VACCINES
Vaccines are another topic that falls under the category of you do it for your car, why don’t you do it for yourself. You get an oil change and lube job regularly, right? Do you do that because your car is not working right? I hope not. You do it so you don’t have major car issues down the road. Same with tire rotation, changing the transmission fluid, etc. People do not get vaccinated because they are always sick. People get vaccines to prevent major illnesses down the road.
Now one thing that people need to understand with population medicine is this: Just because you get a vaccine does not mean you will not get sick. Also, just because you do not get a vaccine does not mean that you will get sick. Population medicine does not work that way.
In population medicine, if I were to take 10,000 people and give 5,000 a treatment and the other 5,000 no treatment, I would expect the 5,000 who got the treatment, in general, to fare better than the 5,000 that did not get the treatment. Otherwise, the treatment would not be recommended. That does not mean that some of the 5,000 treated might not get sick. Not all treatments work all the time in all patients. Some treatments have side effects, most mild but some potentially severe, that people not subjected to the treatment would not get. In addition, not everyone not subjected to the treatment would get the illness that the treatment is trying to prevent. However, if the group getting the treatment did not, overall, do better than the group not getting the treatment, the treatment would not be recommended.
That is how vaccines work. There are studies that show that the recommended vaccines, in general, promote better lifelong health than not getting vaccinated.
Since I am a general internist and treat adults, and that is the focus of my book, I am going to limit my discussion to vaccines recommended for adults.
The vaccines currently recommended on a regular basis for adults are:
Influenza vaccine
Tdap and tetanus vaccine
HPV vaccine
Pneumococcal vaccine
Shingles vaccine
Hepatitis A and Hepatitis B
MMR
Covid-19
RSV vaccine
The influenza vaccine is recommended yearly for all adults. The number of adults who get sick with influenza in the United States varies between 9,000,000 and 41,000,000 each year. Hospitalizations in the United States due to influenza vary from year to year. According to the Center for Disease Control and Prevention, during the 2019-2020 flu season, an estimated 400,000 adults were hospitalized due to influenza and complications associated with influenza in the United States. Now this varies associated with the severity and effectiveness of the current influenza strain and vaccine, but the number usually ranges from 140,000-710,000. The number of people in the United States who have died from influenza annually range from 12,000-52,000. These numbers are based on CDC data for the years 2010-2020.
Even ignoring the hospitalizations and deaths from influenza, a recent review showed that up to 75% of employees who had influenza missed work when they had the flu or flu like illness. Their average time out of work was 2-3 days each time they were sick. Most employees who had the flu or flu like illness also said that they worked while they were sick at some point, thus exposing coworkers to influenza. Most employed adults who were caregivers for someone else with the flu said that they missed work to care for someone else for an average of 1-2 days. Overall, people who were vaccinated against the flu missed less time from work compared to their peers who were not vaccinated. This review of published medical studies showed that the flu and flu-like illness have a meaningful impact on people’s ability to work, which also impacts their employers and society.
The effectiveness of the influenza vaccine can vary from year to year and is influenced by multiple factors including the match between the circulating flu strain and the strains included in the vaccine, the age and health status of the individual receiving the vaccine, and the individual’s immune response to the vaccine. This is why older adults, whose immune status is less, and certain other people with decreased immune function, will get a stronger version of the flu shot.
On average, the flu vaccine reduced the risk of getting the flu by about 40-60%. However, in some years, the effectiveness can be lower if there is a mismatch between the vaccine and the circulating strains. Even in cases where the vaccine does not prevent the flu, it can still help reduce the severity of the illness, complications, hospitalizations and deaths associated with the flu.
It is important to note that the flu vaccine needs to be updated each year to account for changes in the flu virus, so it is recommended to get vaccinated annually. The flu vaccine also provides protection against severe complications and reduces the spread of the flu to vulnerable populations.
The second vaccine that is recommended regularly is the tetanus/diphtheria (Td) vaccine. This is recommended every 10 years. A primary series is given in childhood to protect against three illnesses, tetanus, diphtheria, and pertussis. After that, a one-time booster of Tdap (tetanus diphtheria and pertussis) is recommended for all adults, and then Td. (Tetanus and diphtheria) every 10 years.
Tetanus is a potentially life-threatening bacterial infection caused by the bacteria Clostridium tetani, whose spores can be found in the environment in the soil, dust and animal feces and can enter the body through wounds or cuts. The bacteria produce a toxin that affects the nervous system and leads to muscle stiffness and spasm. The vaccine is recommended every 10 years to ensure that individuals have adequate levels of antibodies to neutralize the tetanus toxin if exposed.
Diphtheria is a highly contagious bacterial infection caused by Corynebacterium diphtheria. It primarily affects the respiratory system, causing a thick coating to form in the throat and nose, which can lead to difficulty breathing, heart problems and even death.
With universal vaccinations, seeing a case of tetanus or diphtheria is very rare today.
