Tag: passive immunity

What Is a Vaccine?

You know what a vaccine is, right?

The word vaccine comes from the vaccinia virus that was in the original smallpox vaccine.
The word vaccine comes from the vaccinia virus that was in the original smallpox vaccine.

The flu shot you get each year is a vaccine.

Vaccine: A product that stimulates a person’s immune system to produce immunity to a specific disease, protecting the person from that disease. Vaccines are usually administered through needle injections, but can also be administered by mouth or sprayed into the nose.

Immunization: The Basics

The smallpox shot that Edward Jenner developed was a vaccine.

Vaccine Definitions

While that is an easy enough definition to understand, that there are many different types of vaccines does make it a little more complicated.

There are:

  • Live-attenuated vaccines – made from a weakened or attenuated form of a virus or bacteria
  • Inactivated vaccines – made from a killed form of virus or bacteria
  • Subunit, recombinant, polysaccharide, and conjugate vaccines – made from only specific pieces of a virus or bacteria
  • Toxoid vaccines – made to target a toxin that a bacteria makes and not the bacteria itself

And of course all of these types of vaccines work to produce immunity to specific diseases – vaccination.

Immunization: A process by which a person becomes protected against a disease through vaccination. This term is often used interchangeably with vaccination or inoculation.

Immunization: The Basics

What other definitions are important to know when you talk about vaccines?

  • active immunity – immunity that you get from having a disease (natural immunity) or getting a vaccine and making antibodies
  • adjuvant – a substance that helps boost your body’s immune response to a vaccine so that you can use a minimum amount of antigen, reducing side effects
  • antibodies – protective proteins that you make against antigens
  • antigens – specific substances (can be part of a virus or bacteria) that trigger an immune response
  • attenuation – a virus or bacteria that is made less potent, so that it can produce an immune response without causing disease
  • elimination – getting rid of a disease in a specific area
  • endemic – the baseline level of disease in an area
  • eradication – getting rid of a disease everywhere (smallpox)
  • epidemic – an increase in the number of cases of a disease over a large geographic area
  • herd immunity – when enough people in a community are protected and have immunity, so that disease is unlikely to spread
  • immunity – protection against a disease
  • incubation period – how long it takes to develop symptoms after you are exposed to a disease
  • outbreak – an increase in the number of cases of a disease over a small geographic area
  • pandemic – an increase in the number of cases of a disease over several countries or continents
  • passive immunity – temporary immunity that you get after being given antibodies, either via a shot of immunoglobulin or a mother’s antibodies are transferred to her baby through her placenta
  • placebo – classically defined as “a comparator in a vaccine trial that does not include the antigen under study”
  • quarantine – isolating someone so that they don’t get others sick
  • titer – an antibody count that can often be used to predict immunity

Got all of that?

So what about variolation, the process that was used before Jenner developed his smallpox vaccine? Was that also a vaccine?

It did produce immunity to smallpox, which is the basic definition of a vaccine, but still, variolation is typically concerned an immunization technique and not a vaccine.

More on Vaccine Definitions

Is the La Leche League Anti-Vaccine?

Why would anyone think that the La Leche League, an organization who’s mission is to support breastfeeding, might be against vaccines?

“Many parents have questions about the compatibility of vaccines and breastfeeding. Your healthcare provider can address any questions that come up for you.”

la leche league international on Vaccines

They certainly don’t make any strong statements supporting vaccines…

“The LLLI Health Advisory Council suggests families discuss the pros and cons of influenza vaccines with their health care practitioners.”

la leche league international on Influenza

The cons of influenza vaccines?

What are those exactly? That the protection babies get from their mother’s pregnancy flu shot doesn’t last until they go to college?

What’s the greatest evidence that they might not support vaccines? I mean, besides anti-vaccine La Leache League leaders who actively say that they are against vaccines?

Bob Sears is giving two lectures on vaccines at an upcoming La Leche League breastfeeding conference.
What exactly will Bob Sears be talking about during his two lectures on vaccines at this upcoming La Leche League breastfeeding conference?

