Category: Vaccines

Cancer Vaccines Can Prevent and Treat Many Cancers

The CDC recommends HPV vaccination for 11 and 12 year olds.
The CDC recommends HPV vaccination for 11 and 12 year olds.

When you think about a cancer vaccine, what do you imagine?

Hopefully it isn’t the anti-vaccine myth that the polio vaccine causes cancer – it doesn’t.

Is it a vaccine that prevents all cancer, a so-called universal cancer vaccine? Or vaccines that target specific types of cancer?

Or do you get thoughts of a cancer vaccine that targets and kills cancer cells, treating patients once they already have cancer?

Sound too futuristic?

While a universal cancer vaccine is likely for than a few years away, many people are surprised that some of the vaccines in the current childhood and adolescent immunization schedule can actually prevent cancer.

Another vaccine is approved to treat cancer.

And that’s good news, as cancer is now the leading cause of death in the United States.

Current Cancer Vaccines

When cancer is caused by an infection, it makes sense that you can prevent the cancer by preventing the infection in the first place. That is the rationale for the current preventive cancer vaccines for the human papillomavirus (HPV) and hepatitis B:

  • Gardasil – an HPV vaccine that can be given to preteen boys and girls to protect against most genital warts and anal cancer. Gardasil also protects women against most cervical cancers.
  • Hepatitis B – the hepatitis B vaccine prevents hepatitis B infections, which when they become chronic, can develop into liver cancer.

For these vaccines to be effective, they have to be given before you are exposed to the virus. That is why it is critical for preteens to get the HPV vaccine before they become sexually active teens and young adults.

Since babies can get hepatitis B if their mother is infected and they are more likely to develop chronic hepatitis B infections, it is also important that all infants be vaccinated with the hepatitis B vaccine. Vaccination programs that instead try to target just those newborns of mothers already known to be infected with hepatitis B are much less successful than universal vaccination programs.

In addition to a preventive cancer vaccine, another type of cancer vaccine is the therapeutic or cancer treatment vaccine. This type of cancer vaccine actually helps your body fight the cancer.

So far, only one cancer treatment vaccine has been approved by the FDA.

Provenge is approved for some men with metastatic prostate cancer, increasing their survival by about 4 months. Provenge works by stimulating T lymphocytes, a part of our immune system, to kill prostate cancer cells.

Cancer Vaccines in Development

Although there are just four approved cancer vaccines in use today, there are many more in development, including:

  • DCVax(R)-L – in phase III trials to treat certain patients with glioblastoma multiforme, a type of brain tumor.
  • NeuVax – in multiple phase II trails, including one for certain patients with breast cancer to help prevent breast cancer recurrence.
  • Rindopepimut – in phase III trial to treat certain patients with glioblastoma.
  • Tecemotide – in phase III clinical trials for certain patients with non-small cell lung cancer.

Even more cancer vaccines are in phase I and phase II trials, such as WDVAX, which is in phase I clinical trials to treat certain patients with melanoma.

Although perhaps not as far along and still in early exploratory or pre-clinical research stages, there are other preventive cancer vaccines being developed too. These new vaccines would provide protection against hepatitis C (liver cancer), Epstein-Barr virus (Burkitt lymphoma, non-Hodgkin lymphoma, and Hodgkin lymphoma, etc.), Helicobacter pylori (stomach cancer), schistosomes (bladder cancer), and liver flukes (liver cancer).

What To Know About Cancer Vaccines

In addition to the hepatitis B and HPV vaccines that can prevent cancer, multiple vaccines are being developed to actually treat cancer.

For More Information On Cancer Vaccines

 

Discontinued Vaccines

tripedia
The Tripedia DTaP vaccine was discontinued in 2013.

Most people know that the RotaShield rotavirus vaccine was discontinued in 1999 because it was found to be linked to intussusception.

It took eight years for a new rotavirus vaccine to be licensed.

Lymerix, a Lyme disease vaccine was discontinued in 2002. Unfortunately, we still don’t have a new replacement Lyme disease vaccine.

Vaccines That Have Been Discontinued

More commonly, a vaccine gets discontinued with little notice, as there are other options to keep kids vaccinated and protected.

