Vaccinations for the Older Adult

Impact of influenza vaccination history in the clinical course of older adults hospitalized with COVID-19

BACKGROUND AND PURPOSE

Some studies have shown that influenza vaccination is associated with a lower risk of SARS-CoV-2 infection; in patients with COVID-19 infection, admission to intensive care is reduced, with less need for mechanical ventilation, shorter hospital stays, and reduced mortality. This study aimed to determine if a history of annual influenza vaccination impacts the clinical course of SARS-CoV-2 infection during hospitalization.

METHODS

This was an observational, prospective, cohort study of patients older than 65 admitted to the COVID-19 unit from January to June 2021. The history of influenza vaccination over the last 5 years was assessed in each patient during hospitalization. We measured the length of hospital stay, the need for admission to the intensive care unit (ICU), the patient's oxygen requirements, complications during hospitalization, and outcome (medical discharge or death). Patients with a history of vaccination against SARS-CoV-2 were not included.

RESULTS

We analyzed 125 patients, 50.4% (n=63) with history of influenza vaccination and 49.6% (n=62) without a history of influenza vaccination. In-hospital mortality was 44.8%, higher in the unvaccinated (54.8%) population (p=0.008). ICU admission was 27% higher in vaccinated (35%) patients (p=0.05). Patients without a history of influenza vaccination had a higher prevalence of cardiac (8% vs. 5%, p=0.04) and renal complications (29% vs. 13%, p=0.02). Patients with a history of vaccination had a greater need for invasive mechanical ventilation (25.4%, p=0.02).

CONCLUSION

In this study, a history of influenza vaccination in older adults with SARS-CoV-2 infection was related to lower in-hospital mortality.

Roadmap for Sex-Responsive Influenza and COVID-19 Vaccine Research in Older Adults

Sex differences in the immune system are dynamic throughout the lifespan and contribute to heterogeneity in the risk of infectious diseases and the response to vaccination in older adults. The importance of the intersection between sex and age in immunity to viral respiratory diseases is clearly demonstrated by the increased prevalence and severity of influenza and COVID-19 in older males compared to older females. Despite sex and age biases in the epidemiology and clinical manifestations of disease, these host factors are often ignored in vaccine research. Here, we review sex differences in the immunogenicity, effectiveness, and safety of the influenza and COVID-19 vaccines in older adults and the impact of sex-specific effects of age-related factors, including chronological age, frailty, and the presence of comorbidities. While a female bias in immunity to influenza vaccines has been consistently reported, understanding of sex differences in the response to COVID-19 vaccines in older adults is incomplete due to small sample sizes and failure to disaggregate clinical trial data by both sex and age. For both vaccines, a major gap in the literature is apparent, whereby very few studies investigate sex-specific effects of aging, frailty, or multimorbidity. By providing a roadmap for sex-responsive vaccine research, beyond influenza and COVID-19, we can leverage the heterogeneity in immunity among older adults to provide better protection against vaccine-preventable diseases.

Sex-specific effects of aging on humoral immune responses to repeated influenza vaccination in older adults

Older adults (≥65 years of age) bear a significant burden of severe disease and mortality associated with influenza, despite relatively high annual vaccination coverage and substantial pre-existing immunity to influenza. To test the hypothesis that host factors, including age and sex, play a role in determining the effect of repeated vaccination and levels of pre-existing humoral immunity to influenza, we evaluated pre- and post-vaccination strain-specific hemagglutination inhibition (HAI) titers in adults over 75 years of age who received a high-dose influenza vaccine in at least four out of six influenza seasons. Pre-vaccination titers, rather than host factors and repeated vaccination were significantly associated with post-vaccination HAI titer outcomes, and displayed an age-by-sex interaction. Pre-vaccination titers to H1N1 remained constant with age. Titers to H3N2 and influenza B viruses decreased substantially with age in males, whereas titers in females remained constant with age. Our findings highlight the importance of pre-existing immunity in this highly vaccinated older adult population and suggest that older males are particularly vulnerable to reduced pre-existing humoral immunity to influenza.

Barriers to Vaccination Among People with Parkinson's Disease and Implications for COVID-19

BACKGROUND

Patients with Parkinson's disease (PD) are at higher risk of vaccine-preventable respiratory infections. However, advanced, homebound individuals may have less access to vaccinations. In light of COVID-19, understanding barriers to vaccination in PD may inform strategies to increase vaccine uptake.

OBJECTIVE

To identify influenza and pneumococcal vaccination rates, including barriers and facilitators to vaccination, among homebound and ambulatory individuals with PD and related disorders.

METHODS

Cross-sectional US-based study among individuals with PD, aged > 65 years, stratified as homebound or ambulatory. Participants completed semi-structured interviews on vaccination rates and barriers, and healthcare utilization.

