Tag Archives: vaccine

1400 Different Immunization Schedules -What Could Go Wrong?

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A recent study (J Pediatr 2015; 166: 151-6) has examined the frequency of “alternative” (non-standard) vaccination schedules among 222,628 children in New York (2009-2011), using a statewide mandatory immunization information system.

Key findings:

  • 25% of children followed an non-standard immunization schedule.
  • At 9 months of age, children on an non-standard schedule were less likely to be up-to-date (15% compared with 90%, P<0.05).

The authors note that in a separate study that there were “1400 individualized vaccination patterns.”  These patterns break down into three: delays of vaccine, selective refusal of specific vaccines, and reduction in the number of vaccines.

In a brief summary, Sarah Long notes that for parents/doctors –“Although their intent is heightened protection of their children/patients from harm, the result is the opposite.  Alternative “schedules” are completely untested for immunogenicity or safety.”

One limitation of this study is that it was conducted in New York.  There is wide variability in the resistance to vaccination among states.

Bottomline: Their has been an increase in the use of non-standard vaccine schedules.  This is contributing to community vulnerability to vaccine preventable diseases.

A related story: “Disneyland” Measles Outbreak (from USA Today) and from NY Times (1/21/15): Measle cases linked to Disneyland (& unvaccinated students).  1/28/15 Measles in Arizona reaches ‘critical point’

Related blog posts:

More Measles Cases -Here’s the Data

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This past month a recent perspective article (NEJM 2014; 371: 1661-3) provides an update on measles and the problems with vaccination rates.

Key points:

  • More measles cases in 2014 (592 thru Aug 29) than in any year in the past 20.  Already, the number of cases this year is >3-fold the number in 2013 and ~10-fold more than in 2012
  • Most cases are due to infections acquired during travel or due to cases being brought into U.S. by foreign travelers
  • Problem has expanded due to increasing number of unvaccinated children.  Vaccines “that remain in the vial are completely ineffective.”
  • Measles remains one of the most contagious illnesses and typically one person can infect up to 18 susceptible persons.  Due to its contagiousness, a high level of herd immunity (>92-94% immune) is needed to prevent sustained spread of virus.
  • Measles can be deadly with case fatality rate of 0.2% to 0.3% in the developed world and much higher in the developing world (2-15%).
  • Even a few cases are very expensive to control. A 2004 Iowa outbreak of only three patients cost more than $140,000 to contain/investigate.  An outbreak in Arizona with only 7 patients cost more than $800,000.

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Parental Immunity (to Education) and Vaccine Decision-Making

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A recent NY Times editorial by the lead author of a provocative study in Pediatrics (Published online March 3, 2014  (doi: 10.1542/peds.2013-2365) argues that educational efforts to inform parents may not improve vaccination rates in children.

Here’s a link: http://nyti.ms/1sq4X2s  and here’s an excerpt:

“we found that parents with mixed or negative feelings toward vaccines actually became less likely to say they would vaccinate a future child after receiving information debunking the myth that vaccines cause autism.

Surprising as this may seem, our finding is consistent with a great deal of research on how people react to their beliefs being challenged. People frequently resist information that contradicts their views, such as corrective information— for example, by bringing to mind reasons to maintain their belief — and in some cases actually end up believing it more strongly as a result….

A more promising approach would require parents to consult with their health care provider, as the Oregon law also allows them to do. Parents name their children’s doctor as their most trusted source of vaccine information. That trust might allow doctors to do what evidence alone cannot: persuade parents to protect their children as well as yours and mine.

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“Too many vaccines and autism” is debunked

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Based on false science, many parents think that refusing or delaying vaccinations will be safer for their children and decrease the risk of autism.  While the scientific underpinnings for such a concept have no basis (Pediatrics 2004; 114: 793-804, and Institute of Medicine. Immunization safety review: vaccines and autism. Washington, DC: National Academies Press; 2004), lingering concerns persist.  Into this background, another rigorous study (J Pediatr 2013; 163: 561-7) has concluded that there is “no association between exposure to antigens from vaccines during infancy and the development of autism spectrum disorder (ASD),” autism, or ASD with regression.

So how did the authors reach this conclusion?

Using a case-control study from three managed care organizations (MCOs) of 256 children with ASD and 752 control children, the authors examined exposure to total antibody stimulating proteins and polysaccharides from vaccines.  They utilized vaccine registries and medical records.  The children in this study were born between 1994-1999 and were aged 6-13 years at the time of data collection.

