarded as most at risk: acute cancer, dialysis patients, people December 2020 and has since undergone several adjustments.
with organ transplants, people with Down syndrome and The original strategy prioritized health professionals and other
COPD. Data on disease prevalence was taken from health critical occupations and continued with priority according to
insurance companies. This enabled a detailed analysis, age. Revised strategy from January changes this approach and
including regional and local implications. Only registered put greater priorities on chronic diseases, which were further
vaccines were considered for modelling. expanded in March updates. Yet, considering a lack of supply
Results: January modification of the vaccination strategy will of vaccines in spring 2021, further improvements could have
help reduce the risk of mortality on Covid-19 by about 1.5 %. been made to improve relative mortality index.
March update brings only a slight improvement. However, The aim of this paper is to present possible adjustments to
there is additional 1 % for further optimization. These Slovak national COVID-19 vaccination strategy.
changes can (could be) implemented during March to April,
especially given the still low vaccination coverage of older Our primary goal was to adjust strategy to reduce avoidable
age groups. mortality from COVID-19. The second objective was to
protect the country's critical workforce to fight the
Primary space for improvement is in the increase of priority pandemic. We consider a priority to vaccinate health
for combinations of the oldest groups of the population with professionals, although their relative risk of dying from
chronic diseases (groups among strong population years 60- Covid-19, although relatively high, is not always highest
80 years of age with combinations of chronic diagnoses). At among at-risk groups.
the same time, it is possible to slightly delay younger age
______________
Copyright ©2021 for this paper by its authors. Use permitted under
Creative Commons License Attribution 4.0 International (CC BY 4.0).
2 Methodology - autoimmune diseases with the administration of
immunosuppressants (ATC_L04)
We created a relative mortality index that considers the impact - diabetes (divided into E10 and E11)
of vaccination on the individual risk of death from Covid-19 - cardiovascular diseases - heart attack in 2020 and later
and compared it to each of the vaccination updates to (I21 and I22)
determine their efficiency. - cardiovascular diseases - other (I05 to I52)
- chronic kidney disease (N18)
Process of determining risk groups, relative risks, vaccination
priority settings and vaccination schedules are described in - osteoporosis (M80)
following sections. - Alzheimer's disease with dementia (F00)
- severe psychiatric disorders addressed in inpatient
2.1 Risk groups care
- TB and mycobacteriosis (A15-A19, A31)
When determining risk groups, we took into account the basic
age groups 16-44, 45-59, 60-64, 65-69, 70-74, 75-79, 80- We further aggregated these patients into larger groups. We
84, and 85 and over. Furthermore, we considered the tried to create groups of patients with similar risks, which
increased risk according to selected diagnoses and the risks of for practical reasons can be specifically addressed in
some professional or social groups. the vaccination strategy. We selected five critical diagnoses
that are the riskiest and should be addressed as a matter of
The basic distribution of risk is based on the history of deaths
priority: acute oncological diseases, dialysis patients, people
in Slovakia as of March 2021 (IZA, 2021; ŠÚSR,
with organ transplants, people with Down syndrome and
2021) In further calculations, we consider the distribution of
severe chronic obstructive pulmonary disease. These are
deaths in 2021, when the British strain B117 was already
relatively small groups of patients with a total of 75,000
widespread in Slovakia. Taking into account the size of each
people.
demographic group, the relative risks of mortality were
calculated. We aggregated other groups of diagnoses according to the
number of diagnoses per patient with one diagnosis (without
The risk of dying from Covid-19 for men is significantly
the five diagnoses and among cardiovascular diagnoses only
higher than for women. However, we did not consider it
with past infarction), two, three or more diagnoses (including
realistic to set different criteria for individual
all other cardiovascular diagnoses). We also aggregate age
sexes. Therefore, after aggregation, we use the following
groups according to the division mentioned above. The
relative risks:
resulting grouping is shown in Table 1. Cardiovascular
- Age group 45-59 is a reference group diseases, apart from recent heart attacks, type 1 diabetes (E10)
- Group 16-44 is only 0,10 multiple of risk compared to and bronchial asthma, are only considered in combination
the reference group (RR) with other diagnoses.