RESULTS

Among 143 participants, 9.8% had missed all influenza vaccinations in the past 5 years, and 32.2% lacked any pneumococcal vaccination, with no between-group differences. Homebound participants (n = 41) reported difficulty traveling to clinic (p < 0.01) as a vaccination barrier, and despite similar outpatient visit frequencies, had more frequent emergency department visits (31.7% vs. 9.8%, p < 0.01) and hospitalizations (14.6% vs. 2.9%, p = 0.03). Vaccine hesitancy was reported in 35% of participants, vaccine refusal in 19%, and 13.3% reported unvaccinated household members, with no between-group differences. Nearly 13% thought providers recommended against vaccines for PD patients, and 31.5% were unsure of vaccine recommendations in PD.

CONCLUSION

Among a sample of homebound and ambulatory people with PD, many lack age-appropriate immunizations despite ample healthcare utilization. Many participants were unsure whether healthcare providers recommend vaccinations for people with PD. In light of COVID-19, neurologist reinforcement that vaccinations are indicated, safe, and recommended may be beneficial.

Infectious Diseases in Older Adults of Long-Term Care Facilities: Update on Approach to Diagnosis and Management

The diagnosis, treatment, and prevention of infectious diseases in older adults in long-term care facilities (LTCFs), particularly nursing facilities, remains a challenge for all health providers who care for this population. This review provides updated information on the currently most important challenges of infectious diseases in LTCFs. With the increasing prescribing of antibiotics in older adults, particularly in LTCFs, the topic of antibiotic stewardship is presented in this review. Following this discussion, salient points on clinical relevance, clinical presentation, diagnostic approach, therapy, and prevention are discussed for skin and soft tissue infections, infectious diarrhea (Clostridium difficile and norovirus infections), bacterial pneumonia, and urinary tract infection, as well as some of the newer approaches to preventive interventions in the LTCF setting.

The public health value of vaccination for seniors in Europe

Longer life expectancy and decreasing fertility rates mean that the proportion of older people is continually increasing worldwide, and particularly in Europe. Ageing is associated with an increase in the risk and severity of infectious diseases. These diseases are also more difficult to diagnose and manage in seniors who often have at least one comorbid condition (60% of seniors have two or more conditions). Infectious diseases increase the risk of hospitalization, loss of autonomy and death in seniors. Effective vaccines are available in Europe for infectious diseases such as influenza, pneumococcal diseases, herpes zoster, diphtheria, tetanus and pertussis. Their effectiveness has been demonstrated in terms of reducing the rates of hospitalization, disability, dependency and death. The prevention of diseases in seniors also results in savings in healthcare and societal costs each year in Europe. Despite the availability of vaccines, vaccine-preventable diseases affect millions of European citizens annually, with the greatest burden of disease occurring in seniors, and the medical and economic benefits associated with are not being achieved. Vaccination coverage rates must be improved to achieve the full benefits of vaccination of seniors in Europe.

[Immunizing is not only a children's matter! : Why vaccinations are also important for adults]

Vaccinations belong to the ten most effective public health achievements worldwide. While immunization programms for children are installed in Europe, vaccinations for adults are not established. However, adult vaccination is extremely meaningful: increasing age means a higher susceptibility to infectious diseases, health problems and multimorbidity will increase. The burden of vaccine-preventable diseases is still high in Europe. Due to immunosenescence (older) adults are less protected against pathogens, antibody titers after vaccinations are lower and immunity lasts shorter. There is striking lack of data of adult vaccination rates and an international consensus regarding adult vaccination recommendations or guidelines are not available in Europe. In only six countries a comprehensive document describing recommended vaccinations for adults is available, among them Austria. The awareness of the importance of adult vaccination over the whole lifetime is not present to the necessary extent in Europe and has to be promoted.

Travellers and influenza: risks and prevention

BACKGROUND

Influenza viruses are among the major causes of serious human respiratory tract infection worldwide. In line with the high disease burden attributable to influenza, these viruses play an important, but often neglected, role in travel medicine. Guidelines and recommendations regarding prevention and management of influenza in travellers are scarce. Of special interest for travel medicine are risk populations and also circumstances that facilitate influenza virus transmission and spread, like travel by airplane or cruise ship and mass gatherings.

METHODS

We conducted a PUBMED/MEDLINE search for a combination of the MeSH terms Influenza virus, travel, mass gathering, large scale events and cruise ship. In addition we gathered guidelines and recommendations from selected countries and regarding influenza prevention and management in travellers. By reviewing these search results in the light of published knowledge in the fields of influenza prevention and management, we present best practice advice for the prevention and management of influenza in travel medicine.

RESULTS

Seasonal influenza is among the most prevalent infectious diseases in travellers. Known host-associated risk factors include extremes of age and being immune-compromised, while the most relevant environmental factors are associated with holiday cruises and mass gatherings.

CONCLUSIONS

Pre-travel advice should address influenza and its prevention for travellers, whenever appropriate on the basis of the epidemiological situation concerned. Preventative measures should be strongly recommended for travellers at high-risk for developing complications. In addition, seasonal influenza vaccination should be considered for any traveller wishing to reduce the risk of incapacitation, particularly cruise ship crew and passengers, as well as those participating in mass gatherings. Besides advice concerning preventive measures and vaccination, advice on the use of antivirals may be considered for some travellers.