Other vaccines that are no longer made, include:

  • Cervarix – an HPV vaccine that was discontinued in the US in 2016
  • Comvax –  a Hib/Hepatitis B combination – discontinued in 2014
  • Tetanus toxoid – discontinued 2013
  • Tripedia – a DTaP vaccine – discontinued 2011
  • TriHIBit – a DTaP/Hib combination
  • JE-VAX – discontinued 2005
  • Attenuvax – measles vaccine
  • Mumpsvax – mumps vaccine
  • Meruvax II – rubella vaccine
  • M-R-Vax – measles and rubella combo
  • M-M-Vax – measles and mumps combo
  • Biavax II – rubella and mumps combo
  • Heptavax-B – the original hepatitis B vaccine
  • HIB-Vax – the original Hib vaccine
  • Plague vaccine
  • Poliovax
  • Dryvax – smallpox vaccine
  • Measles-Smallpox combination vaccine
  • Diptussis – a diphtheria/pertussis combination (1949-55)
  • Quadrigen – a DTP/Polio combination (1959-68)
  • Streptococcus vaccine (1952-88)
  • Serobacterin – a pertussis vaccine (1945-54)
  • Rocky mountain spotted fever vaccine (1942-78)
  • Typhus vaccine (1941-79)
  • smallpox vaccine (1917-1976)

Most of these vaccines were discontinued because they simply became obsolete.

Orig. Title: SPvac806.8a
A smallpox vaccination kit included the diluent, a vial of Dryvax smallpox vaccine, and a bifurcated needle.

The Hib-Vax and Heptavax-B vaccines, for example, both use older technology, so these vaccines were discontinued when newer Hib and hepatitis B vaccines were introduced.

And some vaccines are discontinued  or are phased out when they get an update:

  • MMR -> MMR-II (1978)
  • Prevnar 7 -> Prevnar 13 (2010)
  • Gardasil -> Gardasil 9 (2014)

Still other vaccines, like Tripedia and TriHIBit, seemed to get discontinued as a business decision. Through mergers, Sanofi Pasteur, Ltd. ended up with two DTaP vaccines. They had their own Daptacel, but also had Tripedia, a vaccine they acquired from Pasteur Merieux. They ended up discontinuing Tripedia.

Merck also stopped making Comvax not because of “any  product safety or manufacturing issues,” but rather “as part of its ongoing effort to focus company resources on opportunities that provide the greatest value for customers, patients, and public health…”

Cervarix was discontinued because of low market demand. The competing HPV vaccine, Gardasil, had the much larger market share.

Vaccine Manufacturers and Discontinued Vaccines

And of course, some vaccine manufacturers simply stopped making vaccines.

The Texas Department of Health Resources once had a license to make vaccines, including DTP, diphtheria, DT, pertussis, tetanus, Td, and typhoid vaccines since 1950. They completely exited the vaccine market in 1979.

In the 1970s and 80s, dozens of vaccines were discontinued as Miles Inc., Eli Lilly, Parke Davis, and other companies stopped making vaccines.

While that is often downplayed these days, it is important to realize that we used to have much more competition among vaccine manufacturers. For example, in the early 1970s, the DTP vaccine was made by at least 11 different companies! We now have just two that make DTaP. And in many other cases, like for Prevnar, MMR-II, polio, and the chicken pox vaccine, there is just one manufacturer.

For More Information on Discontinued Vaccines:

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Rabies Vaccines

Rabies is a little different than most vaccine-preventable disease.

While we do have a rabies vaccine, in fact, one of the first vaccines when it was developed in 1885 by Louis Pasteur, it is typically given after you have been exposed to the rabies virus. Most other vaccines are routinely given before you are ever exposed to the diseases they prevent.

And the rabies vaccine has changed a lot since Pasteur’s day.

Instead of getting daily shots for 14-21 days, the rabies vaccine is now given when you are exposed, with human rabies immune globulin (HRIG), with further doses of vaccine on days 3, 7, and 14.

Do you need a rabies vaccine after getting bit by an animal?

It depends on the animal and whether or not the animal can be quarantined (confined and observed for rabies symptoms for 10 days).

And while any mammal can get rabies, the ones that are most worrisome are:

  • raccoons, skunks, bats, foxes, and coyotes
  • cats, dogs, and ferrets
  • livestock, cattle, horses

Most importantly, note that “Recent data suggest that transmission of rabies virus can occur from minor, seemingly unimportant, or unrecognized bites from bats.”

The CDC states that “Small rodents like squirrels, hamsters, guinea pigs, gerbils, chipmunks, rats, and mice) and lagomorphs including rabbits and hares are almost never found to be infected with rabies and have not been known to transmit rabies to humans.”