- Category 60-64 has 3,23-fold greater risk than RR
The size of risk groups is based on data publicly available as
- Category 65-69 has 5,33-fold greater risk than RR
of February 2020. The overall demographic data for Slovakia
- Category 70-74 has a 9,00-fold greater risk than RR
are as of 1 January 2020. The population structure may have
- Category 75-79 has 12,88-fold greater risk than RR
changed slightly, as the pandemic resulted in higher mortality,
- Category 80-84 has 20,81-fold greater risk than RR
especially among older groups, especially at the end of 2020.
- Category 85+ has a 25,43-fold greater risk than RR
We also considered the following chronic diagnoses, which
according to available sources have a significantly higher 2.2 Relative risk
risk (CDC, 2021; PHE, 2021; Semenzato et al. 2021).
The basic relative risks by age are based on current data on
- oncological - in active treatment (new cases per year, mortality from Covid-19 in Slovakia. We used the statistics of
diagnosis C00-C99) deaths on Covid-19 until 12.1.2021 (ŠÚSR, 2021). We also
- dialyzed (Z49) took into account the expected loss of life for each age
- transplantation (kidneys, heart, liver, pancreas, lungs - group. The risk of death from Covid-19 increases with age
diagnosis Z94) significantly faster than the average life expectancy for
- Down syndrome (Q90) each age group decreases. The order of risk as well as taking
- chronic obstructive pulmonary disease (severe forms: into account the potential loss of years of life remains the same
J44.00, J44.01, J44.10, J44.11, J44.80, J44.81, J44.90, - except for a group of 85+, which is due to the low life
J44.91) expectancy behind a group of seventy years old.
- bronchial asthma (J45)
- sickle cell disease (D57)
- oncological, in monitoring (C00-C97)
Number of patients in risk groups Age cohort
Diagnosis ICD-10 16-44 45-59 60-64 65-69 70-74 75-79 80-84 85+
Oncological, new patients as of 2020 C00-C97 2 219 7 291 4 644 4 422 4 302 3 690 2 776 1 821
Dialysis Z49 615 690 631 511 676 420 225 60
Transplantation of an organ Z94 869 1 134 486 382 216 105 51 27
Down syndrome Q90 493 55 3 4 0 0 0 0
COPD J44 3 590 7 017 5 221 6 328 5 429 4 294 2 840 2 203
Other chronic diseases - one diagnosis 56 524 45 379 15 163 12 982 6 426 4 204 2 749 2 997
Other chronic diseases - two diagnoses 39 707 95 054 63 254 76 477 65 337 49 319 32 308 24 797
Other chronic diseases - three + diagnoses 9 243 28 379 22 451 30 121 30 373 26 474 18 506 12 933
Without a diagnosis 2 058 452 918 450 248 060 198 178 118 482 71 343 41 649 38 738
Table 1: Number of people in each of used risk groups; Source: NCZI (2021); OECD (2019); own calculation
Age group 16-44 45-59 60-64 65-69 70-74 75-79 80-84 85+
Adjusted relative risk according to age 0,18 1,00 2,26 3,04 4,02 4,30 4,92 3,54
Table 2: Adjusted relative risk according to age; Source: IZA (2021); ŠÚSR (2021); own calculations
Age group 16-44 45-59 60-64 65-69
healthcare workforce 32 000 35 000 9 000 3 000
social care employees 5 000 4 800 1 200 0
social care clients 15 000 12 000 3 000 0
soldiers, police, critical infrastructure 15 000 15 000 0 0
teachers 24 000 24 000 6 000 2 000
Table 3: Number of selected professionals and social groups according to age Source; IZA (2021); ŠÚSR (2021); own calculations
Additional relative risk to the reference age group without diagnoses
one chronic disease 0,6
two chronic diseases 1,5
three and more chronic diseases 3
new oncological cases, dialysis, transplants, Down, COPD 5,15
healthcare workforce 7
social care employees 1,4
social care clients 1,05
soldiers, police, critical infrastructure 0,3
teachers 0,6
Table 4: Additional relative risk to the reference age group without diagnoses; own calculations; Source: Jarkovský et al (2021), Mutambudzi et al. (2021),
Semenzato et al (2021).
