Adult Immunisation in Clinical Practice: A Neglected Life Saver

L. Sophia, Sai Soundarya, Reshma Raju, G. Dominic Rodriguez*

*Correspondence:

Adult Immunisation in Clinical Practice: A Neglected Life Saver

Background

In a developing country like India, infectious diseases (ID) are an important reason for an enormous disease burden, causing morbidity, mortality and disability [1]. Infectious diseases can occur in people belonging to all age groups, whatever be their immune status [2]. Those with weakened immune responses, particularly children and patients with chronic illness like diabetes, are vulnerable [2]. Vaccination has been successfully used in prevention of infectious diseases and in promoting health. Besides protecting the individual from health hazards, vaccination also decreases healthcare utilization and preserves economic productivity [3].

The prevalence of vaccine preventable diseases (VPD) has significantly increased in the adult population. There is a major gap in awareness among general adults about vaccinations, which are still considered to be primarily for children. Incomplete and insufficient vaccination against VPD leads to health expenditure on treatment and hospitalization, and avoidable morbidity and mortality.

A high burden of vaccine-preventable diseases, increasing elderly population, immune senescence, and emerging drug resistance emphasize the need for robust adult immunization in India [4]. While immunization guidelines from various societies exist, there is inefficient implementation of the same. The reduced societal acceptance of adult vaccination also reflects the poor implementation and inadequate coverage. Specific recommendations exist for immunizing adults with comorbid conditions, such as lung disease and chronic kidney failure. Moreover, the recent guidelines emphasize on earlier administration of certain vaccines to avoid the risk of disease and complications.

Past

Vaccinations are recommended during life to prevent VPDs and associated complications. In the early-mid 20th century, demographics of the world comprised more of younger, growing populations. Also, various national vaccination programs were being framed and implemented for the first time. Hence, the focus was on childhood vaccination. Also, due to the high infection rate of VPDs in infants and children, childhood immunisation remained the norm [5].

Present

The prevalence of VPDs has significantly increased in the adult population. Statistics suggest that, in the United States, every year, significant number of adults experience severe diseases and are hospitalized due to VPDs [6].

There has been a significant shift in the prevalence, affected age groups, and susceptibility towards infectious diseases. Many diseases, earlier known as diseases of childhood are now affecting the adult population as well. In India, there is a lack of epidemiologically reliable estimates about the burden of communicable diseases. [7] Among several diseases affecting India’s health system, VPDs are most prominent. In a developing nation like India, the number of deaths due to infectious diseases is much more compared to deaths due to non-communicable diseases. A US-based study has brought forth various barriers to adult immunization such as lack of physician recommendations, misguided perceptions such as vaccinations are not necessary for healthy people, concerns regarding adverse effects, fear of injection, the nonexistence of insurance coverage, as well as adherence issues such as lack of an effective reminder system.

Unfortunately, there is an insignificant reach of vaccination in Indian adults. The economically viable adult population is not able to take the full benefit of protection against VPDs due to several factors.

There are many challenges in adult vaccination. Adults are engrossed in their life and ignore their health status or visit a doctor’s clinic for long durations. Often, or even invariably, they do not have a primary care physician too. Their health priorities are to get immediate relief, and they ignore the long-term health benefits.

Another problem is that there is a major gap in awareness among general adults about vaccinations which are still considered to be primarily for children. A survey found out lapses in awareness among patients and physicians, including unawareness among almost 80% of adults about adult vaccination, lack of recommendations for adult vaccines by general physicians or family doctors. A probable reason for this may be attributed to a lack of recommendations and clinical guidelines for adult immunization in India with very few physicians recommending vaccines for their adult patients. Both the physicians and patients harbour suspicions and ambiguous perceptions about the need, efficacy, and safety of adult vaccines [7].

The changing demographics of the adult, geriatric population and the growing cost of healthcare maintenance is a matter of concern in developing countries like India. Hence, it is vital to focus medical attention on promoting a healthy lifestyle which includes prevention, early detection, and management of various diseases and disorders. The elderly population is more susceptible to infections due to age-related decline in their immunity-termed as immuno- senescence. Moreover, the presence of one or more comorbid conditions in the elderly, such as cardiovascular diseases, pulmonary disorders, diabetes mellitus, chronic kidney disease renders them more vulnerable to infectious diseases [2]. The increasing proportion of elderly globally has introduced the concept of “healthy aging.” The World Health Organization (WHO) recognizes vaccination throughout an individual’s life as a significant component of healthy aging [8].