For Information on Rabies Vaccines:

Available Vaccines

In the United States, children routinely get 13 vaccines that protect them against 16 vaccine-preventable diseases including diphtheria, chicken pox, hepatitis A, hepatitis B, Hib, HPV, influenza, measles, meningococcal disease,  mumps, pertussis, pneumococcal disease, polio,  rotavirus, rubella, and tetanus.

Routine Vaccines

These 13 routine childhood vaccines include:

  1. DTaP vaccines (Daptacel or Infanrix) – 5 doses
  2. chicken pox vaccine (Varivax) – 2 doses
  3. hepatitis A vaccines (Havrix or Vaqta) – 2 doses
  4. hepatitis B vaccine (Engerix-B or Recombivax HB) – 3 doses
  5. Hib vaccine (ActHIB, PedvaxHIB, Hiberix) – 3 to 4 doses
  6. HPV vaccines (Cervarix or Gardasil) – 3 doses
  7. Influenza – a yearly flu shot
  8. MMR II – 2 doses
  9. Meningococcal vaccines (Menactra or Menveo) – 2 doses
  10. Pneumococcal vaccines (Prevnar 13 and Pneumovax 23) – 4 doses/1 dose
  11. Polio vaccine – 4 doses
  12. Rotavirus vaccines (Rotarix or RotaTeq) – 2 to 3 doses
  13. Tdap booster (Adacel, Boostrix) – 1 dose

Another vaccine or meningococcal B disease (Bexsero or  Trumenba), which is given as 2 or 3 doses to older teens, is not exactly routine yet. It has a “permissive” recommendation in that parents are told they can get it if they want their kids to avoid menB infections, but it is not required yet.

MenHibrix is yet another vaccine, a combination between Hib Meningococcal Groups C and Y, but it is only given to high risk kids.

Combination Vaccines

The availability of combination vaccines also means that your child doesn’t necessarily need to get as many shots as you see doses. For example, Pediarix combines the three vaccines, DTaP-IPV-HepB, into a single shot. Given three times, when your infant is two, four, and six months, that means that instead of nine shots, your child only gets three.

Other combination vaccines include:

  • Pentacel – DTaP-IPV-Hib
  • Kinrix – DTaP-IPV
  • Quadracel – DTaP-IPV
  • ProQuad – MMR-Varivax

Using combination vaccines, your fully vaccinated and protected child might only get 18 shots by the time he starts kindergarten, not counting yearly flu shots.

Other Vaccines

In addition to the 13 routine vaccines that children get, other vaccines that might be given in special situations include the:

That there are so many vaccines that are not routinely given to kids should dispel the myth that pediatricians are simply vaccine pushers. After all, why don’t they push these vaccines then?

For More Information On Vaccines:

Updated April 26, 2017

Flu Vaccine Recommendations

While you likely get your kids a flu vaccine, it is just as likely that you didn’t get a flu vaccine as a child.

It’s not that flu vaccines are new, it’s just that the recommendations to vaccinate all or most people is relatively new. In the ‘old days,’ flu shots were mainly given to “groups who are at increased risk for influenza-related complications.” Of course, this included many children, such as:

  • children who have chronic disorders of the pulmonary or cardiovascular systems, including asthma
  • children who have required regular medical follow-up or hospitalization during the preceding year because of chronic metabolic diseases (including diabetes mellitus)

That changed in 2001, when a new recommendation was made for the 2002-03 flu season (also when some thimerosal free flu vaccine became available):

Because young, otherwise healthy children are at increased risk for influenza-related hospitalization, influenza vaccination of healthy children aged 6-23 months is encouraged when feasible.

A few years later, vaccinating all healthy children aged 6-23 months became a formal recommendation – for the 2004-05 flu season.

It was expanded to include healthy children between 24 and 59 months before the 2006-07 flu season and again to include healthy children between 5 and 18 years before the 2008-09 flu season.

We got the current universal flu vaccine recommendation, all people who are at least 6 months old who don’t have any contraindications, before the 2010-11 flu season.

Flu Shot Recommendations in Pregnancy

Flu vaccine recommendations during pregnancy have changed over time too.

Since the 2004 flu season, it has been recommended that “women who will be pregnant during the influenza season” get vaccinated, “in any trimester.”

