039 - Antipneumococcic Immunity Reactions in Individuals of Different Ages

A bit different today, not exactly about vaccines, but related: this study is concerned with immunity to pneumococcus and how that may change with a person’s age.¹

Sutliff and Finland, the study’s authors, tested the immunity of 134 subjects between the ages of 0 and 83 (some had just been born). They did a number of tests to determine immune responses to three types of pneumococcus (I, II, and III) or against pneumococcus as a whole species. These tests included analyzing the ability of blood to kill the bacteria or to protect mice against infection, and skin reaction tests when inoculated with type-specific polysaccharides or species-specific proteins or other cell contents.

Subjects were tested in hospitals, though for conditions unrelated to respiratory infection. Infants up to 2 were mostly not sick at all, just there for feeding. From 2-6 years, subjects were usually recovering from diphtheria or scarlet fever.

Sutliff and Finland found that, consistently through all type-specific tests, infants up to a couple weeks old had antibodies against all three types of pneumococcus (though most against type II and least against type I), but this immunity disappeared by 3-5 weeks after birth. Interestingly, whether a given infant had antibodies or not correlated very well with the immune status of their mother—if the mother had antibodies, chances are the infant did too, for a couple weeks.

Beyond 3-5 weeks, the proportion of subjects with antibodies gradually grew, so that by 2-11 years it was back up to the same level as among newborns. It did fall somewhat with advanced age though.

The species-specific tests didn’t seem to have any interesting pattern; they just increased as age increased.

So it seems that mothers can transfer their immunity to their offspring, at least to some extent for a short time after birth! Possibly through the placenta, if no other way. But this immunity fades, leaving infants susceptible—and indeed, the groups most susceptible to pneumonia were infants and the elderly.

It wasn’t really clear why immunity increased with age, since the subjects had never had pneumonia; possibly the subjects were exposed to some extent but not enough to become sick, or possibly they were asymptomatic carriers of pneumococcus. It was inconclusive.

Later studies citing this one had some interesting comments. Many interpreted Sutliff and Finland’s results as evidence that infants and young children don’t produce antibodies in response to pneumococcal exposure, which has obvious implications for vaccination efforts.^2–5 (Several other studies support this conclusion.)

Other comments:

 "Although earlier investigators had suggested that pneumococcal antibody declines with advancing years [039, this study], our studies showed an equal prevalence of IgG to PPS in our middle and elderly groups, probably reflecting the dynamic interaction of continued reexposure to S. pneumoniae and cumulative life experience, on the one hand, and antibody attrition together with a possible decline in antibody-forming capacity with aging, on the other."⁶

 "Invasive diseases caused by encapsulated bacteria including...pneumococci occur with highest frequency in infants and children after the decline of maternally derived antibodies."⁷

 "Sutliff & Finland state that immune bodies to the pneumococcus are present in the blood of infants immediately after birth and disappear about the end of the first month. These early type-specific antibodies are similar to those of the mothers, and are probably acquired by placental transmission."⁸

Citations:

1.  Sutliff, W. D. & Finland, M. Antipneumococcic Immunity Reactions in Individuals of Different Ages. J. Exp. Med. 55, 837–852 (1932).

2.  Weintraub, A. Immunology of bacterial polysaccharide antigens. Carbohydr. Res. 338, 2539–2547 (2003).

3.  Lindberg, A. A. Glycoprotein conjugate vaccines. Vaccine 17, Supplement 2, S28–S36 (1999).

4.  Lindberg, A. A. Polyosides (encapsulated bacteria). Comptes Rendus Académie Sci. - Ser. III - Sci. Vie 322, 925–932 (1999).

5.  Prevention of pneumococcal disease in sickle cell anemia. J. Pediatr. 129, 788–789 (1996).

6.  Musher, D. M. et al. Antibody to Capsular Polysaccharides of Streptococcus pneumoniae: Prevalence, Persistence, and Response to Revaccination. Clin. Infect. Dis. 17, 66–73 (1993).

7.  Schneerson, R. et al. Serum antibody responses of juvenile and infant rhesus monkeys injected with Haemophilus influenzae type b and pneumococcus type 6A capsular polysaccharide-protein conjugates. Infect. Immun. 45, 582–591 (1984).

8.  Guthrie, K. J. & Montgomery, G. L. Seven-Year Study of Pneumococcus Type Incidence in the Royal Hospital for Sick Children, Glasgow. J. Hyg. (Lond.) 46, 123–128 (1948).