The widespread coverage of adult vaccination that was made possible, following availability of a vaccine against COVID-19 infection, shows that 100% prevention of VPDs can be achieved. Various associations and medical fraternities in India have come up with guidelines for adult immunization schedules in India. However, there is a definite need for a broad consensus on the vaccination.

Future

Current Recommendations for Adult Vaccination: Importance of Risk-Based Stratification

The vaccines recommended for all healthy adults in India are influenza (>50 years), pneumococcal vaccine (>65 years), human papillomavirus (9-26 years), Zoster (>60 years), DPT and MMR vaccines [9] (Table 1). Apart from vaccination for healthy adults, the Advisory Committee on Immunization Practices (ACIP) recommends vaccines based on risk [10]. High-risk individuals are those >65 years of age, pregnant women, healthcare workers working under high-risk conditions, patients with coronary heart disease or emphysema, diabetes, certain immunocompromised diseases such as HIV/AIDS, congestive heart failure, heart attack, angina, arrhythmia, chronic obstructive pulmonary disease, bronchitis, asthma, hepatitis B, hepatitis C, cirrhosis, chronic liver disease, and moderate to severe renal disease and current smokers. (Table 2-4).

At-risk individuals include those predisposed to certain medical conditions, such as laboratory staff, dialysis staff, nurses working in intensive care units and operation theatres and other surgeons and doctors, who are occupationally exposed to infectious diseases, such as hepatitis B and varicella-zoster.

Table 1. Recommended Adult Immunization Schedule by Age Group.

Table 2.Vaccines in comorbidities

Recommended vaccines for CKD patients on HD	Recommended vaccines for immunocompromised patients	Recommended vaccines for CLD patients	Recommended vaccines for diabetic patients	Recommended vaccines for splenectomy patients	Recommended vaccines for patients with heart or lung disease, alcoholism
Inactivated influenza vaccine	Inactivated influenza vaccine	Inactivated influenza vaccine	Inactivated influenza vaccine	Inactivated influenza vaccine
Tdap or Td	Hepatitis B	Tdap or Td	Tdap or Td	Tdap or Td	Tdap or Td
MMR	Pneumococcal vac	MMR	MMR	MMR	MMR
Varicella	Tdap or Td	Varicella	Varicella	Varicella	Varicella
HPV	MMR	HPV	HPV	HPV	HPV
Pneumococcal Vac 13	Herpes Zoster vaccine	Pneumococcal vac 23	Pneumococcal 23	Pneumococcal vaccine 13	Pneumococcal 23
Pneumococcal Vac 23			Hepatitis B	Pneumococcal vaccine 23
				H. Influenza
				Meningococcal vaccine

Table 3.Vaccine in specific groups

Recommended vaccines for adolescents	Recommended vaccines for elderly	Recommended vaccines for pregnant women	Recommended vaccines for healthcare professionals
Typhoid	Influenza	Influenza	Influenza
Tdap or TD	Tdap or TD	Tdap	Typhoid
HPV	Hepatitis B	Hepatitis B	Tdap
Meningococcal vac	Pneumococcal vac		Hepatitis B
			MMR

Table 4.Recommended Adult Immunization Schedule by Medical Condition or Other Indication

Conclusion

The current deficit in adult vaccine coverage is attributed to lack of awareness and knowledge about the benefits of vaccination, uncertainties about costs and benefits, low vaccine effectiveness in the elderly, accessibility and inconsistent recommendations by the healthcare providers (HCPs) [8]. In the aging population, evolving vaccines, lack of awareness in patients and providers, economic burden, lack of insurance coverage, vaccine delivery problems, and lack of adequate adult vaccination centres add to the existing challenges. Concerted efforts are required to improve the awareness of public and HCPs regarding VPDs and the benefits of adult vaccination and address the issue of low coverage. Stepwise, consistent and coordinated efforts at multiple levels can successfully implement adult vaccination programs in the country.

References

[1] Verma R, et al. Adult immunization in India: Importance and recommendations. Hum Vaccin Immunother. 2015;11(9):2180-2.

[2] Bonanni P, et al. Focusing on the implementation of 21st century vaccines for adults. Vaccine. 2018;36(36):5358-65.