We assumed that paramedics, teachers, and social care
We recognize that taking life expectancy into account can be services staff does not suffer from combination of three or
morally questionable in the provision of health care - just as more chronic diseases. We assumed that they have a similar
disregarding it can be morally questionable. The resulting risk health status as the rest of the population. We assumed good
weights are shown in Table 2. health without chronic diseases for members of the uniformed
forces and employees of critical infrastructure. Soldiers
We also included selected groups of professionals and social and police officers were more involved in testing in Slovakia
groups (social care services clients under 65) who have an than in other countries, but at present the testing capacity has
increased risk of infection and death on Covid-19. Their increased so that systematic assistance from the armed forces
numbers and age distribution are given in Table 3. Additional is no longer so necessary. Therefore, we considered it
risk for groups of chronically ill and professions is further sufficiently realistic to take estimates of increased risk from
calibrated using studies by Jarkovský et al (2021), Semenzato the literature. The resulting relative risks to the 15-64 group
et al. (2021) and Mutambudzi et al. (2021), shown in Table 4. are then as follows in Table 5.
Relative risk / diagnosis extra risk 16-44 45-59 60-64 65-69 70-74 75-79 80-84 85+
Oncological, new patients as of 2020 4 0,76 3,27 6,39 8,31 10,08 9,94 10,93 8,43
Dialysis 4,2 0,79 3,40 6,65 8,64 10,48 10,34 11,37 8,76
Transplantation of organ 3,5 0,69 2,95 5,75 7,48 9,07 8,95 9,84 7,58
Down syndrome 16 2,59 11,13 21,73 28,24 34,27 33,80 37,16 28,65
COPD 3 0,61 2,62 5,11 6,64 8,06 7,95 8,74 6,74
Other chronic diseases - one diagnosis 0,6 0,24 1,05 2,05 2,66 3,23 3,18 3,50 2,70
Other chronic diseases - two diagnoses 1,5 0,38 1,64 3,20 4,15 5,04 4,97 5,47 4,21
Other chronic diseases - three + diagnoses 3 0,61 2,62 5,11 6,64 8,06 7,95 8,74 6,74
healthcare workforce 7 1,22 5,24 10,23 13,29 16,13 15,91 17,49 13,48
social care employees 1,4 0,37 1,57 3,07 3,99 4,84 4,77 5,25 4,04
social care clients 1,05 0,31 1,34 2,62 3,41 4,13 4,08 4,48 3,45
soldiers, police, critical infrastructure 0,3 0,20 0,85 1,66 2,16 2,62 2,58 2,84 2,19
teachers 0,6 0,24 1,05 2,05 2,66 3,23 3,18 3,50 2,70
others 0 0,15 0,65 1,28 1,66 2,02 1,99 2,19 1,69
Table 5: Final relative risk indices for age groups; Source: own calculations
Available data on patients contain relatively few people with In the alternative scenario, we simulated (i) the old national
obesity. Most diagnoses of E66 are recorded in children, adult vaccination strategy (ii) its updated version by decree of the
patients are rarely treated directly for obesity. In the data from Ministry of Health from 19th January 2021 that placed
National center for healthcare information (herein as “NCZI) higher prioritization on older people and the moved members
we see only 2 034 such persons. At the same time, the of the critical infrastructure into replacement group and (iii)
European Health Survey shows that more than 1% of the and currently valid version of the strategy, updated by decree
population has serious obesity with a BMI over 40, i.e. about of the Ministry of Health on 5th of March 2021 -
50,000 adults. However, as this is a visually obvious with prioritization, in particular according to age and without
diagnosis, possibly verifiable in a few seconds, we consider it priority for members of critical infrastructure.
