Abstract
BACKGROUND/AIMS
Epidemics of vaccine-preventable diseases (VPDs) are a growing concern worldwide; they have a significant and pervasive impact on individuals, as well as on public health and healthcare systems and the economy. People of all ages are affected by VPDs. Despite awareness and relatively good vaccination rates (VCR) in childhood, adult VCR are insufficient in our country, as in many countries.
MATERIALS AND METHODS
In this manner, we conducted a comprehensive population-level cohort study to evaluate the awareness, attitudes, and behaviors of a population aged over 18 years of age about adulthood vaccination. This is a cross-sectional, survey-based study that was conducted between July 2023 and September 2023 using a structured questionnaire and was carried out in Nicosia, the North Cyprus. A total of 960 surveys were analyzed, of which 67.92% were female and 32.08% were male.
RESULTS
It was determined that there was a statistically significant difference in the rates of adulthood vaccination according to the participants’ age groups, gender, place of birth, professions, marital status, health status, and continued medication use (p<0.05). Adulthood VCRs of those aged ≤25, females, high-school graduates, and single were low, whereas those of Turkish citizens, healthcare workers, people with comorbidities, and who constantly use medication were high. Furthermore, it was statistically significant that knowledge about recommended adulthood vaccination and the protection provided by those vaccinations was high among those working in healthcare services (p<0.05).
CONCLUSION: The awareness level regarding adulthood vaccinations is insufficient. With vaccination, the incidence and mortality of VPDs in adults can be reduced and even reached the point of elimination, as observed for some childhood diseases. Reasons for non-vaccination should be addressed, and effective measures should be determined and taken to overcome these obstacles.
INTRODUCTION
A vaccine is a suspension of weakened viruses, bacteria, or their antigenic fragments that is given to the body primarily to prevent diseases by conferring active and passive immunity.1
Immunization with vaccines is one of the best health investments, saving millions of lives each year. It is the main defense against serious, preventable, and sometimes fatal, contagious diseases. It is safe and cost effective.2-5
People of all ages are affected by vaccine-preventable diseases (VPDs);6 however, most vaccination policies target infants and children.3 More than 100 million children worldwide are vaccinated each year; despite this awareness and relatively good vaccination rates in childhood, adult vaccination rates (VCR) are insufficient.3-9
Outbreaks of VPDs are a worldwide growing concern; they have a marked and widespread impact on public health as well as on individuals and thus on healthcare systems and the economy.10, 11 Globalization causes the quicker spread of infectious diseases because of the rapid mobility of people across borders.5 Life expectancy increases logarithmically,9 as morbidities increase with aging, and adults become more susceptible to infectious diseases; complications and mortality also increase with age too.6, 7, 12The immunity provided by childhood vaccination decreases (immunoscence). We should also take into account low vaccination coverage and the possibility of incomplete vaccination programs in childhood. There is a clear need for developing and implementing protective strategies13 for aging. The coronavirus disease-2019 (COVID-19) pandemic has highlighted that preventive measures should be lifelong.6
The benefits of vaccination exceed those for those who are vaccinated to those who cannot (because of immune deficiencies, age or contraindications, etc.) by reducing the chance of physical contact between infected and vulnerable (herd immunity).2, 14 Furthermore, vaccination not only decreases transmission but also reduces the number of deaths, hospitalizations, incidence among risky groups of the population, functional losses, disabilities, antimicrobial resistance, socioeconomic issues, and the labor force.
Studies generally focus on adults aged over 65 years. Even if it is not enough, VCRs over 65 years have improved; however, younger adults who are at risk remain low. In our country, as in many others, most adults have not been vaccinated against adult VPDs.6It is important to understand the reasons for low uptake and barriers to effective vaccination, and awareness of the need for adult vaccination should be raised to make it a part of routine care.
In this manner, we conducted a comprehensive, population-level cohort study to evaluate the awareness, attitudes, and behaviors of the population aged over 18 years about adulthood vaccination. The secondary objective was to assess the impact of the COVID-19 pandemic on vaccination awareness and rates.
MATERIALS AND METHODS
This was a cross-sectional, survey-based study that was conducted between July 2023 and September 2023 using a structured questionnaire aiming to determine vaccination coverage, knowledge, and behaviors regarding adulthood vaccination. The referent population included healthcare professionals (doctors, dentists, nurses) and adults aged >18 years.
The questionnaire consisting of 27 questions was distributed both as an online questionnaire and a printed version; participants were carefully instructed to complete it only once. The self-report questionnaire was administered using Google Forms and disseminated using instant messaging apps (e.g., Whatsapp, Viber), social media (e.g., Facebook, Instagram), and institutional emails to doctors, nurses, and dentists currently working in the Turkish Republic of North Cyprus (TRNC). A printed version of the questionnaire was offered to patients admitted to Near East University Hospital as outpatients to the Department of Internal Medicine. The questionnaire was a self-administered questionnaire that captured information under the following sections: 1) demographic characteristics, 2) knowledge regarding adulthood vaccinations, routinely recommended vaccines in the guidelines before and after the COVID-19 pandemic, beliefs about vaccination, 3) vaccination status, and reasons for choosing to get vaccination or not.
