Serological Immunity to Smallpox in New South Wales, Australia
The re-emergence of smallpox is an increasing and legitimate concern due to advances in synthetic biology. Vaccination programs against smallpox using the vaccinia virus vaccine ceased with the eradication of smallpox and, unlike many other countries, Australia did not use mass vaccinations. However...
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| Format: | Article |
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MDPI AG
2020-05-01
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| Series: | Viruses |
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| Online Access: | https://www.mdpi.com/1999-4915/12/5/554 |
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| author | Valentina Costantino Mallory J. Trent John S. Sullivan Mohana P. Kunasekaran Richard Gray Raina MacIntyre |
| author_facet | Valentina Costantino Mallory J. Trent John S. Sullivan Mohana P. Kunasekaran Richard Gray Raina MacIntyre |
| author_sort | Valentina Costantino |
| collection | DOAJ |
| description | The re-emergence of smallpox is an increasing and legitimate concern due to advances in synthetic biology. Vaccination programs against smallpox using the vaccinia virus vaccine ceased with the eradication of smallpox and, unlike many other countries, Australia did not use mass vaccinations. However, vaccinated migrants contribute to population immunity. Testing for vaccinia antibodies is not routinely performed in Australia, and few opportunities exist to estimate the level of residual population immunity against smallpox. Serological data on population immunity in Australia could inform management plans against a smallpox outbreak. Vaccinia antibodies were measured in 2003 in regular plasmapheresis donors at the Australian Red Cross Blood Service from New South Wales (NSW). The data were analysed to estimate the proportion of Australians in NSW with detectable serological immunity to vaccinia. The primary object of this study was to measure neutralising antibody titres against vaccinia virus. Titre levels in donor samples were determined by plaque reduction assay. To estimate current levels of immunity to smallpox infection, the decline in geometric mean titres (GMT) over time was projected using two values for the antibody levels estimated on the basis of different times since vaccination. The results of this study suggest that there is minimal residual immunity to the vaccinia virus in the Australian population. Although humoral immunity is protective against orthopoxvirus infections, cell-mediated immunity and immunological memory likely also play roles, which are not quantified by antibody levels. These data provide an immunological snapshot of the NSW population, which could inform emergency preparedness planning and outbreak control, especially concerning the stockpiling of vaccinia vaccine. |
| first_indexed | 2024-03-10T19:46:53Z |
| format | Article |
| id | doaj.art-9c88241189e0454ab5d10cc5dad9d0f5 |
| institution | Directory Open Access Journal |
| issn | 1999-4915 |
| language | English |
| last_indexed | 2024-03-10T19:46:53Z |
| publishDate | 2020-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Viruses |
| spelling | doaj.art-9c88241189e0454ab5d10cc5dad9d0f52023-11-20T00:47:24ZengMDPI AGViruses1999-49152020-05-0112555410.3390/v12050554Serological Immunity to Smallpox in New South Wales, AustraliaValentina Costantino0Mallory J. Trent1John S. Sullivan2Mohana P. Kunasekaran3Richard Gray4Raina MacIntyre5Biosecurity Program, Kirby Institute, Faculty of Medicine, University of New South Wales, Sydney, NSW 2052, AustraliaBiosecurity Program, Kirby Institute, Faculty of Medicine, University of New South Wales, Sydney, NSW 2052, AustraliaCentral Clinical School, University of Sydney, Sydney, NSW 2052, AustraliaBiosecurity Program, Kirby Institute, Faculty of Medicine, University of New South Wales, Sydney, NSW 2052, AustraliaSurveillance Evaluation and Research Program, Kirby Institute, Faculty of Medicine, University of New South Wales, Sydney, NSW 2052, AustraliaBiosecurity Program, Kirby Institute, Faculty of Medicine, University of New South Wales, Sydney, NSW 2052, AustraliaThe re-emergence of smallpox is an increasing and legitimate concern due to advances in synthetic biology. Vaccination programs against smallpox using the vaccinia virus vaccine ceased with the eradication of smallpox and, unlike many other countries, Australia did not use mass vaccinations. However, vaccinated migrants contribute to population immunity. Testing for vaccinia antibodies is not routinely performed in Australia, and few opportunities exist to estimate the level of residual population immunity against smallpox. Serological data on population immunity in Australia could inform management plans against a smallpox outbreak. Vaccinia antibodies were measured in 2003 in regular plasmapheresis donors at the Australian Red Cross Blood Service from New South Wales (NSW). The data were analysed to estimate the proportion of Australians in NSW with detectable serological immunity to vaccinia. The primary object of this study was to measure neutralising antibody titres against vaccinia virus. Titre levels in donor samples were determined by plaque reduction assay. To estimate current levels of immunity to smallpox infection, the decline in geometric mean titres (GMT) over time was projected using two values for the antibody levels estimated on the basis of different times since vaccination. The results of this study suggest that there is minimal residual immunity to the vaccinia virus in the Australian population. Although humoral immunity is protective against orthopoxvirus infections, cell-mediated immunity and immunological memory likely also play roles, which are not quantified by antibody levels. These data provide an immunological snapshot of the NSW population, which could inform emergency preparedness planning and outbreak control, especially concerning the stockpiling of vaccinia vaccine.https://www.mdpi.com/1999-4915/12/5/554smallpoxvaccine immunityresponse planningpopulation immunity |
| spellingShingle | Valentina Costantino Mallory J. Trent John S. Sullivan Mohana P. Kunasekaran Richard Gray Raina MacIntyre Serological Immunity to Smallpox in New South Wales, Australia Viruses smallpox vaccine immunity response planning population immunity |
| title | Serological Immunity to Smallpox in New South Wales, Australia |
| title_full | Serological Immunity to Smallpox in New South Wales, Australia |
| title_fullStr | Serological Immunity to Smallpox in New South Wales, Australia |
| title_full_unstemmed | Serological Immunity to Smallpox in New South Wales, Australia |
| title_short | Serological Immunity to Smallpox in New South Wales, Australia |
| title_sort | serological immunity to smallpox in new south wales australia |
| topic | smallpox vaccine immunity response planning population immunity |
| url | https://www.mdpi.com/1999-4915/12/5/554 |
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