sufficient for patients to present this diagnosis when
The table below also provides assumptions as to what part of
registering for vaccination, without the need for confirmation
a population will eventually be vaccinated. For most groups,
by the attending physician. Underweight (BMI below 18.5)
it is estimated as 70% (which will require
can also be considered, especially in combination with type 1
strong communication campaign, as currently
diabetes.
only about 55 % of the population wants to get a vaccine). For
members of critical infrastructure, we assume eventually
100% vaccination, similarly to social care staff and clients,
2.3 Priority setting where vaccination may eventually be introduced as a
In our basic model, the priorities for vaccination are based on condition of admission to the facility (similarly as vaccination
the Table 5, organized from the highest to the lowest risk. The against influenza is currently mandatory).
only change is in moving all health professionals to the
For health professionals and teachers - where there is a better
beginning of the schedule, in line with the objectives and
awareness of SARS-COV-2, we assumed 85% participation
in line with reality of vaccination in Slovakia. Given that the
in vaccination. Resulting prioritization of all 4 scenarios are
threat to the functioning of the economy is not that present in
shown in Table 6 below.
other professions due to sick leave and quarantine, we did not
increase the priority for critical infrastructure.
Priority
Priority Propority Priority
Estimated according
Relative according according accoridng to
Category Number vaccinatio to the
Risk to the to the first the latest
n rate original
model update update
strategy
healthcare workforce; 65-69 13,29 3 000 85% 1 1 1 1
healthcare workforce; 60-64 10,23 9 000 85% 2 3 2 3
Other chronic diseases - three + diagnoses; 80-84 8,74 18 506 70% 3 2 2 2
Other chronic diseases - three + diagnoses; 70-74 8,06 30 373 70% 4 3 2 3
Other chronic diseases - three + diagnoses; 75-79 7,95 26 474 70% 5 4 2 3
Other chronic diseases - three + diagnoses; 85+ 6,74 12 933 70% 6 1 1 1
Other chronic diseases - three + diagnoses; 65-69 6,64 30 121 70% 7 3 2 3
Onko + CHOCHP + Dialyz. + Transp. + Down S 6,15 75 740 85% 8 4 2 4
Other chronic diseases - two diagnoses; 80-84 5,47 32 308 70% 9 2 2 2
healthcare workforce; 45-59 5,24 35 000 85% 10 3 2 3
Other chronic diseases - three + diagnoses; 60-64 5,11 22 451 70% 11 1 2 1
Other chronic diseases - two diagnoses; 70-74 5,04 65 337 70% 12 4 2 3
Other chronic diseases - two diagnoses; 75-79 4,97 49 319 70% 13 1 1 1
Other chronic diseases - two diagnoses; 85+ 4,21 24 797 70% 14 3 2 3
Other chronic diseases - two diagnoses; 65-69 4,15 75 148 70% 15 5 2 4
Other chronic diseases - one diagnosis; 80-84 3,50 2 749 70% 16 2 2 2
Other chronic diseases - one diagnosis; 70-74 3,23 6 426 70% 17 4 2 4
Other chronic diseases - two diagnoses; 60-64 3,20 59 534 70% 18 3 2 3
Other chronic diseases - one diagnosis; 75-79 3,18 4 204 70% 19 4 2 3
social care employees; 60-64 3,07 1 200 100% 20 3 2 3
Other chronic diseases - one diagnosis; 85+ 2,70 2 997 70% 21 5 2 4
Other chronic diseases - one diagnosis; 65-69 2,66 12 756 70% 22 1 1 1
teachers; 65-69 2,66 2 000 85% 23 4 2 4
social care clients; 60-64 2,62 3 000 100% 24 4 3 4
Other chronic diseases - three + diagnoses; 45-59 2,62 28 379 70% 25 2 2 2
others; 80-84 2,19 41 649 70% 26 5 2 7
Other chronic diseases - one diagnosis; 60-64 2,05 14 271 70% 27 1 2 4
teachers; 60-64 2,05 6 000 85% 28 3 2 3
