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ABSTRACTOn 13 October 2023, the National Directorate for Livestock Development in Mozambique was notified of a suspected outbreak of avian influenza in commercial layers. Samples were screened by real-time and conventional RT–PCR and were positive for both H7 and N6. Full genome sequences were obtained for three representative samples. Sequence analysis of the H7 cleavage site confirmed that the viruses were highly pathogenic (i.e. 333- PEPPKGPRFRR/GLF-346). In addition, the H7 and N6 sequences were highly similar (from 99.4-99.5% and 99.6-99.7% for the HA gene and the NA gene, respectively) to the sequences of a H7N6 virus identified in the Republic of South Africa in May 2023 indicating a similar origin of the viruses. The identification of H7N6 HPAIV in Mozambique has important implications for disease management and food security in the region.

Introduction: Peste des petits ruminants (PPR) or goat plague is a highly contagious viral disease of small ruminants such as sheep and goats with 90% and 100% morbidity and mortality, respectively. This study was aimed at assessing Peste des petits Ruminants Virus (PPRV) specific antibodies in vaccinated pregnant ewes and subsequently the passive immunity in their lambs. Methods: Seventeen apparently healthy sheep (8 pregnant and 9 non pregnant), 2-3 years old and kept under semi-intensive system of management were used. Ewes were vaccinated with the National Veterinary Research Institute PPR vaccine Nigeria strain 75/1 with a virus titre of 103 Tissue Culture Infectious Dose (TCID). Serum Samples were collected from all the sheep before and after vaccination at interval of two weeks for a period of seven months. The resultant (8) lambs were given birth to, blood sample were collected for four month and sera samples were examined using Competitive ELISA (c-ELISA) for the presence of specific PPR-N antibodies. Results: The analysed result showed that there was significant difference (P < 0.05) in the mean PPRV-N specific antibody c-ELISA values (0-13) before vaccination and the percentage competition protective values (> 50%). However, no significant difference (p > 0.05) post-vaccination in both pregnant and non-pregnant ewes was observed throughout the period of the study with mean PPRV-N specific c-ELISA antibodies of 72-86 and 52-86, respectively. The mean PPRV-N specific antibodies values were maintained within the protective value (> 50 %). The result of this study also showed that there was significant difference (P < 0.05) with mean PPRV-N specific c-ELISA antibodies (17.3-29.4; 87.5%) of lambs born to vaccinated pregnant Yankassa ewes from 8 weeks. Conclusion: This study showed that vaccination does not affect pregnancy with Nigeria 75/1 strain of PPR vaccine in ewes as there was no record of abortion. There was a rapid PPR maternal antibody decay in lambs from the 8th week of age as it was observed that at age 10 weeks, only 37.5 % of the lambs had protective titre. It is therefore recommended that lambs can be vaccinated at 9th week to avoid the window of susceptibility to PPR virus infection.