{"id":115608,"date":"2021-06-29T15:30:05","date_gmt":"2021-06-29T22:30:05","guid":{"rendered":"http:\/\/www.lankaweb.com\/news\/items\/?p=115608"},"modified":"2021-06-29T15:30:05","modified_gmt":"2021-06-29T22:30:05","slug":"mix-and-match-approach-boosts-immune-response-covid-vaccine-study-finds","status":"publish","type":"post","link":"https:\/\/www.lankaweb.com\/news\/items\/2021\/06\/29\/mix-and-match-approach-boosts-immune-response-covid-vaccine-study-finds\/","title":{"rendered":"Mix-and-match approach boosts immune response, COVID vaccine study finds"},"content":{"rendered":"

Courtesy Adaderana<\/em><\/span><\/h2>\n\n\n

A mix-and-match approach to COVID vaccines – using different brands of jab for first and second doses – gives good protection against the pandemic virus, a UK study has found.<\/p>\n\n\n\n

The Com-Cov trial looked at the efficacy of either two doses of Pfizer, two of AstraZeneca, or one of them followed by the other.<\/p>\n\n\n\n

All combinations worked well, priming the immune system.<\/p>\n\n\n\n

This knowledge could offer flexibility for vaccine rollout, say experts.<\/p>\n\n\n\n

The trial results also hint that people who have already received two doses of AstraZeneca vaccine could have a stronger immune response if they were given a different jab as a booster if recommended in the autumn.<\/p>\n\n\n\n

The UK\u2019s deputy chief medical officer, Prof Jonathan Van-Tam, said there was no reason to change the current successful same dose vaccine schedules in the UK, however, given vaccines were in good supply and saving lives.<\/p>\n\n\n\n

But he says it might be something to look at in the future: Mixing doses could provide us with even greater flexibility for a booster programme, while also supporting countries who have further to go with their vaccine rollouts, and who may be experiencing supply difficulties.\u201d<\/p>\n\n\n\n

Some countries are already using mixed doses. Spain and Germany are offering the Pfizer or Moderna mRNA vaccines as a second dose to younger people who have already received a first dose of the AstraZeneca vaccine, following concerns about rare but serious blood clots, rather than about efficacy.<\/p>\n\n\n\n

Two doses are important to give the fullest protection and teach the body to make antibodies and T cells to block and kill COVID.<\/p>\n\n\n\n

The Com-Cov study, which looked at giving the doses four weeks apart in 850 volunteers aged 50 and above, found:<\/p>\n\n\n\n

\u2022 AZ followed by Pfizer induced higher antibodies and T cell responses than Pfizer followed by AZ<\/p>\n\n\n\n

\u2022 Both of these mixes induced higher antibodies than two doses of AZ<\/p>\n\n\n\n

\u2022 The highest antibody response was seen after two doses of Pfizer, and the highest T cell response from AZ followed by Pfizer<\/p>\n\n\n\n

Lead investigator Prof Matthew Snape, from the University of Oxford, said the findings did not undermine the UK policy of giving people the same jab twice: We already know that both standard schedules are very effective against severe disease and hospitalisations, including against the Delta variant when given at eight to 12 weeks apart.\u201d<\/p>\n\n\n\n

He said the new results showed mixed dose schedules were also effective, even though the interval of four weeks studied was shorter than the eight to 12-week schedule most commonly used in the UK.<\/p>\n\n\n\n

This longer interval is known to result in a better immune response,\u201d he added.<\/p>\n\n\n\n

Mixed dose trial results for a 12-week jab interval will be available next month.<\/p>\n\n\n\n

Autumn booster dose?<\/p>\n\n\n\n

Meanwhile, another pre-print study, which also came out on Monday, suggests a third dose of AZ vaccine, given more than six months after the second, boosts the immune system.<\/p>\n\n\n\n

But experts say it is too early to know if people will need a booster dose this year ahead of winter. It is unclear yet how much immunity might wane over time.<\/p>\n\n\n\n

Prof Paul Hunter from the University of East Anglia said: The big question at present is whether or not we will be being offered booster vaccines in the autumn. With the evidence available from this and other sources, I suspect that will be likely for those most at risk from the virus, either due to age or being clinically vulnerable.\u201d<\/p>\n\n\n\n

He suggested people who have had a first course of AstraZeneca might be offered the Pfizer vaccine in as a booster rather than a repeat AstraZeneca, while people who had a Pfizer first course may not need an autumn booster, based on the evidence from the Com-Cov trial.<\/p>\n\n\n\n

Source: BBC
-Agencies<\/p>\n","protected":false},"excerpt":{"rendered":"

Courtesy Adaderana A mix-and-match approach to COVID vaccines – using different brands of jab for first and second doses – gives good protection against the pandemic virus, a UK study has found. The Com-Cov trial looked at the efficacy of either two doses of Pfizer, two of AstraZeneca, or one of them followed by the […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":true,"template":"","format":"standard","meta":{"footnotes":""},"categories":[122,174],"tags":[],"class_list":["post-115608","post","type-post","status-publish","format-standard","hentry","category-health","category--19-"],"_links":{"self":[{"href":"https:\/\/www.lankaweb.com\/news\/items\/wp-json\/wp\/v2\/posts\/115608","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.lankaweb.com\/news\/items\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.lankaweb.com\/news\/items\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.lankaweb.com\/news\/items\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.lankaweb.com\/news\/items\/wp-json\/wp\/v2\/comments?post=115608"}],"version-history":[{"count":0,"href":"https:\/\/www.lankaweb.com\/news\/items\/wp-json\/wp\/v2\/posts\/115608\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.lankaweb.com\/news\/items\/wp-json\/wp\/v2\/media?parent=115608"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.lankaweb.com\/news\/items\/wp-json\/wp\/v2\/categories?post=115608"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.lankaweb.com\/news\/items\/wp-json\/wp\/v2\/tags?post=115608"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}