The results showed that with each 25-unit increase in total antigen exposure, the adjusted odds ratio (aOR) for ASD was 0.999 for cumulative exposure to age 3 months. The aOR stayed the same at 7 months and 2 years.  When autism or autism with regression were examined, similarly there was no increased risk.

One of the strengths of this study was that members of these MCOs have routine immunizations as a covered benefit; this helps minimize socioeconomic factors which could influence results.  A small number of ASD cases (5%) and controls (2%) had an older sibling with autism; results were unchanged when these children were excluded.

In many ways, this finding is completely anticipated and in agreement with the Institute of Medicines most recent 2013 report on immunizations (The Childhood Immunization Schedule and Safety: Stakeholder …).  As the authors note in their discussion, “beginning at birth, an infant is exposed to hundreds of viruses and other antigens, and it has been estimated that an infant theoretically could respond to thousands of vaccines at once.”

Bottom-line: Vaccines prevent disease without causing autism.  Vaccine refusal increases the risk of disease for those who refuse and creates collateral damage as well.

Related blog entries:

 

Public Health Casualties: Collateral Damage in the War on Terror

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This week there is a fascinating editorial that I almost skipped because the title didn’t grab my attention: “Ensuring Public Health Neutrality” (NEJM 2013; 368: 1073-1075).

This commentary provides background by recollecting Red Cross relief flights to Biafra being shot down by the Nigerian government. “In the minds of some people, ..these attacks were justified by another clear violation of humanitarian neutrality: on at least one occasion, a plane painted with the Red Cross insignia was actually carrying weapons.”

Fast-forward to January 6, 2013.  12 deans of U.S. schools of public health sent a letter to President Obama protesting the conduct of a sham vaccination campaign as part of the hunt for Osama bin Laden.  Apparently, the CIA hired a Pakistani surgeon to go house to house vaccinating children but also drawing back a little blood in the syringe in order to analyze the DNA.  This ploy was not effective in the bin Laden compound as the surgeon’s team was kicked out.

So what are the consequences?

  • Pakistan has expelled foreign staff of the international aid agency Save the Children (Sept 2012)
  • Eight polio vaccination workers were killed (Dec 2012)
  • U.N. has suspended its polio-eradication efforts in Pakistan.  Pakistan is one of three countries where polio has not been eradicated (Nigeria and Afghanistan are the other two).
  • This undermines vaccination in Pakistan where 150,000 children die of vaccine-preventable illness each year.

Using physicians in this manner violates the Hippocratic Oath: “Whatever house I may visit, I will come for the benefit of the sick, remaining free of all intentional injustice.”

The authors note that “although some U.S. policymakers consider immediate national security concerns a higher priority than long-term global health efforts, the CIA’s false vaccination campaign in Pakistan may cause collateral damage with profound long-term implications for national security.  If every aid worker..is suspected of being a spy, the children..of the world will no longer have protection against our greatest killers.”

Public health neutrality –a different twist to think about while you are watching “Zero Dark Thirty.”

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Why Pertusis is resurgent –it’s not what you think

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What are the reasons why pertusis, a vaccine-preventable disease, is epidemic?

According to an editorial by James Cherry (NEJM 2012; 367: 785-87), there are four main reasons.

  • 1) Increased awareness
  • 2) Easier detection with PCR assays
  • 3) Increased use of less potent vaccines, mainly DTaP
  • 4) Possible genetic changes in B pertusis

Useful epidemiology information:

  • 13-20% of adolescents and adults with prolonged cough have B pertusis.
  • Lowest incidence was reported in 1973: 1 per 100,000.
  • In prevaccine era, B pertusis had pattern of epidemics every 2 to 5 years, with peak incidence of 157 per 100,000.
  • In 2010, incidence was 9 per 100,000
  • Neither infection or immunization provides lifelong immunity

His recommendations/conclusions:

  • We need to use the vaccines we have.  This is necessary to avoid the ‘frightening rates of complications and death’ associated with pertusis in infants.
  • Consider starting immunization at an earlier age –1st three doses could be completed by 3 months of age
  • Improved vaccines are needed

Related blog entries:

Protecting the most vulnerable

Hepatitis A vaccine immunity –will it last?

How to stop HBV vertical transmission

HAV vaccination: how long will it take?

