Booster AstraZeneca OK, according to the newspaper; SII asks for a nod

Seven Covid-19 vaccines are safe and stimulate a strong immune response when given as a booster to people who have previously received two-dose treatment with Oxford-AstraZeneca or Pfizer-BioNTech, according to the first randomized trial of this type of recalls published in The Lancette.

So far, little data existed. As SII demands a nod, the booster trial clarifies AstraZeneca on the comparative safety of Covid vaccines and the immune responses they stimulate as a third dose. Lancet’s COV-BOOST study, based on a UK trial, looked at the safety, immune response and side effects of seven vaccines when used as a third booster shot after 10 to 11 weeks.

The seven vaccines given as a third dose were AstraZeneca, Pfizer, Novavax, Janssen, Moderna, Valneva and Curevac. “Side effect data show that all seven vaccines can be safely used as a 3rd dose, with acceptable levels of inflammatory side effects like injection site pain, muscle pain, fatigue,” said Professor Saul Faust, head of the trial and director of the NIHR Clinical Research Center, University Hospital Southampton NHS Foundation Trust, said.

But while all seven vaccines boosted peak protein immunogenicity after two doses of AstraZeneca, in Pfizer’s case, after two doses, a booster dose of Valneva was not found to be effective.

The Serum Institute has asked the Drug Controller General of India to authorize the use of Covishield as a booster.

While the AstraZeneca vaccine is administered in over 180 countries, Pfizer is available in over 145 countries. Two doses of the vaccine, respectively, were found to provide 79% and 90% protection against hospitalization and death for up to six months after administration in several studies. However, protection is known to wane over time, resulting in demand for callbacks, especially for the most vulnerable, and to reduce pressure on health services and lessen the economic impact.

Professor Faust said: “It is really encouraging that a wide range of vaccines, using different technologies, have advantages as a third dose for AstraZeneca or Pfizer. This gives confidence and flexibility in developing recall programs here in the UK and around the world, with other factors such as supply chain and logistics also at play. ”

More research is needed to determine the effectiveness of boosters on long-term protection and immunological memory. The researchers said studies were underway to determine the effectiveness of two of the vaccines in people who received the third dose much later, after seven to eight months.

The phase 2 randomized trial involved 2,878 healthy participants, recruited from 18 UK sites between 1 and 30 June 2021, in a mix of community and secondary care settings. All were 30 years or older, with half of them over 70. Participants received their first doses in December 2020, or January-February 2021, and second doses at least 70 days before enrolling in the study in the case of Astrazeneca and 84 days in the case of Astrazeneca. Oxford.

Adverse reactions after seven days and antibody levels after 28 days were the main reason for the study. The other outcome studied was the immune response of T lymphocytes. While in the case of AstraZeneca, antibody levels increased from 1.8-fold to 32.3-fold depending on the booster used, in the case of Pfizer, the increase was from 1.3 times to 11.5 times. Significant T cell responses have been reported in several combinations. At 28 days, all recall results were similar.

Among the side effects, fatigue, headache, and pain at the injection site were the most common. Of the 2,878 participants, 912 experienced a total of 1,036 “adverse events”, 24 of which were serious.

The authors cautioned that the booster data should be interpreted with caution as it relates to immunogenicity rather than protection against disease, and the relationship between antibody levels at day 28 and long-term protection and immunological memory. is unknown.

Other limitations of the study included that due to the pandemic and the need to generate data to inform policy in September 2021, the interval between doses varied. Several studies have shown that a longer period of time between the first and second dose can improve immunogenicity, including enhancing antibody responses.

Additionally, recruiting people over the age of 30 limits results, as studies have shown that vaccines tend to cause a stronger immune response in young people and greater side effects. The participants were also predominantly white.

This study was funded by the UK Vaccine Taskforce and the National Institute for Health Research. It was conducted by researchers at University Hospital Southampton NHS Foundation Trust, University of Southampton, Imperial College London, University of Oxford, NIHR Oxford Biomedical Research Center and the Oxford Vaccine Group.

Study researchers said policymakers should establish criteria for choosing which booster vaccines to use, based on immunological considerations, known side effect profiles, availability in the country and, ultimately, the sufficient recall level in the context of a national strategic disease. control objectives.

At a press briefing on Thursday, officials from the Union’s health ministry said on booster doses their priority was clear. “Complete the task of vaccinating all adults with both doses – this is the goal and strategy that will give us the best dividend at this time,” said Dr VK Paul, Member, Health, NITI Aayog.


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