COVID booster dose: what’s the key to expanding the vaccine universe

While some countries are making their best efforts to become inoculants and protect their populations from the threat of the Delta variant around the world, experts are debating the need to increase defenses with booster doses of the available formulations.

There is some evidence that immunity wanes over time, especially against the worrisome Delta variant, however, The researchers found that while a single dose of the Oxford-AstraZeneca or Pfizer-BioNTech vaccine is 30% effective against this mutation, two doses are more effective: 88% for Pfizer and 67% for AstraZeneca.

In this context, there is a debate as to whether or not booster shots should take precedence over primary vaccination. In June, researchers from the University of Oxford team that developed the AstraZeneca vaccine said that although a third dose of their vaccine could strongly boost the immune response, there was no indication that a recall was necessary and stressed that the “urgent priority” must be to ensure that people around the world get their first dose.

Despite nearly 35 million doses of COVID-19 administered each day, only 1.3% of people in low-income countries received at least one dose.. Just under a third (32%) of the world’s population have received at least one dose, and only a quarter (24%) have received two, according to the British Medical Journal (BMJ).

The World Health Organization (WHO) has raised the possibility of postponing reinforcements at least until the end of September, to allow a minimum of 10% of the population of each country to be vaccinated. WHO Director-General Tedros Adhanom Ghebreyesus said in a speech on August 4: “I understand the concern of all governments to protect their people from the Delta variant. But we cannot accept that countries that have already used up most of the global vaccine supply are using even more, while the world’s most vulnerable people remain unprotected. “

Which countries are already planning booster injections?

Many high- and middle-income countries were discussing booster doses (a third dose, in most cases) as a way to ensure that people remain protected against the new variants of SARS-CoV-2 as the winter months approach.

In Israel, more than a million people have received a third dose of the Pfizer vaccine after the government began its campaign targeting those over 50.

Turkey started giving booster doses in July to healthcare workers and people over 50. The country, which uses the Sinovac and Pfizer vaccines, now also allows people who have received the Sinovac vaccine to also receive the Pfizer vaccine so that they can travel to countries that do not recognize the Chinese vaccine.

A similar initiative is being implemented in Uruguay, where citizens who have received the Sinovac vaccine are offered a dose of the Pfizer vaccine to boost their immune response. And in Cambodia and Thailand, the AstraZeneca vaccine is offered as a booster to people who have received the Sinovac or Sinopharm vaccine.

US Should Implement Booster Vaccines for most adults from September 20, and it is recommended that the third dose be administered eight months after the second. Healthcare workers, nursing home residents and the elderly who received the vaccines early will be prioritized for the recall.

However, so far, the United States Food and Drug Administration, which on Monday gave the final authorization of the Pfizer vaccine, only changed the emergency use authorizations for Pfizer and Moderna vaccines, to allow the administration of a third booster dose to certain immunocompromised individuals, including organ transplant recipients and those whose diagnosed condition is considered to have an equivalent level of immunosuppression.

The FDA is reviewing the safety and effectiveness of the booster dose in other members of the adult population, while the Centers for Disease Control and Prevention is reviewing the evidence.

In the UK, the healthcare system prepared to roll out a booster dose in September for patients considered to be at risk of serious illness. However, The Times newspaper reported that the UK Joint Committee on Vaccination and Immunization is awaiting more data before making a final decision on whether to recommend a booster program.

France and Germany also plan to launch the third dose of the vaccine in September for the elderly and vulnerable, including the immunocompromised and residents of nursing homes. Ecuador plans to implement booster doses of Pfizer, AstraZeneca and Sinovac vaccines for people with weakened immune systems. His health ministry said it would conduct an investigation to determine whether the general population should also receive a third dose.

About the brand mark

The combination of vaccines is another of the strategies that several states have implemented in the midst of the pandemic.

At this point, Uruguay, Cambodia and Thailand are mixing the vaccines, while the United States has decided not to combine the brands and has already announced that people who have received two doses of the Pfizer or Moderna vaccines will be able to get one. third dose of the same vaccine. . However, those who have received a dose of Johnson & Johnson will not yet be offered a second application, as officials await clinical results of the drug company’s efficacy of the serum.

In Ireland, the vaccine brands will be mixed, with people who have received a single dose of the AstraZeneca vaccine but did not choose to receive a second dose and are currently being offered a dose of the Pfizer or Moderna vaccine. The vaccine mix will likely be cleared when the booster doses are released in October.

Could annual COVID vaccines be needed?

“It is definitely a possibility,” Anthony Harnden, member of the UK Committee for Immunization and Immunization, told BMJ magazine. And I add: “I suspect we’ll probably need an annual boost for a while. It just depends on the length of protection. The virus mutates, but probably does not mutate as much or as fast as the flu virus, it is therefore very difficult to predict whether it will be an annual vaccine or for how many years ”.

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