INs potential Covid-19 vaccines make their way through development, manufacturers and U.S. regulators have tested for many delays in children and women who are pregnant, and increase the possibility that experts will miss critical safety and efficacy data in those populations if there is an urgent need to impulse them.
Vaccines are always tested first in healthy adults, a population that is most likely to give a clear picture when a vaccine triggers protection. It is also a population that is considered to have the lowest risk if there are side effects of an experimental vaccine.
But the Covid-19 pandemic has launched a race to vaccinate all Americans as soon as possible, beginning early next year. Although most experts claim that children and women who are pregnant or breastfeeding will not be at the forefront when the first doses are available, others see a need for answers as to whether the vaccines are safe and effective in these populations sooner. then letter.
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“There will be enormous pressure to vaccinate children because of schools … so that we can open schools more safely,” said Michael Osterholm, director of the University of Minnesota’s Center for Infectious Diseases Research and Policy.
Manufacturers who tested the vaccines in clinical trials have so far not included pregnant women or women who are breastfeeding. And only one of the fax makers that could end up delivering to the US market, AstraZeneca, has started testing its vaccine in children.
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Meanwhile, given the predominance of women of reproductive age working in health care as first responders, any plan to put workers from those sectors at the forefront of the vaccine line should take the certainty that women who they are heavy. At least some of them may not know it by the time they get vaccinated.
“I think there is a recognition that if we do not have a vaccine that we can reasonably offer for safe use during pregnancy, then we will have a real problem in terms of covering the populations we know we need to cover. , ”Said Carleigh Krubiner, a policy fellow at the Center for Global Development, a think tank in Washington.
Women who are pregnant have historically been excluded from all types of clinical trials. Krubiner, who is part of a collaboration that has the need to include pregnant women in testing new vaccines, said this time that she knew the problem was on people’s radar, but the studies have not started yet.
“There is certainly a plausible scenario where we have an authorization for emergency use [for a vaccine] as a licensed product where there is no heavy data on the product during pregnancy, ”she told STAT.
Other populations are traditionally slower to be invited to participate in clinical trials for vaccines, either because of perceived risks to them, or because the data generated when they are vaccinated may not provide the most compelling evidence for efficacy. . People who are HIV-positive are an example of the older, older and older adults, whose immune system is less effective, an example of the latter.
However, both of these groups are already enrolled in clinical trials for Covid-19 vaccines.
A Phase 1/2 clinical trial testing the Oxford University-AstraZeneca vaccine in South Africa involves an arm in which 50 people are living with HIV. And a Phase 2b trial of Novavax’s candidate vaccine announced this week in the same nation will enroll 240 people who have HIV and who are medically stable. Under pressure from advocacy groups, Moderna recently changed its plans for its Phase 3 trial to include people with HIV.
While they are advanced to Phase 3 trials, several manufacturers of vaccine tests in the US have expanded their volunteer pools to include people 65 and older. Moncef Slaoui, co-chair of the administration’s Warp Speed Operation, said at a recent meeting of a National Academy of Sciences committee that the initiative requires all vaccine projects it funds to include older adults in its trials. .
When asked if the subjects enrolled pregnant women, Slaoui said no.
The Food and Drug Administration indicated to manufacturers that it wanted tests to be conducted in both of these key groups when it issued its guidance for Covid-19 vaccines in June. But the agency stated that studies for developmental and reproductive toxicity in animals should be conducted before candidate vaccines are tested in pregnant and lactating women.
At least one of the manufacturers, Pfizer, is in the process of conducting these tests, and will present the data to the FDA, a spokesman for the company told STAT.
Other experts say there are encouraging signs.
Julie Ledgerwood, of the National Institute for Allergy and Infectious Disease’s Vaccine Research Center, said all manufacturers have these types of discussions.
And Kathleen Neuzil, director of the Center for Vaccine Development at the University of Maryland School of Medicine, said she believes “the paradigm has shifted.”
‘I think most people feel that pregnant women should be admitted early. They have the capacity to make informed decisions and decide if they want to be part of a trial, ”she said.
Larry Corey, co-leader of the National Institutes of Health’s Covid-19 Prevention Network, said ensuring vaccines are safe for pregnant women “is of great importance” to U.S. vaccine development efforts.
“Commitment with regulatory agencies and companies is underway to initiate such evaluations,” Corey, a vaccine expert at the Fred Hutchinson Cancer Research Center, said in an email. “In the same way, conversations are underway … to discuss plans for initiating studies in children.”
Outside the U.S., two clinical trials of a Covid-19 vaccine candidate in China were open to children as young as 6 months, according to the clinical trial registry ClinicalTrials.gov. No data from the trials have been published yet. A trial with a vaccine in India allowed people aged 12 to 65 to enroll.
Then there is the Oxford-AstraZeneca Phase 2/3 trial, one arm of which tests the safety of its vaccine in children aged 5 to 12 years. Neuzil, who is the other co-leader of the NIH network, said she expects more. “We have an expert group of pediatricians reviewing this and it will be done in a cautious way of escalating age,” she said.
Osterholm, who warned for weeks that the repayment of personal schooling and the return of university students to campuses would lead to the emergence of cases, thinks these studies can not be done too soon. Already, the University of North Carolina has reversed a decision to hold classes in person after Covid-19 cases among students and staff quickly escalated.
Opening schools and keeping them open will require children to be vaccinated, Osterholm said. “That’s why we need to have security data.”
