Michael Hunter, MD on Medika Life

Vaccination Roundup — What You Should Know

WITH THE COVID PANDEMIC, IT IS EASY TO FORGET about vaccines targeting other illnesses. Vaccines are increasingly on my mind as I approach 60, as I know I cannot fight off infections as well as I could when younger.

Are you up to date on boosters for COVID-19? What about tetanus, diphtheria, and pertussis (whooping cough)? Then there are hepatitis A and influenza vaccines.

Today, I want to discuss three vaccinations: influenza (flu), pneumonia, and shingles. And yes, I am up to date. Full confession: The shingles vaccine caused moderately severe pain at the injection site for several days.

Sufficient sleep and vaccine effectiveness

Could a good night’s sleep improve the effectiveness of your COVID-19 (and other) vaccines? Short sleep the day after a jab may not be an important issue for most of us who don’t have compromised immune systems.

However, if you have some compromise in your immune system’s ability to fight infectious disease, getting an adequate sleep duration during the night after the vaccination may enhance your chances of getting an adequate response to vaccines.

Photo by bruce mars on Unsplash

One research investigation discovered that ten days after vaccination for seasonal influenza, antibody levels in individuals getting a jab after four consecutive days restricted to four hours had half of the antibody levels of those without short sleep.

separate study showed sleep duration (measured with a device) associated with antibody responses to hepatitis B vaccination. Researchers examined 70 females, ages 40 to 60. All received a standard three-dose hepatitis B vaccination series.

The subjects wore devices to track sleep and completed sleep diaries. The researchers checked antibody levels before the second and third vaccinations. Finally, the study investigators checked antigen immunoglobulin status (to assess clinical protection status) at the six-month mark.

The lower antibody response associated with less sleep appeared independent of age, body mass index, sex, and response to initial immunization.

As measured by actigraphy devices, shorter sleep duration predicted a lower chance of being clinically protected from hepatitis B after the vaccination series. Subjective sleep quality did not prove a useful predictor of antibody response.

These studies hint that getting sufficient sleep during vaccination may boost immune system response, but there is no high-level evidence. The studies remind me to get a good night’s sleep around the time of my jabs.

Photo by Insung Yoon on Unsplash

Vaccination and time of day

Did you know that our immune systems have significant circadian rhythms? In this context, might the time of a vaccination affect efficacy?

Immune system basics

There is a circadian rhythm in the ability of immune system cells (lymphocytes) to enter and exit lymph nodes. Lymphocytes survey antigens by circulating through our bloodstream, and lymph nodes and lymph modulate our specific immune responses in nodes.

scanning electron microscope (SEM) image of a single human lymphocyte. https://en.wikipedia.org/wiki/Lymphocyte

In layperson language, lymphocytes are a white blood cell type and are an important part of our immune system. Approximately 20 to 40 percent of the white blood cells are lymphocytes. Here is an explanation of what lymphocytes do, courtesy of WebMD:

Lymphocytes are created in your bone marrow. We have B lymphocytes (B-cells) designed to make antibodies. Antibodies take out foreign substances or mark them for an attack. On the other hand, T-cells are lymphocytes that destroy any cells that cancers or viruses have invaded.

Natural killer cells are another lymphocyte type. NK cells can destroy tumor cells without any previous activation. In contradistinction, T-cells only attack a cell if another immune cell has tagged it.

Lymphocytes have memory, able to remember antigens — a toxin or other foreign substances that provoke our immune system to respond. Once the lymphocyte encounters an antigen, some become memory cells. The memory lymphocytes quickly respond when an antigen comes around for a second time. We take advantage of this immune response when we use vaccines.

Vaccination time during the day

Critical components of the immune system oscillate in humans and mice with opposite phases according to their inverted rest-activity times; I mean that circulating immune cells known as leukocytes are high during the rest periods — the night for humans and the day for mice.

One study of influenza and hepatitis A vaccination discovered that administering the vaccines in the morning (and not the afternoon) led to an almost two-fold higher immune system response in men (but not women), as measured by antibody levels four weeks later.

I do not believe we have anything actionable here, but interesting to learn about circadian rhythmicity and immune system function.

