Resurgence of Vaccine Preventable Illnesses Thomas Dobbs, MD, MPH State Health Officer Mississippi State Department of Health

We are fortunate… The CDC estimates that vaccinations will prevent more than 21 million hospitalizations and 732,000 deaths among children born in the last 20 years.

Immunity and Immunization Exposed to a pathogen (virus, bacteria etc…) Become ill (maybe die) If survive – immune system banks information on the germ to fight it in the future (and prevent illness)

Immunity and Immunization Exposed to a protein (small piece of the germ) or a weakened strain Immune system recognizes as enemy and develops defenses No clinical illness Future protection from that germ

We are spoiled…

Pertussis in Japan In 1974 80% of Japanese children vaccinated against pertussis (whooping cough). 393 cases of pertussis were reported in the entire country, and there were no deaths from pertussis. Rumors began to spread that pertussis vaccination was no longer needed and that the vaccine was not safe, and by 1976 only 10% of children immunized. In 1979 Japan suffered a major pertussis epidemic, with more than 13,000 cases of whooping cough and 41 deaths.

Measles Highly contagious febrile, rash illness 30% of cases with complications Pneumonia and meningitis most common causes of death from measles Subacute Sclerosis Pan- Encephalitis

Why is measles an issue now? We have a highly effective and safe vaccine In the 1980’s – campaign for worldwide measles eradication

Vaccine Study of 12 Children GI Disorder Autism

Wakefield Article 1998 Lancet article linking MMR to Autism Investigations of article: manipulation/fabrication of data Trial lawyers in England paid Wakefield £400,000 ~1996 to find a link between vaccines and autism Wakefield had filed patent for his own autism safe measles vaccine Other authors retracted article Lancet retracted article Wakefield medical license revoked

Do Vaccines Cause Autism? No

How Contagious is Measles?

What is Population Immunity? And why is it important?

Herd Immunity Sustained transmission Transmitting case Susceptible Case (A) Immune (B) Transmission terminated Susceptible (C) (Indirectly Protected) The mass vaccination campaigns allowed health authorities to achieve “herd immunity”. The theory behind the development of “herd immunity” is: in diseases that can be passed from person to person, it is more difficult to pass that disease easily when there are those who are immune to it. The more immune individuals there are, the less likely it is that a susceptible person will come into contact with someone who has the disease For example, if “Person A” had smallpox and exposed “Person B” who was immune because of vaccination, “Person B” would not get ill and could not pass on the disease to “Person C.” when he comes into contact with him. So even if “Person C” is not vaccinated, he gets indirectly protection from the disease.

0 % Immunity 90 % Immunity 95 % Immunity 1 1 1 18 2 1 4 324 8 Measles Transmission and Population Immunity 5832

Herd Immunity Thresholds for Selected Vaccine-Preventable Diseases Immunization Levels Disease Ro Herd Immunity 1999 19-35 Months 1997-1998 Pre-School Diphtheria 6-7 85%* 83%* 9% Measles 12-18 83-94% 92% 96% Mumps 4-7 75-86% 97% Pertussis 12-17 92-94% Polio 5-7 80-86% 90% Rubella 83-85% Smallpox 80-85% __ This slide shows the estimated herd-immunity thresholds needed to stop transmission for several communicable diseases. The Ro , or the number of usual secondary transmissions from a single case of the disease, for several vaccine preventable diseases Notice that smallpox is actually less “transmissible” than measles and pertussis What this slide doesn’t show is the fact that even if desired herd immunity levels can be reached, outbreaks of the disease can and still do occur, though not to the extent they occurred before larger-scale immunity was achieved Because outbreaks of disease can still occur even when a high level of herd immunity is achieved, other measures were ultimately also needed to accomplish the eradication of smallpox *4 doses † Modified from Epid Rev 1993;15: 265-302, Am J Prev Med 2001; 20 (4S): 88-153, MMWR 2000; 49 (SS-9); 27-38

Population immunity and Flu vaccine (50% reduced infectiousness) Ro – 1.5 Cycle 0% Immune 50% immune 100% 1 1000 2 1500 1125 750 3 2250 1265 563 4 3375 1423 422 5 5062 1602 316 6 7594 1802 237 7 11390 2027 178 8 17085 2280 133

It’s a small world after all

Vaccine Preventable Illnesses of the Future… Cervical and Head/Neck Cancer Ebola HIV? Tuberculosis?

Oropharyngeal Cancer in MS From 2012 – 2016 2254 cases of cancer of oropharynx AA – 10.53 / 100,000 Caucasian – 14.01 / 100,000

Cervical Cancer in Mississippi From 2011-2015, 738 new cases of Cervical Cancer were reported, and 292 women died of cervical cancer in Mississippi. For every 100,000 women in MS, 9 new cases of cervical cancer were reported. Mortality 2x higher in African American women

Squamous Cell Cancer 70% of head/neck squamous cell cancer is attributable to HPV virus! ~100% of cervical cancer We have an effective anticancer vaccine – ONLY 52% of girls and 39% of boys complete vaccine series

HPV Coverage in Mississippi