COVID-19 vaccine combination may exceed performance of NMRA vaccines: Nature

ECONOMYNEXT – Mixing and pairing Covid 19 vaccines are very effective in preventing disease and may exceed the performance of standard mRNA vaccines, according to international studies.

British scientific journal Nature reported on Friday (21) that several studies around the world have shown that ‘mix and match’ diets are very effective in preventing COVID-19, roughly matching or even exceeding the performance of mRNA vaccines.

The high levels of antibodies and other strong immune responses elicited by mixed diets suggest that they may offer good protection against the disease.

Nature reported that the studies arose out of a natural experiment that began in March, when a number of countries partially or completely stopped using the vaccine developed by the University of Oxford and the pharmaceutical company AstraZeneca in Cambridge , in the UK, due to extremely rare cases but serious side effects.

“This meant that some people who had already received a dose of this vaccine then had a different vaccine as a second vaccine,” Nature noted.

“I was delighted to see that it is as effective as one would expect. This is very good news and it will certainly have an influence on clinical practice, ”said the journal, citing immunologist Martina Sester of Aarland University in Homburg, Germany.

Nature citing Matthew Snape, a vaccinologist at the University of Oxford, UK, said these emerging efficacy data supports the use of these approved COVID-19 vaccines in standard or mixed schedules.

The studies were performed in Sweden, Denmark and France by examining various populations at various times, including during the rise of the hyperinfectious variant Delta. All three studies agreed that mixed, or heterologous, vaccination is highly protective.

In Sweden, health authorities had severely reduced the use of the Oxford-AstraZeneca vaccine, which is based on a weakened chimpanzee cold virus. More than 100,000 people in Sweden have received a dose of AstraZeneca, followed by an mRNA-based vaccine, either the vaccine from Moderna in Cambridge, Massachusetts, or the one developed by the New York-based pharmaceutical company Pfizer, and the biotechnology company BioNTech in Mainz. , Germany.

After analyzing the data, scientists at Umeå University in Sweden found that, compared to unvaccinated people, people on a mixed vaccination schedule were 68% less likely to develop symptomatic infection, while those on a mixed vaccination schedule were 68% less likely to develop symptomatic infection. 430,000 people who received two doses of AstraZeneca were 50% less likely to do this.

“These and other figures clearly show that heterologous treatment regimens are more effective than two doses of AstraZenec,” said scientists at Umeå University in Sweden.

According to Nature, another study in Denmark that has not yet been peer reviewed found that a dose of AstraZeneca followed by a dose of Pfizer-BioNTech was 88% effective in preventing SARS-CoV infection -2 and is similar in effectiveness to two doses of Pfizer.

However, a study in France showed that the rates of SARS-CoV-2 infection in the mix-and-match group were half of those in the group that received two doses of Pfizer. The scientist from Inserm and the University of Lyon in France showed these results after analyzing data from 2,512 health workers who received a combination of AstraZeneca and Pfizer vaccines, and more than 10,000 who received two doses of the latter.

Scientists say the mixed COVID-19 vaccines may have passed the efficacy test, but questions remain, such as how long the mixed and assorted vaccines hold over time, and if and when they need a booster with additional doses.

Nature reported that unpublished data from Umeå University in Sweden showed that the durability of protection conferred by mixed vaccines is comparable to that of mRNA vaccines. However, the data also suggests that those at higher risk would benefit from a third dose.

Scientists say mixing and pairing vaccines may better protect organ transplant recipients and others with weakened immune systems than the standard vaccination schedule.

After analyzing the data from the studies, Sri Lanka decided on Friday (22) that the booster dose program would start from the first week of November.

Army Commander Gen. Shavendra Silva, who also heads the national COVID-19 task force, told reporters on Friday that the Pfizer-BioNTech COVID-19 vaccine will be given as a booster dose for frontline workers in the fields of health, army, police and tourism. sectors from 01 November. (Colombo / October 22/2021)

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