0424

Reactogenicity and immunogenicity of a combined measles, mumps, rubella (MMR) and varicella (V) vaccine, compared to concomitant injections of MMR+V in healthy children aged 12-24 months

Zepp F.¹, and Steens J-M.²

¹Johannes Gutenberg Universität, Mainz, Germany; ²GlaxoSmithKline, Rixensart, Belgium

Objective. A tetravalent MMRV vaccine would facilitate the implementation of universal immunization against varicella in early childhood. This study was designed to assess reactogenicity and immunogenicity of a combined tetravalent measles, mumps, rubella and varicella (MMRV) vaccine, compared with MMR+V vaccines administered concomitantly.

Methods. 556 healthy children (12-24 months) were randomised into two groups (ratio 2:1) to receive subcutaneously a single dose of either MMRV, or MMR (PriorixÔ) + V (VarilrixÔ) GSK’s vaccines. Local symptoms were recorded for 4 days after vaccination. General adverse events (fever, rash, parotid and/or salivary gland swelling, signs of meningism, febrile convulsions) were noted for 42 days. Serum samples were taken before vaccination and 42 days after. Anti-MMR antibodies were measured by ELISA (cut-offs: measles, 150 IU/ml; mumps, 4 IU/ml; rubella, 231 IU/ml). Varicella antibodies titers were determined using immunofluorescence assay (cut-off: 1:4).

Results. Incidence of solicited local reactions for MMRV and MMR+V were respectively: 24.8% and 26.9% for redness, 7.1% and 6.6% for swelling, 9.5% and 9.9% for pain. One case of parotid gland swelling was recorded in each group. Generalised rash was observed in 19.9% (MMRV) and 14.8% (MMR+V) of subjects, with decreasing frequencies from the third week after vaccination. Cumulative incidences of rectal temperatures >38.0°C, >39.5°C, and >40°C were 60.5% and 54.9%, 18.3% and 13.7%, and 5.2% and 6.6% for MMRV and MMR+V groups respectively. Four SAEs were recorded (3 for MMRV group and 1 for MMR+V group) and defined as coincidentally associated with vaccination. Post-vaccination immunological data are summarized below (% seroconverted subjects and GMTs):

Group	Measles		Mumps		Rubella		Varicella
	%	GMT	%	GMT	%	GMT	%	GMT
MMRV	98.7	3807	95.7	1968	96.7	43	98.0	188
MMR+V	99.3	2548	97.2	1674	100	51	100	299

Conclusions. Immunogenic responses and local reactions to MMRV and MMR+V vaccines were similar. Considering the advantages of a single over two injections the increase in fever (>39,5°C) observed with MMRV was rated as clinically acceptable.