ihTs oby ahs ienisingmt udaesc by Sptre inmoepaeun, teh tmso ncomom seacu of fnitiecous tginiiensm ni en.laegr hTe aieccvn rfo perSt oeumnp is a repdacilhsyaco pternoi tgjuenoac aeccvi.n eTh treho joram betrcaai wtih a eicnavc ielk htsi si .H iueenflzna.
PCV13 for strep pneumo is polysaccharide conjugated to diptheria toxin-like protein (FA20-105). This is needed for a T-cell dependent response which allows for class switching and production of IgG Ab. This is a much more robust immune response. This provides memory and is why the vaccine is given at an early date.
On the contrary, antigens lacking a protein (such as the capsular polysaccharide) such as PPSV23 vaccine are not presented to T-cells, and therefore have a much weaker response + do not class switch.
submitted by suckitnbme(176), 2020-01-25T21:35:55Z
There are two types of pneumococcal vaccines for Strep pneumoniae.
The pneumococcal conjugate vaccine (PCV13) is given to children under 5. It is also given to adults age >=65 who are immunocompromised (PPSV23 is also given afterwards).
The polysaccharide vaccine PPSV23 is given to adults, the indications for which I won't go into.
Since this patient is 2-years old he should have received the conjugate vaccine per CDC guidelines.