Influenza (flu) vaccination

Influenza vaccines can help protect us against the four influenza viruses that research suggests will be the most common during the upcoming flu season. While most receive a jab (typically in the upper arm), there are also nasal flu vaccines.

Flu is relatively common. 20average:

  • Five to 20 percent of the U.S. population will get the flu, on average, each year.
  • 200,000 Americans are hospitalized annually because of illness-related complications.
  • 8,200 to 20,000 people who die each year from flu-related causes in the United States.

The United States Centers for Disease Control (CDC) explains that:

“All flu vaccines for the 2022–2023 season are quadrivalent vaccines, designed to protect against four different flu viruses, including two influenza A viruses and two influenza B viruses. Different vaccines are licensed for use in different age groups, and some vaccines are not recommended for some groups of people.”

To learn more, please check out the CDC site:

Seasonal Flu Vaccines

Influenza (flu) vaccines (often called “flu shots”) are vaccines that protect against the four influenza viruses.


The CDC recommends that all six months and older in the USA get an influenza (flu) shot each season, with rare exceptions. Vaccination to prevent flu (and its potential associated complications) is especially important for those at higher risk of developing serious flu-related problems.

Is there a preferred type of flu shot? For some individuals, yes. For the upcoming 2022 to 2023 flu season, three types of flu vaccine are available for those at least 65.

Photo by Johnny Cohen on Unsplash

The preferred vaccine types for those 65 or older are Fluzone High-Dose Quadrivalent vaccine, Flublok Quadrivalent recombinant flu vaccine, or Fluad Quadrivalent adjuvanted flu vaccine. These vaccines may be more effective for this age group than regular flu vaccines. There is no preferential recommendation for people younger than 65 years.

How effective are flu shots?

When scientists get the vaccine right for any given flu season, the vaccine can drop the risk of having to go to the doctor because of flu by up to half or more (40 to 60 percent lower chance).

Moreover, the flu shot can drop influenza complication severity. A 2021 study revealed that among adults hospitalized with flu, vaccinated patients had a one-quarter lower chance of intensive care unit (ICU) admission and a nearly one-third lower risk of death from flu compared to the unvaccinated.

Flu vaccination is also associated with lower rates of some cardiac events among people with heart disease, particularly for those who have had a cardiac event in the past year. Flu can also reduce flu-related worsening of chronic lung diseases such as COPD (chronic obstructive pulmonary disease).

Honestly, I believe I am healthy enough to weather a flu infection. One of the primary reasons I will get the jab is to protect those around me, particularly those with a higher risk of serious flu-related complications.

My flu shot should help young children, older folks, and those with certain chronic health conditions around me. Fortunately, life-threatening allergic reactions to flu shots are quite rare.

Allergic to eggs?

The CDC explains that individuals who have an egg allergy are candidates to receive an age-appropriate flu vaccine that is otherwise appropriate.

Those with a history of a severe reaction to eggs should receive their vaccine in a medical center, with appropriate health professional oversight. Finally, there are two completely egg-free vaccine options: Flublok Quadrivalent recombinant flu vaccine and Flucelvax Quadrivalent cell-based flu shot.

Pneumonia vaccination

Why consider a pneumonia vaccine? While imperfect, the pneumonia vaccine can lower your chances of catching the disease. In addition, even if you get pneumonia, having had the vaccine can help drop its severity.

For the older amongst us or those who have health issues, a lung infection that makes it harder to breathe could be particularly problematic.

Here are some groups that should strongly consider pneumonia vaccination, according to WebMD:

  • Weakened immune systems. If you have heart disease, diabetes, emphysema, COPD, or asthma, you are more likely to have a weakened immune system, which makes you more likely to get pneumonia. Those who received an organ transplant, those with HIV or AIDS, and people receiving chemotherapy fit into this category.
  • People over 65
  • Smokers
  • Heavy drinkers of alcohol
  • Individuals getting over surgery or a severe illness. If you were in the hospital intensive care unit and needed a ventilator to help you breathe, you have a higher risk of getting pneumonia. Those recovering from major surgery or a serious injury also have a higher risk.

Who shouldn’t get a pneumonia vaccine?

Not everyone needs to get a pneumonia vaccine. You can probably skip the vaccine if you’re a healthy adult between 18 and 50. Also, you shouldn’t get it if you’re allergic to what’s in the vaccine. Not sure? Ask your doctor.

