ADULT VACCINATIONS

Let me begin with a confession that it is embarrassing for a pediatrician to write about ‘‘Adult’’ vaccinations. But I suppose, you all will agree that vaccination is a topic predominantly in the domain of pediatrics and hence this venture! Here I wish to give youjust a flavor of the topic rather than a comprehensive write up.

Adult vaccination is an incredibly important but hugely neglected, underrated and under publicized topic, more so in India. The uptake of adult vaccinations is worryingly low.

When was the last time you encountered adult vaccination? Probably an international traveler or a pregnant woman. In an era when we are so particular about childhood vaccinations, we should be perturbed by miserably poor coverage of vaccinations in adults.

Many of us invest good amount of effort, time and money on healthy eating and exercising as a means to keeping ourselves healthy and fit but fail to visualize vaccinationas a tool for achieving the same goal. In fact, vaccination is the simplest, most effective and least expensive modality of preventive healthcare for adults. Vaccines are the most impactful medical innovation of the twentieth century. Let us clear the fog around this topic by answering five questions.

HOW IMPORTANT IS ADULT VACCINATIONS?

Vaccination of adults is an important tool for preventing various infectious and non-
infectious diseases: -

1. Vaccine preventable diseases (VPD): Vaccines as we all know protects us from VPD like pneumonia (caused by  influenza virus including swine flu, pneumococcus etc.), hepatitis (A & B), CNS infections (meningitis, encephalitis) and so on. There are few diseases, initially thought to occur only in children, which are now a days seen with increased frequency in adults like pertussis, diphtheria and chickenpox and for all of these effective vaccines are available. Apart from escaping the morbidity andmortality of these diseases, adults save on loss of work days, cost incurred in treatment and likelihood of spreading it to near and dear ones in family and friends. Spread of infection to children and older people can be catastrophic at times.
2. Non-communicable diseases (NCD): Vaccines also have an important bearing on NCD like ischemic heart disease (IHD) and stroke. NCD have two-way relationship with VPD. Patients with NCD have higher risk of complications and death when they get VPD and VPD increase the risk of getting ischemic heart disease and stroke. VPD have pro inflammatory and pro coagulant effects which are responsible for vascular complications seen with it. Risk of getting IHD and stroke are less in vaccinated people as compared to non-vaccinated.
3. Cancers: Vaccines also protect from various cancers like liver, oral, penile, anal and
   cervical cancers.

Thus, as can be noted that apart from common knowledge of prevention of VPD,
vaccination have an additional benefit in regards to NCD and cancers. Looks like buy one,
get two free!

WHY ADULT VACCINATION IS SUCH A NEGLECTED ISSUE?

I will walk you through some factors which can explain as to why adult vaccination is not
so popular amongst doctors and patients alike: -

1. Lack of awareness and low prioritization of adult immunization.
2. Lack of Universal program of immunization (UPI): unlike in children, Government of India has no UPI for adults.
3. Fear of injections (Believe me!).
4. Misconceptions: People are skeptical of vaccine efficacy and side effects in spite of the fact that vaccines are generally safe and effective. Various myths, like vaccines weakens Immunity system, people with good Immunity don’t need vaccines and adults who did take vaccines in childhood don’t need them when they get old, are detrimental to vaccine uptake rates of population.
5. Regulatory and professional apathy towards immunization of adults.

WHICH ADULTS NEEDS VACCINATIONS?

1. All healthy adults need vaccinations.
2. High Risk population: people with comorbidities & chronic diseases like heart diseases, lung diseases (Asthma , COPD), diabetes, liver disease, kidney disease, obesity, age more than 65 years, healthcare workers, lack of previous vaccination, immunocompromised states and alcoholism have higher risk of complications and death from VPD. Also VPD can lead to decompensation of their primary illness. For them getting vaccinated is all the more important.
3. Pregnancy: vaccination of pregnant women not only protects mother but also the baby. Every pregnant woman should receive Flu and Tdap vaccines.
4. International travelers: as per schedule and requirements of individual countries. 

WHAT IS THE ROLE OF ADULT VACCINATION IN CORONA PANDEMIC?

Adult vaccination is important at all times but present pandemic has reignited our interest in this topic. Pandemic had some negative impact even on childhood vaccinations due to supply chain disruptions, population movement restrictions and reduced availability of healthcare professionals. All vaccines should be regularly given to adults as per recommendations during pandemic. Coinfection with other viruses and bacteria can increase morbidity and mortality of COVID-19 patients and vaccines have significant role to play in preventing these coinfections. Some studies have documented coinfection rates of 30-50% in COVID 19 patients. 

WHICH VACCINES ARE TO BE GIVEN TO ADULTS?

Various vaccines recommended for adults are influenza, Tdap, pneumococcal, MMR, Hepatitis A & B, Typhoid, Chickenpox, meningococcal, Human papilloma virus vaccines etc. Herpes zoster vaccine is also important for adults but presently not available in India. Recommendation from various Indian and international medical bodies, number of doses, vaccine schedule is depicted in the following table.

There is an urgent need to sensitize policy makers, professionals and population at large about adult vaccination. To make it long term, sustainable and impactful, we need to integrate immunization of adults into our concept of healthy living and healthy ageing. I wish we all take up adult vaccination with the seriousness it deserves and make it an indispensable part of preventive healthcare of adults, though this subject is likely to excite a sense of urgency among the converted and skepticism among the dubious. 

REFERENCES

1. Guidelines API. Executive Summary: The Association of Physicians of India. Evidence-Based Clinical Practice Guidelines on Adult Immunization. Expert Group of the Association of Physicians of India on Adult Immunization in India. JAPI. 2009; 57:345-56.
2. Sharadha K. The Grown-ups Vaccines. Published: 05th February 2014. Available from http://www.newindianexpress.com/cities/bangalore/The-Grown-ups%E2%80%99-Vaccines/2014/02/05/article2038944.ece[Google Scholar]
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4. Centre for disease control, CDC. Adult Immunisation schedule 2020, 19 years of age and above: https://www.cdc.gov/vaccines/schedules/downloads/adult/adult-combined-schedule.pdf.
5. Adult immunization in India: Importance and recommendations. Ramesh Verma, Pardeep Khanna, Suraj Chawla. Human Vaccine Immunotherapy. 2015Sep; 11(9): 2180–2182. doi: 10.4161/hv.29342. PMCID: PMC4635930.
6. Indian J Nephrol. 2016 Apr; 26(Suppl 1): S7–S14. PMCID: PMC4928530
7. Resham Dash, Ashish Agrawal, Vasant Nagvekar, Jayesh Lele,2020. Towards adult vaccination in India: a narrative literature review, Human Vaccines & Immunotherapeutics, 16:4, 991-1001,DOI: 10.1080/21645515.2019.1682842.
8. Co-infection with respiratory pathogens among COVID-2019 cases. Xiaojuan Zhu, Yiyue Ge, Tao Wu, Kangchen Zhao. Virus Research, Volume 285, 2020, Article 198005.
9. Infection and Risk of Ischemic Stroke. Stroke. 2003;34:452–457.
10. Infection is a risk factor for ischaemic heart disease and stroke and impacts long-term mortality: Carter P, Uppal H, Bainey K, et al. Heart 2018;104:A17-A18