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New Delhi, Aug 18 (PTI): Vaccine stockpiling by nations may strongly impact global trajectories of COVID-19 case numbers, and increase the potential emergence of novel variants of the SARS-CoV-2 virus, a modelling study has warned.<\/p>\n
The research, published in the journal Science on Tuesday, explored the effects of different vaccine-sharing schemes on the global persistence of COVID-19 infections, as well as the possibility for the evolution of new variants, using mathematical models.<\/p>\n
The researchers noted that allocation of COVID-19 preventives between countries has so far tended towards vaccine nationalism, wherein countries stockpile vaccines to prioritise access for their citizenry over equitable vaccine sharing.<\/p>\n
\u201cCertain countries that have had severe COVID-19 outbreaks have received few vaccines, while many doses have gone to countries experiencing comparatively milder pandemic impacts, either in terms of mortality or economic dislocation,\u201d said study co-first author Caroline Wagner, an assistant professor at McGill University in Canada.<\/p>\n
\u201cAs expected, we have seen large decreases in case numbers in many regions with high vaccine access, yet infections are resurging in areas with low availability,\u201d study co-first author Chadi Saad-Roy, a graduate student at Princeton University in the US, added.<\/p>\n
The researchers projected the incidence of COVID-19 cases under a range of vaccine dosing regimes, vaccination rates, and assumptions related to immune responses.<\/p>\n
They did so in two model regions: One with high access to vaccines \u2014 a high-access region (HAR) \u2014 and a low-access region (LAR).<\/p>\n
The models also allowed for the regions to be coupled either through case importation, or the evolution of a novel variant in one of the regions.<\/p>\n
The study found that increased vaccine-sharing resulted in reduced case numbers in LARs.<\/p>\n
\u201cBecause it appears that vaccines are highly effective at reducing the clinical severity of infections, the public health implications of these reductions are very significant,\u201d said study co-author Michael Mina, an assistant professor at the Harvard T H Chan School of Public Health, US.<\/p>\n
Senior study author C Jessica Metcalf, a Princeton associate professor, noted that high case numbers in unvaccinated populations will likely be associated with higher numbers of hospitalisations and larger clinical burdens compared to highly vaccinated populations.<\/p>\n
The authors also drew on a framework developed in their previous work to quantify the potential for viral evolution under different vaccine sharing schemes.<\/p>\n
In their model, repeat infections in individuals with partial immunity \u2014 either from an earlier infection or a vaccine \u2014 resulted in the evolution of novel variants.<\/p>\n
\u201cOverall, the models predict that sustained elevated case numbers in LARs with limited vaccine availability will result in a high potential for viral evolution,\u201d said study senior author Bryan Grenfell, an associated faculty member in Princeton\u2019s High Meadows Environmental Institute (HMEI).<\/p>\n
\u201cThe study strongly underlines how important rapid, equitable global vaccine distribution is,\u201d Grenfell said.<\/p>\n
The researchers noted that in a scenario where secondary infections in individuals who have previously been infected strongly contribute to viral evolution, unequal vaccine allocation appears particularly problematic.<\/p>\n
Global vaccine coverage will reduce the clinical burden from novel variants, while also decreasing the likelihood that these variants emerge, they added.<\/p>\n","protected":false},"excerpt":{"rendered":"
New Delhi, Aug 18 (PTI): Vaccine stockpiling by nations may strongly impact global trajectories of COVID-19 case numbers, and increase the potential emergence of novel variants of the SARS-CoV-2 virus, a modelling study has warned. The research, published in the journal Science on Tuesday, explored the effects of different vaccine-sharing schemes on the global persistence […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[],"class_list":{"0":"post-169515","1":"post","2":"type-post","3":"status-publish","4":"format-standard","6":"category-national"},"_links":{"self":[{"href":"https:\/\/arunachaltimes.in\/index.php\/wp-json\/wp\/v2\/posts\/169515","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/arunachaltimes.in\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/arunachaltimes.in\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/arunachaltimes.in\/index.php\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/arunachaltimes.in\/index.php\/wp-json\/wp\/v2\/comments?post=169515"}],"version-history":[{"count":0,"href":"https:\/\/arunachaltimes.in\/index.php\/wp-json\/wp\/v2\/posts\/169515\/revisions"}],"wp:attachment":[{"href":"https:\/\/arunachaltimes.in\/index.php\/wp-json\/wp\/v2\/media?parent=169515"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/arunachaltimes.in\/index.php\/wp-json\/wp\/v2\/categories?post=169515"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/arunachaltimes.in\/index.php\/wp-json\/wp\/v2\/tags?post=169515"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}