others; 70-74 2,02 118 482 70% 29 4 2 3
others; 75-79 1,99 71 343 70% 30 6 3 4
others; 85+ 1,69 38 738 70% 31 7 3 4
others; 65-69 1,66 194 733 70% 32 4 2 4
Other chronic diseases - two diagnoses; 45-59 1,64 88 250 70% 33 5 2 7
social care employees; 45-59 1,57 4 800 100% 34 1 1 1
social care clients; 45-59 1,34 12 000 100% 35 1 2 7
others; 60-64 1,28 230 472 70% 36 8 4 4
healthcare workforce; 16-44 1,22 32 000 85% 37 6 4 7
Other chronic diseases - one diagnosis; 45-59 1,05 42 131 70% 38 9 3 7
teachers; 45-59 1,05 24 000 85% 39 1 1 1
soldiers, police, critical infrastructure; 45-59 0,85 15 000 100% 40 10 1 7
others; 45-59 0,65 840 703 70% 41 10 4 7
Other chronic diseases - three + diagnoses; 16-44 0,61 9 243 70% 42 5 2 11
Other chronic diseases - two diagnoses; 16-44 0,38 38 306 70% 43 5 2 11
social care employees; 16-44 0,37 5 000 100% 44 1 1 1
social care clients; 16-44 0,31 15 000 100% 45 1 2 11
Other chronic diseases - one diagnosis; 16-44 0,24 54 530 70% 46 6 3 11
teachers; 16-44 0,24 24 000 85% 47 9 3 11
soldiers, police, critical infrastructure; 16-44 0,20 15 000 100% 48 11 1 11
others; 16-44 0,15 1 970 846 70% 49 11 4 11
Table 6: Prioritisation of vaccination, in 4 calculated scenarios; Source: own calculations
2.4 Vaccination schedule
For vaccination, we assumed deliveries according to publicly
available information published in daily press. We only took
1st dose
into account already approved BionNTech / Pfizer, Moderna P+M+AZ
and AstraZeneca vaccines. For the first two vaccines, we 30,000 7,000,000
2nd dose
expect a period between two doses of 4 weeks. For P+M+AZ+
AstraZeneca, we modelled a 10-week period between the two JJ
Together 6,000,000
doses. This vaccine is only for people under 70 years of age. If 25,000 2. dose
the model allows multiple vaccines to be administered at the
same time, BioNTech / Pfizer or Moderna will be used 5,000,000
first, followed by AstraZeneca. At the same time, we assumed 20,000
that from the supplied vaccines, a reserve for the second dose
is always left for those who have already received the first 4,000,000
dose. We also assume that all available vaccines will be used
15,000
without loss.
3,000,000
The amounts of published doses are used in the model so that
the delivered vaccine is consumed evenly before the next 10,000
delivery (postponing half of the vaccines to the 2nd dose). The 2,000,000
model did not include the Johnson & Johnson vaccine, but it
is relatively easy to expand it with this option. We have not 5,000
yet included it due to uncertainty about the delivery 1,000,000
schedule.
Uncertainty about vaccine supply assumptions is, of course, 0 0
great. Accelerating delivery would improve the results of our
model in all scenarios, as well as the approval of the
Astra Zeneca vaccine in all age groups, or possibly
others. The delay acts in the opposite direction. However, the Figure 2: Estimated daily vaccination rate; Source: own calculations March
qualitative results of the model remain unchanged. 2021
12,000,000
BioNTech/Pfizer Moderna 2.5 Simulation
Astra-Zeneca Johnson & Johnson
10,000,000 For each of the scenarios, we simulated the results as follows:
- Available vaccines were divided to groups according to
priority, until the group for each charged with the
8,000,000 expected coverage rate (as shown in Table 6). When a
quota was filled for a priority group, we moved the
vaccination to the next group in sequence.
- We only used AstraZeneca to people under 70 years of
6,000,000
age.