Before that, the recommendation for pregnant women was that:

  • 1983-84 flu season – Physicians should evaluate a pregnant woman’s need for influenza vaccination on the same basis used for other persons; i.e., vaccination should be advised for a pregnant woman who has any underlying high-risk condition.
  • 1990-91 flu season – …pregnant women who have other medical conditions that increase their risks for complications from influenza should be vaccinated, as the vaccine is considered safe for pregnant women. Administering the vaccine after the first trimester is a reasonable precaution to minimize any concern over the theoretical risk of teratogenicity. However, it is undesirable to delay vaccination of pregnant women who have high-risk conditions and who will still be in the first trimester of pregnancy when the influenza season begins.
  • 1994-95 flu season – …pregnant women who have other medical conditions that increase their risks for complications from influenza should be vaccinated because the vaccine is considered safe for pregnant women — regardless of the stage of pregnancy. Thus, it is undesirable to delay vaccination of pregnant women who have high-risk conditions and who will still be in the first trimester of pregnancy when the influenza season begins.
  • 1995-96 flu season – …additional case reports and limited studies suggest that women in the third trimester of pregnancy and early puerperium, including those women without underlying risk factors, might be at increased risk for serious complications from influenza. Health-care workers who provide care for pregnant women should consider administering influenza vaccine to all women who would be in the third trimester of pregnancy or early puerperium during the influenza season. Pregnant women who have medical conditions that increase their risk for complications from influenza should be vaccinated before the influenza season, regardless of the stage of pregnancy. Administration of influenza vaccine is considered safe at any stage of pregnancy.

And finally, for the 1997-98 flu season, the flu vaccine recommendation was updated to “Women who will be in the second or third trimester of pregnancy during the influenza season.”

For More Information on Flu Vaccine Recommendations:

 

Flu Vaccine Recommendation References:
MMWR. Influenza Vaccination Coverage Among Pregnant Women — United States, 2014–15 Influenza Season. September 18, 2015 / 64(36);1000-1005.
MMWR. Prevention and Control of Influenza: Recommendations of the Advisory Committee on Immunization Practices (ACIP) April 25, 1997 / 46(RR-9);1-25.
MMWR. Recommendation of the Immunization Practices Advisory Committee (ACIP) Influenza Vaccines, 1983-1984. July 08, 1983 / 32(26);333-7.

 

Efficacy vs Effectiveness of Vaccines

According to the CDC:

Vaccine efficacy and vaccine effectiveness measure the proportionate reduction in cases among vaccinated persons.

But what’s the difference between vaccine efficacy and effectiveness?

Vaccine efficacy is used when a study is carried out under ideal conditions, for example, during a clinical trial.

Vaccine effectiveness is used when a study is carried out under typical field (that is, less than perfectly controlled) conditions.

Postlicensure studies can often help figure out vaccine effectiveness. For example, the study “Varicella Vaccine Effectiveness in the US Vaccination Program: A Review,” that appeared in The Journal of Infectious Diseases in 2008 “reviewed the results of postlicensure studies of varicella vaccine effectiveness and compared these results with those of prelicensure efficacy trials.”

That study of the chicken pox vaccine found that “the estimates of effectiveness are lower than the prelicensure efficacy,” although several studies found the vaccine “100% effective in preventing combined moderate and severe varicella.”

For More Information On Efficacy vs Effectiveness of Vaccines:

Effectiveness Rates of Vaccines

We know that vaccines work.

But how well do they work?

Taken together, you have to say that vaccines work very well.

Remember, according to the CDC:

Vaccine efficacy/effectiveness (VE) is measured by calculating the risk of disease among vaccinated and unvaccinated persons and determining the percentage reduction in risk of disease among vaccinated persons relative to unvaccinated persons. The greater the percentage reduction of illness in the vaccinated group, the greater the vaccine efficacy/effectiveness.

They aren’t perfect though and some vaccines do work better than others.

For example, the MMR vaccine provides 99% protection (two doses) against measles, while the seasonal flu vaccine can vary from 10% to 60%, depending  on how well the flu vaccine matches the flu virus strains that are getting people sick that year.

Fortunately, most vaccines have over 90 to 95% effectiveness.

The exceptions, in addition to flu vaccines, are the mumps and pertussis vaccines.

In addition to problems with waning immunity, they have lower rates of effectiveness than most other vaccines:

That’s probably why we are seeing more outbreaks of mumps and pertussis among vaccinated children and young adults, although intentionally unvaccinated children and adults are also contributing to most of those outbreaks.

For More Information On Efficacy Rates of Vaccines: