Post by icemandios on Aug 30, 2022 19:44:45 GMT
August 30, 2022 12:20 PM EDTUpdated 01:49 PM Coronavirus
Latest Covid-19 shots are almost ready: Why is the US authorizing a different booster than the rest of the world?
Zachary Brennan
Senior Editor
The US FDA later this week will authorize the latest weapon in the ever-shifting battle against Covid-19, setting up another national campaign to get the free shots into arms ahead of winter.
But the decision comes with some drama (as each of the prior authorizations has) because this newest booster is not only the first bivalent vaccine for Covid in the US, but also arrives without human data, and it’s a different booster from what other high-income countries are authorizing.
The US is about to sign off on two different booster doses — one from Pfizer, the other from Moderna — of an Omicron BA.4/BA.5-adapted bivalent vaccine, with about 170 million doses available initially for everyone over the age of 12. While the boosters will be aimed at those who have completed a primary vaccination series, the CDC notes in its planning guide that the type and number of boosters that people have previously received are not expected to matter for the purposes of eligibility for these latest bivalent shots.
“It’s a bivalent vaccine — so half of it is still the original virus, which we know is effective, and the other half is toward this new circulating variant. An immune response is generated in preclinical models, but we’re early on, and to stay ahead of the curve, we have to develop these quickly,” FDA commissioner Rob Califf told a Johns Hopkins podcast today. “You have to be preemptive in a pandemic.”
What’s controversial about these boosters isn’t likely to be their safety, given the hundreds of millions who’ve already safely received one of these mRNA vaccines over the past several years, but how protective and beneficial they are in keeping vulnerable populations from hospitalization or death, and whether that protection is greater than the currently available mRNA vaccines.
Paul Offit, a pediatrician at the Children’s Hospital of Philadelphia and member of the FDA’s vaccine adcomm, told Endpoints News that he thinks boosters are necessary but only for select groups, such as the elderly (75+) and those with serious underlying health conditions, to continue to protect against severe disease.
But he questioned the need to boost the entire population, given that such a campaign is unlikely to slow the spread of this virus at this point nationally, as he predicts this virus in some form is likely to be with us for decades.
“The notion of vaccinating the entire population to decrease the spread is impossible,” Offit added. “We’re not going to stop the virus from circulating.”
He also said that there needs to be some human data presented, as there are currently only data from mice for these BA.4/5-targeted boosters, and he’s hoping some of that new data (Moderna and Pfizer trials are ongoing) will be shared at the CDC’s ACIP meeting on Thursday and Friday.
While Offit expressed disappointment that the FDA’s VRBPAC didn’t meet to discuss this latest booster application, if only to present this new data openly to the public, and to allow experts to voice what they think are the strengths and weaknesses of that data, it’s unclear if that VRBPAC meeting would’ve changed the FDA’s authorization or the rollout following Labor Day weekend.
“In this case we have a free intervention with very few side effects … it’s painful to see 90+% of people dying from Covid who are not up to date on their vaccines,” Califf added.
Meanwhile, prior to the FDA’s decision on these two EUAs, regulators in the UK, Switzerland and Australia have signed off on a different, BA.1-adapted bivalent vaccine, which does have some clinical data to show for it.
Moderna said these new authorizations are based on clinical trial data from a Phase II/III trial, in which mRNA-1273.214 met all primary endpoints, and it elicited potent neutralizing antibody responses against the Omicron subvariants BA.4 and BA.5 compared to the original vaccine, regardless of prior infection status or age.
But Offit questioned the move to target a sublineage of Omicron that is no longer circulating in these countries, saying he thinks the US made the right move to target BA.4/5, even if the US should’ve waited to see if it shows any added benefit, he said.
Latest Covid-19 shots are almost ready: Why is the US authorizing a different booster than the rest of the world?
Zachary Brennan
Senior Editor
The US FDA later this week will authorize the latest weapon in the ever-shifting battle against Covid-19, setting up another national campaign to get the free shots into arms ahead of winter.
But the decision comes with some drama (as each of the prior authorizations has) because this newest booster is not only the first bivalent vaccine for Covid in the US, but also arrives without human data, and it’s a different booster from what other high-income countries are authorizing.
The US is about to sign off on two different booster doses — one from Pfizer, the other from Moderna — of an Omicron BA.4/BA.5-adapted bivalent vaccine, with about 170 million doses available initially for everyone over the age of 12. While the boosters will be aimed at those who have completed a primary vaccination series, the CDC notes in its planning guide that the type and number of boosters that people have previously received are not expected to matter for the purposes of eligibility for these latest bivalent shots.
“It’s a bivalent vaccine — so half of it is still the original virus, which we know is effective, and the other half is toward this new circulating variant. An immune response is generated in preclinical models, but we’re early on, and to stay ahead of the curve, we have to develop these quickly,” FDA commissioner Rob Califf told a Johns Hopkins podcast today. “You have to be preemptive in a pandemic.”
What’s controversial about these boosters isn’t likely to be their safety, given the hundreds of millions who’ve already safely received one of these mRNA vaccines over the past several years, but how protective and beneficial they are in keeping vulnerable populations from hospitalization or death, and whether that protection is greater than the currently available mRNA vaccines.
Paul Offit, a pediatrician at the Children’s Hospital of Philadelphia and member of the FDA’s vaccine adcomm, told Endpoints News that he thinks boosters are necessary but only for select groups, such as the elderly (75+) and those with serious underlying health conditions, to continue to protect against severe disease.
But he questioned the need to boost the entire population, given that such a campaign is unlikely to slow the spread of this virus at this point nationally, as he predicts this virus in some form is likely to be with us for decades.
“The notion of vaccinating the entire population to decrease the spread is impossible,” Offit added. “We’re not going to stop the virus from circulating.”
He also said that there needs to be some human data presented, as there are currently only data from mice for these BA.4/5-targeted boosters, and he’s hoping some of that new data (Moderna and Pfizer trials are ongoing) will be shared at the CDC’s ACIP meeting on Thursday and Friday.
While Offit expressed disappointment that the FDA’s VRBPAC didn’t meet to discuss this latest booster application, if only to present this new data openly to the public, and to allow experts to voice what they think are the strengths and weaknesses of that data, it’s unclear if that VRBPAC meeting would’ve changed the FDA’s authorization or the rollout following Labor Day weekend.
“In this case we have a free intervention with very few side effects … it’s painful to see 90+% of people dying from Covid who are not up to date on their vaccines,” Califf added.
Meanwhile, prior to the FDA’s decision on these two EUAs, regulators in the UK, Switzerland and Australia have signed off on a different, BA.1-adapted bivalent vaccine, which does have some clinical data to show for it.
Moderna said these new authorizations are based on clinical trial data from a Phase II/III trial, in which mRNA-1273.214 met all primary endpoints, and it elicited potent neutralizing antibody responses against the Omicron subvariants BA.4 and BA.5 compared to the original vaccine, regardless of prior infection status or age.
But Offit questioned the move to target a sublineage of Omicron that is no longer circulating in these countries, saying he thinks the US made the right move to target BA.4/5, even if the US should’ve waited to see if it shows any added benefit, he said.