[3] Doherty M, et al. Vaccine impact: benefits for human health. Vaccine. 2016;34(52):6707-14.

[4] Ghia CJ, et al. Developing adult vaccination ecosystem in India: Current perspective and the way forward. health services research and managerial epidemiology. 2021;8:1-8.

[5] Doherty TM, et al. Adult vaccination as part of a healthy lifestyle: moving from medical intervention to health promotion. Ann Med. 2022;51(2):128-40.

[6] Lu PJ, et al. Awareness among adults of vaccine-preventable diseases and recommended vaccinations, United States, 2015. Vaccine 2022;35(23):Verma R, et al. Adult immunization in India: Importance and recommendations. Hum Vaccin Immunother. 2022;11(9):2180-2.

[7] Verma R, et al. Adult immunization in India: Importance and recommendations. Hum Vaccin Immunother. 2022;11(9):2180-2.

[8] de Gomensoro E, et al. Challenges in adult vaccination. Ann Med. 2018;50(3):181-192.

[9] CDC Guidelines Centers for Disease Control and Prevention.Recommended adult immunization schedule-United States, 2012. MMWR Morb Mortal Wkly Rep. 2012;57(2):188-95.

[10] Kim DK, et al. Advisory Committee on Immunization Practices. Recommended adult immunization schedule, United States, 2019. Ann Intern Med. 2019;170(3):182-92.

[11] Arulrhaj S, et al. Adult Immunization in India, Changing the immunization Paradigm, Wiley, 2021.

Authors’ Note

The aim of this article is to provide a readily accessible reference to the immunizations recommended in adults. The material is adapted from the excellent reference book, Adult immunization in India [11].

Vaccine Preventable Diseases

Commonly Available Vaccines (Types, Dosing And Indications):

Influenza Vaccine – Types

(1) Trivalent vaccine and Quadrivalent vaccine – Inactivated Influenza vaccine (IIV)

(2) Live attenuated Influenza vaccine (LAIV)

Beneficial in reducing complications, hospitalization and mortality in diabetics. It prevents acute respiratory infections.

Dosing

(1) IIV – Annual vaccine 0.5 cc IM

(2) LAIV- 1 dose in each nostril

Special Populations

(1) Adults more than 65 yrs. of age, with any chronic disease, ( heart failure, COPD,DM, obesity, CKD )

(2) Pregnant women and women 2 weeks after delivery

(3) Health care workers

(4) Nursing home and health care facility residents

Typhoid Vaccine – types

(1) Injectable typhoid conjugate vaccine – combination vaccine

(2) Vi antigen-based polysaccharide vaccine ( ViPS)

(3) Oral live attenuated Ty21a vaccine

Prevents Typhoid fever

Dosing

(1) TCV 0.5 ml single dose up to 45 years of age.

(2) ViPS vaccine 0.5 ml IM 2 weeks before potential exposure.

(3) Ty21a – 1 enteric coated capsule day 0, 2, 4 and 6 days 1 hour before meal completed 1 week before potential exposure.

Special population

(1) Professional food handlers

(2) Travelers

(3) Persons with direct exposure

(4) Clinical microbiology staff

Varicella Vaccine – Types

(1) Attenuated live VZV

(2) Single antigen form and in combination with MMR vaccine

Protects against varicella disease

Dosing

(1) 0.5 ml S/C anterolateral thigh or upper arm. 2 doses 6 weeks apart.

Special population

(1) Females in reproductive age group

(2) High risk for exposure

(3) Nephrotic syndrome

(4) CKD

Diphtheria Pertussis Tetanus – types

(1) Diphtheria vaccines – inactivated toxin

(2) Tetanus- diphtheria – Td

(3) Tetanus – diphtheria- acellular pertussis – TDaP

(4) Pertussis vaccine

whole cell vaccine – killed

acellular pertussis – combination vaccine

(1) Tetanus vaccine – Toxoid

Post exposure prophylaxis

(1) Those who completed primary vaccination schedule booster dose of Td vaccine every 10 years

(2) Adults not previously vaccinated – Td vaccine 3 doses, 1ST 2 doses in an interval of 4 weeks and third dose after 6 to 12 months.