The United States Centers for Disease Control (CDC) recommends pneumococcal vaccination for all children under five years and all adults at least 65. In certain situations, others should get the vaccine. Learn more here:

Pneumococcal Vaccination: What Everyone Should Know

Pneumococcal disease is common in young children, but older adults are at the greatest risk of serious illness and deat.


Shingles vaccination

Shingles is a viral infection that can result in a painful (on occasion, extraordinarily so) rash. This skin rash can happen anywhere on your body and often manifests as a single stripe of blisters that wrap around your torso’s right or left side.

Shingles on the chest. https://en.wikipedia.org/wiki/Shingles
Shingles (Herpes zoster) blisters on the neck and shoulder. https://en.wikipedia.org/wiki/Shingles

Varicella-zoster virus causes shingles — the same virus that leads to chickenpox. Once you’ve had chickenpox, the virus lingers in us for the rest of our lives. Years later, the virus may reactivate and result in shingles.

The most common complication is postherpetic neuralgia — A painful condition that causes pain for a long time after the blisters have cleared.

The US Centers for Disease Control (CDC) recommends the shingles vaccine (Shingrix) for adults age 50 and older, whether you have had shingles or not.

Those who have had the Zostavax vaccine (or had a chickenpox vaccine or don’t remember if you had chickenpox) in the past for shingles risk reduction may also consider Shingrix. For those who have had shingles, the CDC offers this guidance:

“If you had shingles in the past, Shingrix can help prevent future occurrences of the disease. There is no specific length of time that you need to wait after having shingles before you can receive Shingrix, but generally you should make sure the shingles rash has gone away before getting vaccinated.”

You should not get Shingrix if you:

  • You have had a severe allergic reaction to any vaccine component or after a dose of Shingrix.
  • Currently have shingles.
  • Are pregnant. Women who are pregnant should wait to get Shingrix.

If you have a minor illness (for example, a cold), you may get Shingrix. But if you have a moderate or severe illness, with or without fever, you should usually wait until you recover before getting the vaccine.

Photo by Diana Polekhina on Unsplash

Shingrix is a non-living vaccine composed of a virus component. Shingrix is given in two doses, with two to six months between the administrations. Protection against shingles with Shingrix may extend beyond five years.

Shingrix side effects

In general, the vaccine is quite safe and provides good protection against shingles. Temporary side effects are not uncommon but may affect your ability to do normal daily activities for two to three days. I made sure to get my vaccine on Friday so that I could have the weekend to recover.

Most individuals report a sore arm (for me, it was moderately severe, tolerable, and associated with swelling at the injection site). Some report generalized fatigue, a headache, fever, shivering, nausea, or stomach pain. Side effects appear to be more common among younger people.

Some who suffer from side effects choose to take over-the-counter pain medicines such as acetaminophen or ibuprofen. Shingrix rarely causes major medical problems, including a serious nervous system disorder known as Guillain-Barré syndrome (GBS).

Please check in with your health care provider if you have ever had an allergic reaction to any component of Shingrix. Those who have had a stem cell transplant, are pregnant (or trying to become pregnant), or have a weakened immune system secondary to a condition or medicine should talk to their health care provider.

Finally, insurance may or may not cover your Shingrix vaccine. Please check your plan.

Effectiveness of Shingrix

The Cleveland Clinic (USA) offers that the shingles vaccine is 97 percent effective in preventing shingles for those ages 50 to 79. It is 91 percent effective in people ages 70 years and older.

Thank you for joining me today for this (non-COVID-19 vaccination roundup). Oh, one more thing:

One More Reason to Get a Flu Shot

Flu vaccination is associated with a 40 percent drop in the risk of getting Alzheimer’s disease.



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Michael Hunter, MD
Michael Hunter, MD
I received an undergraduate degree from Harvard, a medical degree from Yale, and trained in radiation oncology at the University of Pennsylvania. I practice radiation oncology in the Seattle area.

Michael Hunter, MD

I received an undergraduate degree from Harvard, a medical degree from Yale, and trained in radiation oncology at the University of Pennsylvania. I practice radiation oncology in the Seattle area.

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