Ethical approval for this study was obtained from the Scientific Research Ethics Committee of Near East University (approval number: YDU/2022/108-1663, date: 30.11.2022). Informed consent was obtained from all participants.
Statistical Analysis
The Statistical Package for the Social Sciences 26.0 software was used to statistically analyze the data obtained in this study. The distribution of participants according to their sociodemographic characteristics, general health and smoking status, information, awareness, and attitudes about adulthood vaccination were determined by frequency analysis. The chi-square test2 was used for the univariate analysis of the effect of each factor on the vaccination status of the participants. Descriptive statistics were generated for each question in the survey. The confidence intervals with a p value of less than 0.05 were considered for inclusion in the multivariable logistic regression model.
RESULTS
A total of 960 surveys were analyzed in our study. 652 (67.92%) of the participants were female, and 308 (32.08%) were male. In the 960 surveys, the socio-demographic characteristics of the participants (Table 1), their distribution according to their health status and smoking status (Table 2), the distribution of some characteristics regarding information on adult vaccines are shown (Table 3), and Table 4 shows the participants included in the study. Pearson X2 test results are given to compare the adult vaccination status according to the sociodemographic characteristics of the participants. It was determined that there was a statistically significant difference between the rates of vaccination in adulthood according to the participants’ age groups, gender, place of birth, profession, marital status, health status, and continuous medication use (p<0.05). It was observed that the adult vaccination rates of those aged 25 years and under, women, high school graduates, and single individuals were low. Turkish citizens, healthcare workers, people with chronic diseases, and people who constantly use medication had high adult vaccination rates.
In Figure 1, participants’ awareness about adult vaccines and vaccine protection is compared according to their professions. According to our study, it was statistically significant that knowledge about recommended adulthood vaccination and the protection provided by those vaccinations was found to be higher for those who work in healthcare services (p<0.05).
DISCUSSION
In this study, we aimed to reveal the awareness, attitudes, and behaviors of adults living in TRNCs regarding adult vaccination. This is the first time such a study has been conducted in the general population living in the study area. As in other studies conducted for the same purpose in various countries, adult VCRs were not found satisfactory. In a study published by Uthoff et al.14 in 2023, annual influenza vaccination rates were far from the recommended rates, and the rates for pneumococcal, Herpes Zoster, and other available vaccines were even lower. In this study, we found that 96.98% of the participants received the COVID-19 vaccine, 46.88% received another vaccine other than COVID after age 19, 66.44% received tetanus, 42.89% received influenza, and 38.44% received hepatitis B vaccine. The pneumococcal vaccination rate was very low and ranked 5th (7.78%).
Only ¼ of the participants in our study considered themselves at risk for diseases requiring adult vaccination. A total of 21.46% of people had an opinion about the protection of adult vaccines. Adult VCR was found to be high in risk groups such as those working in the healthcare field, those with chronic diseases, and those who constantly use medication, as expected. However, although awareness of adult vaccination among healthcare workers was generally high, the vaccination rate was not at the desired level. Thus, in their study among healthcare professionals in 2019, Evren et al.13 found that although the level of knowledge about influenza and pneumococcal vaccines was high, vaccination rates were low.
Vaccination is the most effective and safe preventive health service for preventing infectious diseases, and it is reported that VPD are becoming more common in adults, with an increase in both relative and real cases. The main reasons for this are explained by the decrease in immunity to vaccines over time, the lack of recommended booster vaccine doses in adults, and the existence of people who were incompletely vaccinated or never vaccinated during childhood. In addition, susceptibility to infectious diseases increases with the weakening of the immune system because of both aging and the increase in chronic diseases in adults.15However, interest in adult vaccinations and vaccination rates is quite low. E.g. none of the participants in Aşık et al.’s16 study received all adult vaccinations. Only 59% have received any adult vaccination at some point in their life. In North Cyprus, according to our study, 46.8% of people have received an adult vaccine other than the COVID vaccine, where the application rates of childhood vaccines are very high both in Türkiye and in our country.17 Likewise, while the rates of childhood vaccinations are very high in Western countries, those in adults are quite low for reasons such as knowledge gaps, fear of side effects, concerns about their effectiveness, and the perception of not being in the risk group.18, 19
According to our study, the most common reasons for the low rates of adult vaccinations can be listed as the rates of those who had information about side effects and vaccine protection were low (21.8-21.4%), and only 24.6% of our participants considered themselves at risk for diseases that can be prevented by adult vaccination. Although the adult vaccination rates of people with a chronic disease who constantly take medications and healthcare workers were higher than those of others, they were generally low. In many countries, adult vaccination is inadequately administered, similar to our results. It has been reported that even in developed countries, the VCRs for adults are low. However, immunization services must be continued in adulthood because adults are highly exposed to VPD in their working and social environments. In a study conducted on adults and elderly people aged over 18 years in Türkiye, it was found that 65% of the participants were susceptible to diphtheria, 569 were susceptible to tetanus, and 90% were susceptible to whooping cough. It was reported that 78% of the study participants needed a tetanus vaccine, 90% a whooping cough vaccine, and 96% a diphtheria vaccine.20 In our study, less than half of the participants had received another vaccine other than COVID-19 after the age of 19 years, and we found that 66.44% of them had had tetanus.