Dosing

(1) 0.5 ml IM

Special populations

(1) Diphtheria – Pregnancy, HIV, high disease prevalence area, travelers

(2) Pertussis – Pregnancy, house hold contacts, health care workers

Tetanus- Pregnant, HIV, immunocompromised, wound

Hepatits A Vaccine – types

(1) Formaldehyde inactivated vaccines

(2) Live attenuated vaccines

Dosing

(1) Inactivated vaccine 0.5ml IM 2doses 6 to 12 months apart

(2) 0.5 ml live vaccine S/C single dose.

Special population

Travellers

Individuals needing lifelong treatment with blood products

Men having sex with men

People who work with HAV infected primates or HAV cultures in laboratory

Workers in contact with non-human primates

Injection users

CLD

Hepatitis B Vaccine -types

(1) Recombinant DNA

(2) Plasma derived

(3) Inactivated subunit vaccine

Dosing

(1) 1 ml IM 0, 1 and 6 months

(2) Special populations

(3) Healthcare workers

(4) Exposure

(5) Diabetes

(6) CKD

(7) HIV positive and immunocompromised

(8) Non immunized travellers

(9) Pregnant

Human Pappilloma Virus – types

(1) Quadrivalent vaccine – recombinant DNA

(2) Bivalent vaccine – purified L1 structural protein

(3) Non valent vaccine

Dosing

(1) 0.5 ml IM 3 doses 0 ,1, 6 months

Special population

Immunocompromised

HIV

Hemophilus Influenza – types

(1) Conjugate vaccine

(2) Available as monovalent vaccine or in combination with DPT and Hepatitis B

Dosing

(1) 0.5 ml intramuscular injection single dose

Special conditions

Functional or anatomic asplenia

HIV infected

Immunoglobulin deficient

Early component complement deficient

(1) Recipients of a hematopoietic stem cell transplant

MENINGOCOCCAL VACCINE -types

(1) 2 Forms- polysaccharide and conjugate vaccine

(2) Available as monovalent or quadrivalent vaccine

Dosing

(1) 0.5 cc subcutaneous injection 2 doses one month apart

(2) <16 years- 2 doses; >16 years single dose

Special population

People who have CSF leaks or ear implants

Travellers

Residents of school hostels and military establishments

Lab workers, immunocompromised individuals

STREPTOCOCCUS PNEUMONIA vaccine – types

(1) 23 valent pneumococcal polysaccharide vaccine (PPSV 23)

(2) Conjugate vaccine

a. 10 valent pneumococcal conjugate vaccine (PCV 10)

b. 13 valent pneumococcal conjugate vaccine (PCV 13)

Dosind

(1) 0.5 ml single dose IM

(2) < 65 years PCV 13 is recommended in series in 8 weeks with PPSV 23

(3) > 65 years PCV 13 followed by PPSV 23 at an interval of 2 to 6 months and repeated after 5 years with PPSV 23 .( in immunocompromised patients the booster is given in 1 year itself )

(4) Note : pneumo 13 is given only once followed by pneumo 23 as boosters

Special population

Age > 65 years

CSF, leak patients, ear implant and asplenia patients

CKD, COPD, Diabetes, Cirrhosis, HIV, Lupus, Cancer

MMR – vaccine types

(1) Live attenuated vaccine

(2) Monovalent form or in combination with rubella, mumps or varicella vaccines

Dosing

(1) 0.5ml S/C 2 doses with in a gap of 28 days

(2) 26 to 55 years

(3) Contraindicated > 65 yrs., pregnancy, immunosuppressed states

Herpes Zoster – vaccine types

(1) Available as Recombinant or live vaccine

(2) Dosing: 0.5 ml S/C

(3) Recombinant vaccine – 2 doses at an interval of 2 to 6 months

(4) Live vaccine-single dose

Special conditions

Age > 50 yrs., CKD, DM, RA, COPD

Recommended vaccines for patients undergoing elective splenectomy

(1) Pneumococcal vaccine Pneumo 13 followed by Pneumo 23-8 weeks later

(2) Hi b – H influenza B vaccine

(3) Meningococcal quadrivalent vaccine 2 doses 8 weeks apart

This set of vaccines ideally started 8 – 10 weeks prior to surgery or started 2 weeks after surgery in emergency splenectomy patients.

Dr. G. Dominic Rodriguez

General Physician

Adult Immunisation in Clinical Practice: A Neglected Life Saver