Multivalent and Combination Vaccines in 2026: Promise, Immunologic Questions, and HTA Headaches

Combination and multivalent vaccines have always been the backbone of vaccination programs. An interim high appeared in the mid-1990ies when 6-valent DTaP combination vaccines were developed (DTaP-Hib-IPV-HBV), including as many as 13 antigens depending on the pertussis component. As featured in ViVa 25, there is neither any plausible concern for “too much” nor any evidence in this direction to date. As adult vaccination expands, public health officials increasingly want products that can reduce visits and injections and create clearer value propositions for programs and payers. Combination products can improve timeliness, simplify delivery, and ease pressure on routine schedules. However, evidence also shows that the case for each product still has to be made antigen by antigen, population by population. 1-5 In 2026, the field is no longer asking whether combination vaccines are useful in principle. It is asking a harder set of questions: which combinations are biologically sensible, which combinations are...