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Despite the availability of a safe and effective vaccine, immunization rates in the U.S. remain poor (Pediatrics 2012; 129: 213-221).

In this study which included data from the 2009 National Immunization Survey-Teen, hepatitis A virus (HAV) vaccination  coverage was examined in adolescents 13-17 years of age.  The national coverage for at least 1 dose was 42%; 70% of these vaccinees completed the 2-dose series.  For Georgia, the rates were similar to national data: the 1-dose receipt % was 42.5% and the 2-dose receipt % was 26.3%; 62% completion of 2 doses.

More specific breakdown of coverage rates:

  • 74.3% from 11 states that recommended universal HAV vaccination since 1999
  • 54% from 6 states that recommended consideration of HAV vaccination since 1999 & universal coverage since 2006
  • 27.8% for 33 states that recommended universal vaccination since 2006

While acute HAV rates have been declining, in 2009 there were 1987 reported cases; the CDC estimates that the total number of cases was 21,000 (due to underreporting and asymptomatic cases).  The highest rates of disease were in young adults between 20-29 years of age.

This data is disappointing. Yet, extrapolation from this data indicates that national coverage in seven years, when all states will have had 10 years to implement universal vaccination to young children, could be markedly better.

Additional references:

  • -NEJM 2007; 357: 1685. HAV vaccine effective in preventing cases of HAV after exposure (as good as IVIG). Low rates of HAV c postexposure prophylaxis c HAV vaccine (4.4%) or immune globulin (3.3%). n=1090.
  • -MMWR 2007; 56: 1080-84. Updated recs for IVIG -use only for exposures in infants <12months, immunocompromised persons, persons with chronic liver disease, or persons w contraindications to HAV vaccine.
  • -Pediatrics 2007; 120: 189. Recs from AAP. Recs for vaccine — all children at 1 year of age in US w 2-dose regimen; w/in 1 mo of 1st dose 97% of children & 95% of adults develop protective antibody. VAERS (adverse rxns) 800-822-7967 for forms.
  • -Pediatrics 2007; 119; e12, e22. HAV vaccine is cost-effective.
  • -MMWR 2007; 56: No. SS-3. drop in new infections by 80% compared to previous nadir; HAV 1.5/100,000 & HBV 1.8/100,000
  • -Hepatology 2006; 44: 1589. Decreasing incidence of fulminant HAV ; between 1988-2005, decrease of HAV in UNOS database from 0.7% to 0.1%. Risk factors for severe disease: creatinine >2, ALT <2600, intubation, pressors.
  • -J Pediatr 2004; 144: 327. Maternal antibody decrease HAV vaccine response when administered at 2, 4 & 6 months.
  • -Am J Gastroent 2002; 97: 721-8. ? cost-effective to vaccinate HCV pts; however, ~35% FHF risk if secondarily infected.

More on perinatal HBV

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In addition to a recent blog entry (How to stop HBV vertical transmission), several other recent articles add information about HBV vertical transmission:

  • Gastroenterology 2012; 142: 773-81.  Data from 2386 Taiwanese children born to HBsAg-positive mothers were examined.  HBeAg-positivity increased the likelihood of having an HBV-infected infant (9.26%) despite appropriate immunization & HBIG.  Since HBeAg-posiitivity is associated with higher HBV DNA levels, this is logical based on previous studies. Fulminant HBV developed in 1 of 1050 children who did not receive HBIG; in this study, the majority of mothers with HBeAg-negative HBV did not receive HBIG.
  • Pediatrics 2012; 129: 609-16.  This study examined HBV prevention in the U.S. from 1994-2008.  The CDC created the US Perinatal Hepatitis B Prevention Program (PHBPP) to accelerate progress at eliminating perinatal HBV transmission.  While the number of infants born to HBsAg-positive women with HBV increased from 19,208 to 25,600, the incidence of infants with chronic hepatitis B virus infection among tested infants decreased from 2.1% in 1999 to 0.8% in 2008.  This is due to the fact that 94.4% of PHBPP-managed infants received HBV vaccine and HBIG within 1 day of birth.  Yet, gaps remain.  The number of infants who completed the vaccine series by 12 months actually declined from 86% (1994) to 77.7% (2008). And, in 2008 only one-quarter of CDC’s 25,6000 infants born to HBsAg-positive women had known serologic outcomes.

Related previous post: Looking for trouble