Bob Sears is giving two lectures on vaccines at an upcoming La Leche League breastfeeding conference.

Will he really discuss the benefits of vaccines for pregnant and post-partum mothers and their families?

“Dr. Bob Sears, a renowned Dana Point pediatrician who has been sought out by parents who wish to opt out of the state’s mandatory vaccine requirements, has been placed on probation for 35 months by the Medical Board of California.”

Dr. Bob Sears, renowned vaccine skeptic, placed on probation for exempting child from all vaccinations

And considering that he nearly lost his medical license over giving an improper vaccine exemption, what can we really expect from his talk on California’s vaccine law?

“Remember that La Leche League is exclusively focused on breastfeeding support and has no stance on vaccinations.”

La Leche League USA

No stance on vaccinations?

Actually, with bringing Dr. Bob to their conference, it seems like they made a very clear stance…

“Nursing also allows your baby to give germs to you so that your immune system can respond and can synthesize antibodies! This means that if your baby has come in contact with something which you have not, (s)he will pass these germs to you at the next nursing; during that feeding, your body will start to manufacture antibodies for that particular germ. By the time the next feeding arrives, your entire immune system will be working to provide immunities for you and your baby. If you are exposed to any bacteria or viruses, your body will be making antibodies against them and these will be in your milk.”

Can Breastfeeding Prevent Illnesses?

And they have also done a good job of making it sound like breastfeeding infants don’t need vaccines.

They do!

While breastfeeding is great, it is not a substitute for getting vaccinated. In fact, antibodies in breast milk will not protect a baby against most vaccine-preventable diseases.

If the La Leche League truly wants to support what’s best for kids, they should move away from pushing non-evidence based therapies, especially craniosacral therapy and referrals to chiropractors for breastfeeding problems, and they should take a stand supporting vaccines.

The La Leche League is on this list of other organizations that speak out against vaccines.
The La Leche League is on this list of other organizations that speak out against vaccines.

Then maybe they wouldn’t appear on any lists from the NVIC.

More on Vaccines and the La Leche League

Do My Kids Need the RSV Vaccine?

While I’m sure that many parents would love to get their kids vaccinated and protected against RSV, unfortunately, we don’t yet have an actual RSV vaccine.

We do have Synagis (palivaizumab) though, a monthly injection that can be given to high risk children during RSV season to help prevent them from getting RSV.

Do My Kids Need Synagis?

Synagis is not a vaccine and doesn’t stimulate your body to make antibodies,  but is instead an injection of RSV antibodies made by recombinant DNA technology. That’s why you need to get an injection each month. The antibodies don’t last much longer.

So why doesn’t everyone get Synagis if RSV can be such a deadly disease?

For one thing, there is the high cost of Synagis injections, but there is also the fact that Synagis is only approved to be given to kids who are at high risk for severe RSV infections.

“Palivizumab prophylaxis has limited effect on RSV hospitalizations on a population basis, no measurable effect on mortality, and a minimal effect on subsequent wheezing.”

AAP on Updated Guidance for Palivizumab Prophylaxis Among Infants and Young Children at Increased Risk of Hospitalization for Respiratory Syncytial Virus Infection

And Synagis doesn’t have as a great an effect on preventing RSV infections as we would like. That’s why we need a real RSV vaccine instead.

When to start Synagis is carefully determined by the start of RSV season.
When to start Synagis is carefully determined by the start of RSV season.

So because it likely doesn’t provide that much help to kids who aren’t at very high risk for severe disease, the latest guidelines recommend that Synagis be given to:

  • pre-term infants born before 29 weeks, 0 days’ gestation and who will be younger than 12 months at the start of the RSV season
  • preterm infants with CLD of prematurity, defined as birth at <32 weeks, 0 days’ gestation and a requirement for >21% oxygen for at least 28 days after birth.
  • certain infants with hemodynamically significant heart disease during their first year of life and might include infants with cyanotic heart defects, infants with acyanotic heart disease who are receiving medication to control congestive heart failure and will require cardiac surgical procedures and infants with moderate to severe pulmonary hypertension, infants with heart lesions that were corrected by surgery, but who continue to require medications for congestive heart failure, and children under age two years who have had a cardiac transplant.
  • certain children in their second year of life if they required at least 28 days of supplemental oxygen after birth and who continue to require medical intervention (supplemental oxygen, chronic corticosteroid, or diuretic therapy)
  • certain infants in their first year of life with pulmonary abnormality or neuromuscular disease that impairs the ability to clear secretions from the upper airways
  • certain children in their second year of life if they will be profoundly immunocompromised during RSV season

Those who qualify get up to five monthly doses, beginning in November, to help make sure they are covered through the peak of RSV season – December to May.

Whether or not your high risk child gets Synagis, you can help to reduce their risk of getting RSV by making sure they are not exposed to tobacco smoke, keep them away from crowds of people, wash hands often, and if possible, keep them out of day care.

And get them all of their other vaccines, including a flu shot once they are six months old.

What do you do if your high risk child was denied Synagis by your insurance plan? If your infant has a qualifying condition, your pediatrician should be able to help you write an appeal to your insurance company stating that getting Synagis is a medical necessity.

More on Synagis and RSV Vaccines

How Does a Mother’s Flu Shot Protect a Newborn Baby?

We know that pregnant women are supposed to get a flu vaccine.

Although recommendations on exactly when to get it have changed over the years, it has been a universal recommendation since at least the 1994-95 flu season.

But why?

How Does a Mother’s Flu Shot Protect a Newborn Baby?

One obvious way that a flu shot provides protection during pregnancy is that it reduces your risk of getting the flu while you are pregnant.

A flu shot during your pregnancy protects both you and your baby.
A flu shot during your pregnancy protects both you and your baby.

That’s good, as having the flu while you are pregnant can lead to preterm labor, a premature birth, birth defects, or a miscarriage. And of course, the flu can be life-threatening for pregnant women.

Getting a flu shot while you are pregnant can also help to make sure that you don’t get the flu after your baby is born, which not only keeps you healthy, but decreases the chance that your baby will be exposed to the flu. After all, if you get the flu, no matter how much you try to cover your cough and wash your hands, there is a good chance that you will give it to your baby.

And since babies can’t get flu shots of their own until they are at least six months old, a flu shot during pregnancy helps to make sure that your baby gets some of antibodies to protect them from the flu.

“When you get a flu shot, your body makes antibodies that also pass to your fetus. This means your baby has protection against the flu after birth. This is important because infants less than 6 months of age are too young to get the flu shot.”

Frequently Asked Questions for Patients Concerning Influenza (Flu) Vaccination During Pregnancy

Do you have to wait until late in your pregnancy to make sure that the most antibodies get passed to your baby?

While that might seem like a good idea, especially since that’s what we do for the Tdap vaccine and protection against pertussis, there are several reasons that we don’t do that with the flu vaccine, including that:

  1. pregnant mothers need the protection before flu season hits, so waiting would not be safe and could mean that you get sick with the flu before getting your shot
  2. protection from the flu vaccine shouldn’t wane or wear off so quickly that you need to get it later, after all, the earliest that you can get vaccinated is when flu vaccines first become available in August or September and that should provide good protection past the peak of flu season

When you get your flu shot while pregnant is going to have more to do with when you got pregnant in relation to the start of flu season more than anything else.

“The flu shot can be safely given during any trimester. Pregnant women can get the flu shot at any point during the flu season (typically October through May). Pregnant women should get the shot as soon as possible when it becomes available. If you are pregnant, talk with your obstetrician–gynecologist (ob-gyn) or other health care provider about getting the flu shot.”

Frequently Asked Questions for Patients Concerning Influenza (Flu) Vaccination During Pregnancy

Most importantly, remember that flu shots are considered an “essential component of prenatal care.”

While everyone should get a flu vaccine each year, since pregnant women are in a high risk group for flu complications, you should especially make sure that you get vaccinated and protected if you are pregnant. Everyone around you should get vaccinated too!

More on Flu Shot Protection During Pregnancy

What to Do If Your Child Is Exposed to Hepatitis A

Hepatitis A is a vaccine preventable disease.

The hepatitis A vaccine was first added to the immunization schedule in 1996, but wasn’t made a universal recommendation for all children until 2006. At first, it was just given to high risk kids.

Now all toddlers begin to get a two dose hepatitis A vaccine series beginning when they are 1 to 2 years old, with 6 to 18 months between the doses.

Unfortunately, unlike many other vaccines, there was never a catch-up plan for those who were unvaccinated, so some teens and many adults are still not vaccinated and still not protected against hepatitis A infections.

Getting Exposed to Hepatitis A

How do you get hepatitis A?

“The hepatitis A virus is able to survive outside the body for months. High temperatures, such as boiling or cooking food or liquids for at least 1 minute at 185°F (85°C), kill the virus, although freezing temperatures do not.”

CDC on Hepatitis A Questions and Answers

Unlike hepatitis B, which is spread through blood and body fluids, people who are infected with hepatitis A shed the virus in their stool.

So you can get infected by having close contact with someone who has hepatitis A or by eating or drinking contaminated food or water.

How do you know if you have been exposed?

While an employee in the produce department at a Kroger in Kentucky recently exposed folks to hepatitis A, back in 2016 it was a Whole Foods in Michigan that was linked to an outbreak.
While an employee in the produce department at a Kroger in Kentucky recently exposed folks to hepatitis A, back in 2016 it was a Whole Foods in Michigan that was linked to an outbreak.

Exposures are most common in local common-source outbreaks caused by sick food handlers at restaurants and grocery stores and multi-state hepatitis A outbreaks caused by contaminated foods. These types of exposures are usually announced by your local or state health department.

Other exposures occur if you are living with someone who develops hepatitis A or travel to a country where hepatitis A is still common.

What to Do If Your Unvaccinated Child Is Exposed to Hepatitis A

If your unvaccinated child is exposed to hepatitis A, you should talk to your pediatrician or local health department about starting post-exposure prophylaxis as soon as possible and not longer than 14 days, including either:

  • the first dose of hepatitis A vaccine, with plans to get the second dose of vaccine in 6 months, or
  • a dose of immune globulin (provides a passive transfer of antibodies)

In general, getting the hepatitis A vaccine is preferred over getting immune globulin for most healthy people between 12 months and 40 years of age. For infants less than 12 months (too young to be vaccinated) and unvaccinated adults over age 40 years, immune globulin is preferred after an exposure to hepatitis A.

Immune globulin is also preferred for anyone who is immunocompromised or chronic liver disease.

What if it has been more than 14 days since the exposure?

While it is likely too late for immune globulin, your unvaccinated child should still likely get a dose of hepatitis A vaccine to protect against future exposures. And watch carefully over the next 15 to 50 days (the incubation period) for symptoms of hepatitis A, which can include jaundice, fever, and vomiting, etc. Many children don’t have symptoms though, so your child could develop hepatitis A, and be contagious and expose others without your even knowing it.

If post-exposure vaccination works, can’t you just wait until your child is exposed to get vaccinated? That might work – if you could be sure about each and every exposure that your child will ever have. Since that’s not possible, don’t delay getting vaccinated and put your child at risk of getting hepatitis A.

What to Do If Your Vaccinated Child Is Exposed to Hepatitis A

The hepatitis A vaccine is very effective.

One dose provide 95% protection against hepatitis A infections and the second dose boosts the efficacy rate up to 99%.

If your child is partially vaccinated, with just one dose and has been exposed to hepatitis A, get the second dose if it has been at least six months since he was vaccinated. Otherwise, talk to your pediatrician or local health department, but your child is likely considered protected.

What to Know About Getting Exposed to Hepatitis A

Learn what to do if your child is exposed to hepatitis A, especially if they aren’t already vaccinated and protected.

More on Getting Exposed to Hepatitis A

Alternatives to Getting Vaccinated

Are there any alternatives to getting vaccinated?

Sure. You can read about them all day long from holistic “experts” and on anti-vaccine websites.

Are there any good alternatives to getting vaccinated?

No. At least not if you want to be truly protected from vaccine-preventable diseases.

Alternatives to Getting Vaccinated

Kids who are born with immune disorders don't have to live in isolation bubbles any more, but they still need protection.
Kids who are born with immune disorders don’t have to live in isolation bubbles any more, but they still need protection. Photo by Baylor College of Medicine

Unfortunately, some folks don’t have other options and they need to look at an alternative for protection from vaccine-preventable diseases that doesn’t include vaccines.

These are the folks with contraindications or true medical exemptions for vaccines.

What do they do?

It depends on the specific circumstances, but in most cases, except for live vaccines or any other specific vaccine that is contraindicated, they usually get vaccinated.

Extremely few people can’t get at least some, if not most, of their vaccines, even if they do have contraindications to some others. And many exemptions are temporary.

“Parents need to balance the need of the immunoreconstituted child (post-transplant SCID) to be protected from exposure to infection from live vaccines and close contact–transmitted vaccine-derived infection with the need of the child to integrate into society and develop social and learning skills in group environments.”

Medical Advisory Committee of the Immune Deficiency Foundation

They also try to avoid people who are sick and  try to make sure that everyone around them is vaccinated to help maintain herd immunity levels of protection.

Neither is always possible though.

Post-Exposure Prophylaxis

Post-exposure prophylaxis is another option that is available to help prevent some vaccine-preventable diseases. For example, if your unvaccinated child is exposed to measles, they can often receive immune globulin to help them avoid getting measles.

Regimens for post-exposure prophylaxis are also available for:

  • chicken pox – varicella zoster immune globulin or immune globulin
  • diphtheria – antibiotics
  • hepatitis A – immune globulin
  • hepatitis B – hepatitis B immune globulin
  • influenza – oseltamivir (Tamiflu) and zanamivir
  • meningococcal disease – antibiotics
  • pertussis – antibiotics
  • rabies – rabies immune globulin
  • tetanus – tetanus immune globulin

When possible, immunization typically accompanies these post-exposure prophylaxis regimens.

There is one big problem with these types of post-exposure prophylaxis regimens though. You are not always going to know when your child is exposed to someone else with a vaccine-preventable disease. While some exposures might be obvious, like if your child steps on a rusty nail or is bitten by an unvaccinated dog who has rabies, you might miss some others.

Bogus Alternatives to Getting Vaccinated

What other alternatives to getting vaccinated are out there?

Unfortunately, there are none that work.

Many bogus alternatives to getting vaccinated are pushed by those opposed to vaccines as ways to boost your immunity, and they can include:

  • breastfeeding – while breastfeeding is great and always encouraged, the passive immunity it provides will not protect your baby from most vaccine-preventable diseases, as it contains IgA antibodies, not the IgG antibodies you would need to prevent diseases like measles, tetanus, chicken pox, and Hib, etc.
  • homeopathic vaccines – nosodes are homeopathic vaccines that have been diluted so much that they are supposed to retain a memory of the original substance. Even if they did – that’s not how immunology works.
  • herbs – neither echinacea, goldenseal root, nor elderberry syrup is going to boost your child’s immunity
  • vitamins – unless your child is severely vitamin deficient, taking vitamins isn’t going to boost their immunity, whether they are taking extra vitamin C or extra vitamin D
  • foods – Japanese mushrooms, kale, broccoli, lettuce, cabbage, avocados, ginger, black currants, graviola, green veggies, onion seeds, and berries might all be great to eat, but they aren’t going to boost your immunity
  • probiotics – they may help prevent antibiotic associated diarrhea, but there is not much evidence that taking them regularly does anything else
  • essential oils – they sometimes smell nice, but they aren’t going to boost your child’s immune system
  • chiropractic adjustments – not going to work
  • sun exposure – in addition to the worries about skin cancer, not only does extra sun exposure not boost your immune system, the WHO reports that “Several studies have demonstrated that exposure to environmental levels of UV radiation alters the activity and distribution of some of the cells responsible for triggering immune responses in humans. Consequently, sun exposure may enhance the risk of infection with viral, bacterial, parasitic or fungal infections, which has been demonstrated in a variety of animal models.”
  • fermented cod liver oil – this is not going to boost your child’s immune system, but folks should also know that there have been reports that the products that people have been buying and using for years were rancid and actually making them sick! There are much better ways to get vitamin D and vitamin A in your diet than taking fermented cod liver oil each day.

What about natural immunity?

While natural immunity can in some ways be more effective than vaccine induced immunity, it often comes at a price. You have to recover from the disease, hopefully without any long term consequences, to develop natural immunity.

What to Know About Alternatives to Getting Vaccinated

People who truly can’t be vaccinated rely on herd immunity, because in most cases, there are no effective alternatives for vaccines.

More On Alternatives to Getting Vaccinated

Myths About Your Baby’s Immature Immune System

Newborns and infants have immature immune systems, at least as compared to older children and adults.

Premature babies can usually get all vaccines on schedule - at their chronological age, not an adjusted age based on being a preemie.
Premature babies can usually get all vaccines on schedule – at their chronological age, not an adjusted age based on being a preemie. Photo by Vincent Iannelli, MD

That doesn’t mean that their immune system is so immature they they can’t fight off many infections or that they shouldn’t be vaccinated. Even premature babies should usually be vaccinated on time.

Your Baby’s Immature Immune System

So just how immature is their immune system?

“A picture emerges of a child born with an immature, innate and adaptive immune system, which matures and acquires memory as he or she grows.”

Simon et al on Evolution of the immune system in humans from infancy to old age

It is immature enough that the protection that they get from passive immunity and transplacental transfer of antibodies before they are born is considered critical to protect them from many infections.

“After birth, the sudden enormous exposure to environmental antigens, many of them derived from intestinal commensal bacteria, calls for a rapid change to make distinct immune responses appropriate for early life.”

Simon et al on Evolution of the immune system in humans from infancy to old age

Fortunately, their immune system quickly matures and develops, so that as their maternal protection begins to fade, they are “better armed with the maturing innate and adaptive immune systems.”

“The risks are now much reduced by vaccinations, which stimulate protective immune responses in the maturing immune system.”

Simon et al on Evolution of the immune system in humans from infancy to old age

Getting fully vaccinated  on time helps too.

Myths About Your Baby’s Immune Response to Vaccines

Getting vaccinated?

With an immature immune system?

How does that work?

It will likely come as a surprise to some folks, but it actually works quite well!

“Although infants can generate all functional T-cells (ie, Th1, Th2, and cytotoxic T-cells), infant B-cell responses are deficient when compared with older children and adults. Infants respond well to antigens (such as proteins) that require T-cell help for development. However, until about 2 years of age, the B-cell response to T-cell-independent antigens (such as polysaccharides) is considerably less than that found in adults.”

Offit et al on Addressing Parents’ Concerns: Do Multiple Vaccines Overwhelm or Weaken the Infant’s Immune System?

In fact, we know that:

  • newborns respond well to the birth dose of the hepatitis B vaccine
  • the birth dose of BCG vaccine is effective at preventing severe TB disease
  • infants respond well to the vaccines in the primary series that they get at 2, 4, and 6 months
  • while infants respond well to most vaccines, to “circumvent the infant’s inability to mount T-cell-independent B-cell responses,” we use some conjugate vaccines when necessary, like Hib and Prevnar. This is especially important because their immature immune system puts them at extra risk for Hib and pneumococcal disease. Why? These are “bacteria that are coated with polysaccharides.”
  • older infants and toddlers respond to other vaccines, including MMR and the chicken pox vaccine, once maternal antibodies began to fade and can no longer cause interference.

So vaccines work in babies and young infants, just like they do for older children, teens, and adults.

But that makes you wonder, if anti-vaccine folks don’t think that vaccines work in these younger children and that their immune system is so immature, then how can these vaccines overstimulate their immune system???

They don’t.

Both the immunogencity and safety of vaccines for infants are well studied.

What to Know About Your Baby’s Immature Immune System

Vaccines work well to help protect newborns and infants as their immune system continues to develop and mature.

More About Your Baby’s Immature Immune System