- The second dose was expected 28 days after the first
dose with mRNA vaccines or after 70 days with
4,000,000 AstraZeneca
- For persons vaccinated with the first dose we expected a
reduction in their level of risk and by 72 %. After a
2,000,000 second dose of the protections 99 % (Dagan et al. ,
2021) .
- This is how we adjusted the relative risk of people who
have already been vaccinated. We could then calculate
0
1/1/211/2/211/3/211/4/211/5/211/6/211/7/211/8/211/9/211/10/21
1/11/21
1/12/21 the total risk as a weighted sum according to the number
of people in each group and their original (Table 5) or by
Figure 1: Estimation of vaccine deliveries (doses); Source: own calculations
vaccination reduced relative risk.
March 2021
- We assumed that vaccination with one dose reduces the According to the modified national vaccination strategy, these
risk of transmitting the infection by 50% and increases groups are expected to arrive at about halfway through the
to 80% after the second dose. schedule, but their relative risk is average or lower despite the
- We normalized the overall risk of the population to the existence of a chronic diagnosis.
pre-vaccination status. The result was a relative
Our results should be taken as a threshold result, if it would
mortality index. This index considered in particular
be possible to mobilize all sensitive groups in the right
the impact of vaccination on the individual risk of death
order completely effectively. As in practice the vaccination of
of individuals in Covid-19. We also considered
some groups will be extended and members of critical
reducing the number of susceptible individuals after
infrastructure or members of less sensitive groups will be
vaccination. On the other hand, it is also likely that
vaccinated as substitutes, the decline of the curves will
society will respond by releasing the severity of
be slightly slower than shown in Figure 3. However,
measures and discipline of the population. We did not
qualitative differences will be maintained.
dare to estimate the resulting effect of these opposing
epidemiological factors. However, it is highly likely that For a better numerical comparison, we calculated the area
even by the end of 2021, collective immunity will not be under the curve from Figure 3. Since the curves are levelling
achieved, and the spread of the pandemic will not at about 1/3 of the original risk at the end of 2021 (which is
stop. understandable, as we assume that almost 30% of the
population cannot be vaccinated and vaccination efficiency is
4 Results not fully 100%), we calculate the content under the curve by
30.6.2021. Figure 4 shows that a modification of the
The result of the simulation is shown in Figure 3. We see that vaccination strategy of 19.1.2021 will help reduce the risk of
the modified national vaccination strategy is a significant step mortality on Covid-19 by about 1.5 % . However, we see
forward from the original strategy. The current version of the further room for optimization by about 1 %. These changes
strategy is only a slight improvement compared to January could have been implemented during March to
update. Vaccination will reach high-risk groups 85+, 80-84 April, especially given the still low vaccination coverage
and other senior groups of the population faster. However, of older age groups.
this strategy can be further optimized based on our
The use of these opportunities would require consideration of
results. Specifically, it is recommended to increase priorities
several criteria in determining order of vaccination
for combinations of the oldest groups of the population
and effective use of large data sources of our health
with chronic diseases (groups aged 60-80 with combinations
information systems, cooperation with the attending doctors
of chronic diagnoses) . At the same time, it is possible to
and flexible ordering system.
postpone slightly younger age groups up to 60 years, even if
they have a chronic diagnosis, or a combination of diagnoses
in the younger age groups.
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
1/1/21
1/2/21
1/3/21
1/4/21
1/5/21
1/6/21
1/7/21
1/8/21
1/9/21
1/10/21
1/11/21
1/12/21
Priority according to the model Propority according to the first update Priority according to the original strategy
podiel neočkovanej populácie (2 dávky) Priority accoridng to the latest update
Figure 3: Relative mortality according to modelled scenarios; Source: own calculations
70%
60%
60.4% 62.3% 63.7% 62.2%
50%
40%
30%
20%
10%
0%
Priority according to the model Propority according to the first Priority according to the original Priority accoridng to the latest
update strategy update
Figure 4: Reduction in relative mortality in all scenarios; Source: own calculations
Jarkovský, J., Benešová, K., Cerny, V. et al. (2021) Covidogram as
5 Conclusion a simple tool for predicting severe course of COVID-19: population-
Proposed modification of the national vaccination strategy based study. BMJ Open. London: BMJ Publishing Group, 2021, vol.
