Measles Immunity

By Emily Alvarez

Measles is a highly contagious infectious disease that made its way into London in the late 19th and 20th centuries. Because of the contagious nature of measles, many were quickly exposed to the virus. This exposure allowed people’s bodies to build up immunity to measles, therefore preventing them from acquiring the disease again. Immunity came in many forms, including through contact with the disease as well as immunity obtained from a sufficient dosage of vaccination.

In the late 19th century and early 20th century, immunity was primarily acquired naturally, meaning after exposure to the live virus the immune system builds up a tolerance to the disease. A person would contract measles and experience the symptoms, but after the first encounter most develop a permanent immunity (MOH Acton 1936). This naturally acquired active immunity that occurs after someone suffers from measles causes one’s body to react by producing anti-toxins that will fight the disease for the rest of their lives (MOH Acton 1932). Before the development of the measles vaccination in 1963, it was reported that to protect children from measles doctors would inject a serum into patients in hopes of giving the patient passive immunity. The serum consisted of the blood of those who had acquired measles, which was injected into the children who had not yet gained immunity from contact with measles or to those who were experiencing symptoms in hopes of lessening the effects of the disease (MOH Harrow 1960). The effectiveness of the serum depends on the time of dosage, because if the serum was not administered at a time when the symptoms were still new, the patient would not obtain immunity (MOH Coulsdon and Parley 1944). The immunity gained from this serum would be passive and only last the patient a few weeks, but it was an effective tool to ward-off an attack from the virus.

Dr. J. Alibert taking serum from a servant’s baby to vaccinate the child

Children were reported on most frequently because of their increased likelihood of acquiring measles. When born, many children acquire passive immunity from their mothers. The child has antibodies that they obtained from their mother that will give them temporary immunity to measles (MOH Camberwell 1951). Breast-fed babies were less likely to contract measles in their early stages of life due to natural immunity that came from their mother’s milk (MOH Acton 1936). Violent cases of measles were often reported in schools, leading to prolonged school closures. The probability of a measles outbreak spreading through a classroom depended on the proportion of the number of children that had gained immunity versus children who had not yet acquired immunity (MOH Acton 1934 ). If more children than not had immunity to measles, it was not as likely for a measles outbreak to affect a classroom or the entire school. It was recommended that if it were decided to close a school due to a measles outbreak, closure should happen after only a few cases have occurred (MOH Hackney 1888). If the school was not closed at the commencement of the outbreak, children who had not acquire natural immunity would then get measles, therefore worsening the outbreak. Often, children that were exposed to measles would lose their immunity within the year, therefore putting them at risk to acquire the disease again, which explains the young mortality age of measles (MOH Acton 1934).

” For every 100 children suffering from a clinical attack of measles in a densely populated area about 300 other become temporarily immunized, and of these 250 lose their immunity again before the next epidemic is due.”

– Report of the Medical Officer of Health for Acton (MOH Action 1934)

It was noted in reports that outbreaks of measles would often occur every other year. This was because after a few years passed, some would lose their immunity and younger children who did not acquire the disease in the previous years now had it, making the pattern of outbreaks every alternate year (MOH Carshalton 1952). The extent of a measles outbreak in an area depended almost solely on the proportion of the population that had acquired natural immunity (MOH Carshalton 1952). One doctor believed that it was not immunity that protected children under 5 from measles, however, it was their lack of exposure to infection because of their young age and most not yet entering school (MOH Kensington 1960 ). This could be linked to the prevalence of measles in children aged five to ten years old because they are more likely to come in contact with measles through their classmates.

Until the development of the measles vaccination in the early 1960s, immunity from measles was built up naturally through contact with the disease or from temporary immunity that was commonly seen in breastfed babies. After the measles vaccination entered London, the number of people who had acquired immunity from the injection increased, which meant there was a reduction in the number of subjects that gained natural immunity through contracting measles (Sutherland, I., and P. M. Fayers). This increase of immunity in Europe due to the vaccination ultimately decreased the number of outbreaks. By the time the measles vaccination was used in London, a large majority of the population had acquired natural immunity through exposure to the measles. The measles vaccination allowed those who had not yet acquired immunity to gain immunity, causing the severity of the coming outbreaks to be less ( MOH Redbridge 1968). It was common for those who received the injection to confer permanent, life-long immunity to measles, which is why following the use of vaccination in Europe, the number of outbreaks along with fatalities decreased (Krugman, Saul, Giles, Friedman, and Stone). It was observed that following the implementation of the measles vaccine, the younger population became increasingly more immune to measles, while children over 10 showed less immunity than the younger population (Fine, Paul EM, and Jacqueline A. Clarkson). This is an interesting parallel, because prior to the vaccine the age group that measles primarily affected was under 10 years of age. The introduction of the measles vaccination altered the course of the disease and allowed millions to gain immunity.

References:

Primary:

  1. MOH Acton 1936
  2. MOH Acton 1932
  3. MOH Harrow 1960
  4. MOH Coulsdon and Parley 1944
  5. MOH Acton 1934
  6. MOH Hackney 1888
  7. MOH Carshalton 1952
  8. MOH Redbridge 1968
  9. MOH Kensington 1960
  10. MOH Camberwell 1951

Secondary:

Fine, Paul EM, and Jacqueline A. Clarkson. “Measles in England and Wales—II: the impact of the measles vaccination programme on the distribution of immunity in the population.” International Journal of Epidemiology 11, no. 1 (1982): 15-25.

Krugman, Saul, Giles, Friedman, and Stone. “Studies on immunity to measles.” The Journal of pediatrics 66, no. 3 (1965): 471-488.

Sutherland, I., and P. M. Fayers. “Effect of Measles Vaccination on Incidence of Measles in the Community.” The British Medical Journal 1, no. 5751 (1971): 698–702. https://doi.org/10.1136/bmj.1.5751.698.