IFNA1 and infection: While there were some changes in the frequencies of IFN-α synthesizing pDCs in samples from LVL and IVL monkeys, the samples from the HVL monkeys showed a pronounced sustained increase during the acute infection period up to day 56 but it is important to note that there is a marked reduction in IFN-α synthesizing pDCs during late chronic infection (>36 weeks p.i.).