11, No 2, p. 1-7. ISSN 2044-6055.
brings a significant improvement over the original
strategy. However, we see opportunities for further IZA (2021) Inštitút zdravotných analýz: github COVID-19 data.
optimization by taking into account the risks of more defined https://github.com/Institut-Zdravotnych-Analyz/
population groups, especially among groups of "younger covid19-data
seniors" with co- morbidities who could be preferred. Taking
Mutambudzi M, Niedzwiedz C, Macdonald EB, et al (2021)
advantage of these opportunities requires better handling
Occupation and risk of severe COVID-19: prospective cohort study
of data on the health status of the population, which is already
of 120 075 UK Biobank participants. Occupational and
available to the public sector, as well as greater flexibility of
Environmental Medicine 2021;78:307-314.
the ordering system and cooperation with attending
physicians resp. patients' health insurance companies. NCZI (2021) Národné centrum zdravotníckych informácií: dávky
zdravotných poisťovní.
Our approach also allows for flexible division into multiple
http://www.nczisk.sk/Statisticke_vystupy/Tematicke_statisticke_vy
groups by age, occupation, or diagnosis - which proves to be
stupy/Pages/default.aspx
practical when opening vaccination options to other groups,
where we have observed the exhaustion of available OECD (2019). OECD/European Observatory on Health Systems and
dates within minutes. We also demonstrate that grouping by Policies. Slovak Republic: Country Health Profile 2019, State of
diagnosis is possible using existing data in NCZI Health in the EU, OECD Publishing, Paris/European Observatory on
databases. Therefore, it would not be necessary to request Health Systems and Policies,
confirmation from physicians from the vast majority of Brussels, https://doi.org/10.1787/c1ae6f4b-en.
patients with chronic diagnoses, automatic verification of the
PHE (2021) Public Health England: Guidance on shielding and
registration system in the NCZI database is sufficient.
protecting people who are clinically extremely vulnerable from
Furthermore, the algorithm can be used to set most optimal COVID-19.
vaccination strategy not only at national, but also at regional https://www.gov.uk/government/publications/guidance-on-
level, up to the detail of individual GP practices. Similarly, shielding-and-protecting-extremely-vulnerable-persons-from-covid-
developed model can be quickly and effectively used to select 19/guidance-on-shielding-and-protecting-extremely-vulnerable-
a risk group of the population and prioritize any type of persons-from-covid-19#cev
medical preventive action. Results of the model were used by
Semenzato, L., Botton, J., Drouin, J., Cuenot, F., et al. /2021)
health insurance companies to fine-tune their vaccination
Maladies chroniques, états de santé et risque d'hospitalisation et de
priorities in spring 2021 (i.e., creation of lists of patients with
décès hospitalier pour COVID-19 lors de la première vague de
chronic diseases which were sent to the National Health
l’épidémie en France: Étude de cohorte de 66 millions de personnes.
Information Center).
EPI-PHARE. https://splf.fr/wp-content/uploads/2021/02/Epiphare-
References Maladies-chroniques-Etat-de-sante-et-risque-hospitalisation-et-de-
deces-hospitalier-pour-COVID-19-66-millions-de-personnes-en-
CDC (2021) Centers for disease control and prevention. People
France-Mis-en-ligne-le-09-02-21.pdf
with Certain Medical Conditions.
https://www.cdc.gov/coronavirus/2019-ncov/need-extra- ŠÚSR (2021) Štatistický úrad Slovenskej Republiky.
precautions/people-with-medical-conditions.html DEMOGRAFIA – PRÍČINY ÚMRTÍ V SLOVENSKEJ
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Dagan, N., Barda, N., Kepten, E., et al. (2021) BNT162b2 mRNA
Covid-19 Vaccine in a Nationwide Mass Vaccination Setting. The
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