As is is known, flu can lead to common and serious diseases and even serious complications such as secondary bacterial pneumonia. Additionally, flu vaccination plays an indirect role in preventing invasive pneumococcal infection, which tends to occur during flu season.21However, among healthcare professionals, the rate of flu vaccination is not at the desired level. The flu vaccination rate among all participants was 42.8%.13
According to the CDC survey, 20% of people aged 65 years and older had received a flu vaccine and never received a pneumococcal vaccine. Some European countries have reported approximately 50% coverage for pneumococcal vaccination in high-risk populations. Most countries do not even report these rates. Some studies have shown that the most important obstacle to vaccination is that most high-risk patients are not even aware of it. This study also showed that advice from healthcare professionals is the most important factor for being vaccinated.22
Therefore, healthcare providers play a critical role in informing patients about vaccination.23 Several studies have shown that the provision of vaccines by healthcare professionals is an independent predictor of pneumococcal and influenza vaccine uptake in the elderly.24 These data demonstrate that the education of healthcare professionals indirectly refers to the education of society. The vaccination rate of healthcare workers in the United States is over 75%, but in many European countries it is below 30%.25
Vaccination has been an important issue among both the public and healthcare professionals since March 2020, when the COVID-19 outbreak was declared a pandemic by the World Health Organization.26 TRNC is a defection-dependent republic with a population of 350,000, located in the Eastern Mediterranean. After the first case of COVID-19 was identified in March 2020, a combination of precautions taken on time by the country’s council of ministers depending on science board decisions helped TRNC successfully control the first wave of the pandemic, and the country became COVID-19-free for about 2.5 months.29 During the period when we planned our study, our participants’ awareness, knowledge, and attitudes about the disease were quite good, thanks to the early and reliable information provided by both social media and healthcare professionals about COVID-19 infection. In our study, it was determined that 96.98% of the participants were vaccinated against COVID-19, whereas the percentage of participants who knew about adulthood vaccinations was 83.03% before the pandemic. Similar rates of COVID-19 have been reported in studies from other countries. The general level of knowledge about both the symptoms of the disease and ways to prevent it is quite high, and awareness and vaccination rates were found to be even higher, especially among hospital employees.7, 27, 28
Most of those who received adult vaccinations were men between the ages of 36-45. Adult vaccination rates were found to be high for those who were T.R. nationals, had higher education levels, were constantly taking medications, and were working in healthcare services.
Study Limitations
There are some limitations to our study: firstly, most of the participants were reached through an online survey; most of them were living and working in the city center. We did not have the opportunity to reach people with different educational and social statuses in rural areas. Therefore, it may not be appropriate to generalize the results to the entire population. Second, only awareness and attitudes about adult vaccination were investigated. Application and methods to prevent diseases were not examined. Third, since the period in which our study was conducted was during the COVID-19 epidemic, all attention was focused on the epidemic; other adulthood vaccines or preventable diseases were more in the background. The study results may have differed if it was conducted before pandemic.
CONCLUSION
Adulthood immunization is a current and important issue all over the world. We tried to show that adulthood vaccination awareness among the adults living in TRNC is not enough, similar to many countries, even in healthcare facilities, and is not taken into account as needed. In our study, we demonstrated that education is crucial for awareness and continuation. In order to be protected from preventable diseases, it is necessary to develop immunization programs with an understanding of lifelong immunization, activate public resources to finance this service, and provide regular active training to raise awareness among healthcare professionals and the public. Moreover, the issue of vaccine hesitancy and even vaccine rejection, which is increasing all over the world, should be handled carefully, and protecting public health should be a high-level goal. With vaccination, the incidence and mortality of preventable diseases in adults can be reduced, and these diseases can be brought to the point of elimination, as in some childhood diseases. Reasons for non-vaccination should be addressed, and effective measures should be determined and taken to overcome these identified obstacles.
MAIN POINTS
• Increase of awareness attract attention to the importance of vaccination among adults.
• Vaccination may provide a decrease in the incidence and mortality of VPDs in adults as in some childhood diseases.
• Addresing the reasons for non-vaccination help to overcome the obstacles thus leading to an increase in the vaccination rates.
