DISCLAIMER: Staff Discussion Notes (SDNs) showcase policy-related analysis and research being developed by IMF staff members and are published to elicit comments and to encourage debate. The views expressed in SDNs are those of the author(s) and do not necessarily represent the views of the IMF, its Executive Board, or IMF management.

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This Working Paper should not be reported as representing the views of the IMF. The views expressed in this Working Paper are those of the author(s) and do not necessarily represent those of the IMF or IMF policy. Working Papers describe research in progress by the author(s) and are published to elicit comments and to further debate. This paper offers a coherent empirical analysis of the determinants of the real exchange rate, the current account, and the net foreign assets position in low income countries. The paper focuses on indicators specific to low income countries, such as the quality of policies and institutions, the special access to official external financing, and the role of shocks. In addition to more standard factors, we find that domestic financial liberalization is associated with higher current account balances and net foreign asset positions, while capital account liberalization is associated with lower current account balances and net foreign asset positions and with more appreciated real exchange rates. Negative exogenous shocks tend to raise (reduce) the current account in countries with closed (opened) capital accounts. Finally, foreign aid is progressively absorbed over time through net imports, and is associated with a more depreciated real exchange rate in the long-run.

Infection with the protozoan parasite Toxoplasma gondiiis transmitted to humans from infected animals by tissue cysts and oocysts excreted by cats. Immunization with inactivated parasites or recombinant proteins has at best shown partial protection. We constructed a plasmid expressing the SAG1 surface antigen of T. gondii, p1tPASAG1, and showed that animals immunized with the plasmid produce anti-SAG1 antibodies which recognize the native SAG1. Mice immunized with p1tPASAG1 showed 80 to 100% protection against challenge with the non-cyst-producing, virulent RH isolate, compared to an 80% mortality in mice immunized with empty plasmid, which is the greatest efficacy of any vaccine against T. gondii produced so far. The SAG1 molecule was analyzed for potential cytotoxic T-lymphocyte (CTL) epitopes, and four peptides with the best fit were synthesized. The ability of the peptides to stimulate gamma interferon production by CD8+ T cells from p1tPASAG1-immunized mice was tested in an ELISPOT assay, and one new CTL epitope was identified. Adoptive transfer of CD8+ T cells from p1tPASAG1-immunized to naı̈ve mice showed partial protection. In conclusion, DNA vaccination with p1tPASAG1 gave effective protection in mice againstT. gondii infection and the protection could be adoptively transferred by purified CD8+ T cells.