There may be more vaccines than people who want them by mid-May. Here’s why that’s a big problem.

Us Health Virus Vaccine
A nurse waits at an empty table for more patients to arrive to receive a dose of the Moderna Covid-19 vaccine at a Veterans Administration (VA) Long Beach Healthcare System pop-up vaccination site at the Dae Hueng Presbyterian Church on April 17, 2021 in Gardena, California. (Photo by Patrick T. FALLON / AFP) (Photo by PATRICK T. FALLON/AFP via Getty Images)

(CNN) — By mid-May, the US will likely be coming up against a significant obstacle in the fight against the Covid-19 pandemic — more doses of the vaccines than people who are willing to receive them, according to data that is worrying experts.

“Facebook runs a survey every day — and we look at that data on a daily basis — and that’s shown that vaccine confidence in the US has been slowly but steadily going down since February,” said Dr. Chris Murray, chair of the Institute for Health Metrics and Evaluation at the University of Washington

“We were at 75% of adults saying they wanted the vaccine,” he told CNN’s Anderson Cooper. “Now we’re down to, in those surveys, about to about 67%.”

Health officials — including Dr. Anthony Fauci — estimate that somewhere between 70% to 85% of the country needs to be immune to the virus — either through inoculation or previous infection — to suppress its spread.

In its latest projection, IHME said about 602,723 Americans will have died from coronavirus by August 1, down from last week’s estimate of at least 618,000 deaths.

The IHME noted that the expansion of vaccination and declining seasonality have been enough to stop deaths from increasing but it warned of hesitancy.

“Given how central vaccination is to the US strategy to control the B.1.1.7 potential surge, the slow erosion of vaccine confidence unfolding over the last two or more months is cause for concern,” the IHME stated.

The seven-day average of new Covid-19 doses administered continued to fall Friday and sits under 3 million for the second consecutive day, according to CDC data.

Already, the military is seeing a surplus of doses and a steady decline in the rate at which they are used.

“We have heard anecdotally that younger people may feel that they’re not as vulnerable to COVID and that perhaps the risk of getting vaccination is higher than getting the disease, which of course we know not to be true,” said Acting Asst. Defense Secretary for Health Affairs Terry Adirim at a press briefing this week.

But concerns about one of the vaccines is believed to have also increased hesitancy.

On Friday, after pausing administration of the Johnson & Johnson vaccine while investigating a rare six cases of blood clotting syndrome among women who received it, the US Centers for Disease Control and Prevention and the Food and Drug Administration recommending resuming its use.

J&J pause ups the need for vaccine education

But to address concerns, CDC director Dr. Rochelle Walensky said the organization is even more pressed to educate the public on vaccine safety and efficacy.

“I think we have to do extraordinary outreach to clinicians — as we have been doing this past week, we already have plans to start that on Monday to public health officials — and then we have to do extraordinary outreach to patients, to meet people where they’re at, to educate them,” Walensky said at a joint conference held by the CDC and US Food and Drug Administration.

“Overall, I actually think that this pause conveyed that we are taking every one of these needles in haystacks that we find seriously — that we’re really examining, scrutinizing the data that we’re seeing.”

At most, resuming administration of the J&J vaccine would result in a few dozen rare blood clots while saving hundreds of lives, a CDC analysis shows.

“When resuming vaccination among all persons at least 18 years, we expect 26 to 45 TTS cases depending on vaccine uptake,” CDC’s Dr. Sara Oliver said, referring to the rare blood clots known as thrombosis-thrombocytopenia syndrome. But 600 to 1,400 deaths from Covid-19 would be prevented, and as many as 3,500 ICU admissions would be prevented.

The Moderna and Pfizer/BioNTech vaccines, meanwhile, have not been associated with blood clots, a US Centers for Disease Control and Prevention expert said Friday.

Study shows how to reduce infections in children

While vaccines remain unavailable to children, new research suggests that testing in school and the vaccination of adults may lower infections in children.

So far, no vaccines are authorized for people younger than 16, but a study published in the medical journal JAMA Network Open on Friday showed that quickly identifying and contact tracing children to identify “silent infections” of Covid-19, where the disease is either presymptomatic or asymptomatic, combined with vaccination of 40-60% adults could significantly reduce the amount of disease.

In a different scenario, where silent infections remained undetected, researchers estimated that children would need an 81% vaccination rate, in addition to 40% of adults being vaccinated, in order to achieve a similar infection rate.

As more students return to the classroom, the study provides a road map to continuing reducing the spread of the virus even before children are eligible for the shots.

CDC recommends pregnant people get vaccinated

Clinical trials of vaccines against coronavirus did not include pregnant women, so there was limited data on the safety of vaccinating pregnant people and babies. But Walenksy recommended Friday that pregnant people get inoculated.

Her comment follows a new study that found no safety concerns among a large group of pregnant people who received the vaccine in their third trimester, and no safety concerns for their babies.

“As such, CDC recommends that pregnant people receive the Covid-19 vaccine,” Walensky said during a White House briefing. “We know that this is a deeply personal decision, and I encourage people to talk to their doctors or primary care providers to determine what is best for them and for their baby.”

On Wednesday, the New England Journal of Medicine published preliminary findings from CDC scientists that determined that the mRNA Covid-19 vaccines made by Pfizer and Moderna do not appear to pose any serious risk during pregnancy.

Last month, another study published in the American Journal of Obstetrics and Gynecology found mRNA Covid-19 vaccines are effective in pregnant and lactating women, and they can pass protective antibodies to newborns.