Pertussis, also known as whooping cough, is a respiratory infection caused by Bordetella Pertussis. It typically starts with cold-like symptoms such as a runny nose, sneezing, and mild cough. After a week or two the cough becomes more severe and frequent, leading to intense coughing fits. These fits can be exhausting and may cause vomiting or difficulty breathing or sleeping. The cough may be followed by a distinctive whooping sound as the person gasps for air.
The pertussis vaccine is usually administered as part of the combination vaccine Tdap, and is given to infants, children, adolescents and adults to protect against pertussis and reduce the risk of transmission to vulnerable populations, especially infants who are too young to be fully vaccinated.
The next recommended vaccine is the HPV vaccine. This vaccine protects against the human papillomavirus and is recommended for adults up to the age of 26, especially if they have not received it previously.
HPV can cause several illnesses, the most common of which include genital warts which occur on or around the genitals, anus or throat. These warts can be painful, itchy and may require treatment for removal. The other common illness HPV causes is cervical cancer. Persistent infection with high-risk HPV types can lead to changes in the cells of the cervix that can progress to cervical cancer if left untreated.
Other cancers HPV can cause include anal, vaginal, vulvar, penile and oropharyngeal, or the back of the throat.
It is important to note that while HPV is a common virus, most infections clear up on their own without causing any health problems. However, certain high-risk type of HPV can cause long-lasting infections that can lead to the development of these illnesses. Vaccination against HPV can greatly reduce the risk of infection and associated diseases.
Prevnar 20 is a vaccine that provides protection against certain strains of streptococcus pneumonia bacteria, which can cause pneumonia and meningitis. The Prevnar 20 basically replaces the combination of Prevnar 15 and pneumovax 23, which were given a year apart. The current recommendations are for all adults aged 65 to receive one dose of Prevnar 20. Certain organizations may recommend repeating every 5 years for people with emphysema or copd, but this is not a universal recommendation. In addition, adults between 19-64 who have certain medical conditions that make them susceptible to pneumococcal infections are recommended to get it prior to age 65. The list is too expansive to include here, but the most common conditions include those with diabetes mellitus, emphysema or copd, cochlear implants or CSF leaks.
Shingrix is a vaccine recommended for adults aged 50 and over to protect against shingles and its complications. This replaced Zostavax, which was a one dose vaccine. Shingrix was found to be more effective than Zostavax, (97% vs51%). Both vaccines lost effectiveness with advancing age. At age 70 , Zostavax was only 41% effective vs 89% for Shingrix. Shingrix can cause feverishness and muscle aches in about 20% of patients receiving it, meaning 80% do not get this side effect. In most cases acetaminophen or ibuprofen will relieve symptoms.
Shingles can be quite a devastating illness, causing severe pain which may last for up to months in many patients, so getting the vaccine can certainly prevent this debility.
Hepatitis B has a universal recommendation and is given to all infants currently in the United States. For those who were not immunized as a child, the recommendations stand as thus:
Catchup vaccination is recommended for those who are at higher risk of infection due to Hepatitis B, including adolescents and adults who have high risk sexual practices, injection drug use, healthcare workers, patients with HIV infection, being a household or sexual contact of someone with chronic hepatitis B, or being a traveler to regions with high hepatitis B prevalence. Patients with chronic liver disease or end stage kidney disease are also at risk of complications from hepatitis B infection and vaccination is recommended also.
Hepatitis A is currently a universal recommendation and is part of routine childhood vaccinations. For those not vaccinated as a child, catchup vaccination is recommended in people with increased risk of hepatitis A due to travel to regions with high hepatitis A prevalence, close contact with individuals infected with hepatitis A, patients with chronic liver disease, men who have sex with men, and individuals with clotting factor disorders.
MMR vaccine protects against measles, mumps and rubella. It is recommended for adults who have not been vaccinated or have not had the diseases before.
Varicella, or chickenpox, vaccine is recommended for adults in certain high-risk settings who have not had the vaccine prior nor had the illness. This group includes healthcare workers, college students, military personnel, correctional facility staff and international travelers.
The meningitis vaccine, or meningococcal vaccine is recommended in certain adults, including college students living in dormitories or other close-quarter settings, military recruits, individuals with a damaged spleen or whose spleen has been removed, those traveling to regions with high rates of meningococcal disease, especially sub-Sahara Africa and Saudi Arabia during Haji pilgrimage, and laboratory personnel who handle Neisseria meningitidis bacteria.
I am not going to get into the politics of the Covid-19 vaccine, but boosters are recommended currently. Studies have shown that for at risk patients, keeping up to date with boosters does decrease death rate and hospitalization rates for Covid-19 and complications related to it. This is especially true among the elderly, those with copd, heart failure, liver disease, and diabetes.
The last vaccine I am going to discuss is the RSV vaccine, for respiratory syncytial virus. This is a virus that can adversely affect both the very young and the very old. Since this book is for adults, I will limit my discussion to adults. It is currently recommended for all adults over 75, those with emphysema and or heart failure. It can also be considered for adults who will have exposure to newborns not yet vaccinated for RSV.